Typical hazardous tasks in electrical work
The following tasks are some examples of possible exposure to energized conductors:
a) Measuring, testing, and probing electrical system components;
b) Working near battery banks;
c) Opening electrical equipment enclosure doors or removing covers;
d) Inserting or pulling fuses;
e) Drilling, or otherwise penetrating, earth, walls, or ßoors;
f) Pulling conductors in raceways, cable trays, or enclosures;
g) Lifting leads or applying jumpers in control circuits;
h) Installing or removing temporary grounds;
i) Operating switches or circuit breakers;
j) Working inside electronic and communications equipment enclosures.
Showing posts with label Culture. Show all posts
Showing posts with label Culture. Show all posts
NEC FLAMMABLE CONDITIONS BASIC INFORMATION AND TUTORIALS
The National Electrical Code addresses hazardous conditions that create the potential for fires to occur. Environments that pose fire or combustion hazards are listed in Articles 500-510. Requirements covering specific types of facilities that pose additional hazards, such as bulk storage plants or motor fuel dispensing locations, are explained in Articles 511-516.
NEC Section (C)(2)(1) describes Class II, Division 2 locations classifications. These are listed as:
1. Locations where some combustible dust is normally in the air but where abnormal operations may increase the suspended dust to ignitable or explosive levels.
2. Locations where combustible dust accumulations are normally not concentrated enough to interfere with the operation of electrical equipment unless an “infrequent equipment malfunction” occurs that increases the level of dust suspended in the air.
3. Locations where combustible dust concentrations in or on electrical equipment may be sufficient to limit heat dissipation or that could be ignited by failure or abnormal operation of electrical equipment.
A variety of airborne environmental conditions that require classification are listed in Article 500. Class I covers locations specified in Sections [500.5(B)(1)] and [500.5 (B)(2)] where flammable gases or vapors are present, or could exist in the air in high enough quantities that they could produce explosive or ignitable mixtures. Section [500.5(B)(1) FPN 1] provides examples of locations usually included in Class I as the following:
1. Where volatile flammable liquids or liquefied flammable gases are transferred from one container to another.
2. Interiors of spray booths and areas in the vicinity of spraying and painting operations where volatile flammable solvents are used.
3. Locations containing open tanks or vats of volatile flammable liquids.
4. Drying rooms or compartments for the evaporation of flammable solvents.
5. Locations with fat and oil extraction equipment that uses volatile flammable solvents.
6. Portions of cleaning and dyeing plants where flammable liquids are used.
7. Gas generator rooms and other portions of gas manufacturing plants where flammable gas may escape.
8. Pump rooms for flammable gas or for volatile flammable liquids that are not adequately ventilated.
9. The interiors of refrigerators and freezers where flammable materials are stored in open or easily ruptured containers.
10. All other locations where ignitable concentrations of flammable vapors or gases are likely to occur in the course of normal operations.
NEC Section (C)(2)(1) describes Class II, Division 2 locations classifications. These are listed as:
1. Locations where some combustible dust is normally in the air but where abnormal operations may increase the suspended dust to ignitable or explosive levels.
2. Locations where combustible dust accumulations are normally not concentrated enough to interfere with the operation of electrical equipment unless an “infrequent equipment malfunction” occurs that increases the level of dust suspended in the air.
3. Locations where combustible dust concentrations in or on electrical equipment may be sufficient to limit heat dissipation or that could be ignited by failure or abnormal operation of electrical equipment.
A variety of airborne environmental conditions that require classification are listed in Article 500. Class I covers locations specified in Sections [500.5(B)(1)] and [500.5 (B)(2)] where flammable gases or vapors are present, or could exist in the air in high enough quantities that they could produce explosive or ignitable mixtures. Section [500.5(B)(1) FPN 1] provides examples of locations usually included in Class I as the following:
1. Where volatile flammable liquids or liquefied flammable gases are transferred from one container to another.
2. Interiors of spray booths and areas in the vicinity of spraying and painting operations where volatile flammable solvents are used.
3. Locations containing open tanks or vats of volatile flammable liquids.
4. Drying rooms or compartments for the evaporation of flammable solvents.
5. Locations with fat and oil extraction equipment that uses volatile flammable solvents.
6. Portions of cleaning and dyeing plants where flammable liquids are used.
7. Gas generator rooms and other portions of gas manufacturing plants where flammable gas may escape.
8. Pump rooms for flammable gas or for volatile flammable liquids that are not adequately ventilated.
9. The interiors of refrigerators and freezers where flammable materials are stored in open or easily ruptured containers.
10. All other locations where ignitable concentrations of flammable vapors or gases are likely to occur in the course of normal operations.
SAFETY SWITCHES FOR ELECTRONIC EQUIPMENT BASIC INFORMATION
Fuses are typically installed in safety switches. Separately mounted fused safety switches are typically categorized as general-duty and heavy-duty types.
The general-duty type safety switch is rated at 240 V maximum and is typically used in residential and light commercial and industrial applications. The heavy-duty type safety switch is rated at 600 V maximum and is typically used in commercial and industrial applications.
Safety switches can typically be ordered with neutral assemblies and equipment grounding assemblies. There is currently no listing for safety switches that are to be used specifically with nonlinear loads.
It is recommended that the manufacturer be contacted to determine if oversized neutral assemblies can be installed in safety switches serving nonlinear electronic load equipment without voiding any listing requirements. In addition, the manufacturer should be contacted to determine if an isolated equipment grounding bus can be installed in the safety switch enclosure for those applications that require this grounding configuration.
Whenever fuses are utilized, there is a risk of a single-phasing condition if one fuse on a three phase system blows. Safety switches are generally not stored energy devices, and may not contain auxiliary functions such as undervoltage release or shunt trip attachments that help protect against a single-phasing condition.
This is an important consideration because some three phase electronic load equipment may be susceptible to damage if a single-phase condition persists. Other devices may need to be installed to provide proper single-phasing protection.
Blown fuse indicators
Recommended practice is to use blown fuse indicators for the quick and safe determination of the source of power outage affecting downstream electronic load equipment. Some safety switches and fused circuit breakers contain indicating devices located on the front enclosure that indicate a blown fuse condition. Some fuses contain an indicator light, providing visual indication that a fuse is blown.
Interrupting ratings
Interrupting ratings of new fuses or existing fuses should be evaluated to determine if proper interrupting ratings are applied. Interrupting ratings need to be reevaluated if there are any changes to the power system, such as installing K-factor transformers.
These transformers are typically specified or manufactured with a low impedance (%Z) resulting in a higher available short-circuit current on the secondary. This condition can be a problem especially where low interrupting capacity fuses, such as Class H fuses, are installed (Class H fuses have an interrupting rating of only 10 000 A).
The general-duty type safety switch is rated at 240 V maximum and is typically used in residential and light commercial and industrial applications. The heavy-duty type safety switch is rated at 600 V maximum and is typically used in commercial and industrial applications.
Safety switches can typically be ordered with neutral assemblies and equipment grounding assemblies. There is currently no listing for safety switches that are to be used specifically with nonlinear loads.
It is recommended that the manufacturer be contacted to determine if oversized neutral assemblies can be installed in safety switches serving nonlinear electronic load equipment without voiding any listing requirements. In addition, the manufacturer should be contacted to determine if an isolated equipment grounding bus can be installed in the safety switch enclosure for those applications that require this grounding configuration.
Whenever fuses are utilized, there is a risk of a single-phasing condition if one fuse on a three phase system blows. Safety switches are generally not stored energy devices, and may not contain auxiliary functions such as undervoltage release or shunt trip attachments that help protect against a single-phasing condition.
This is an important consideration because some three phase electronic load equipment may be susceptible to damage if a single-phase condition persists. Other devices may need to be installed to provide proper single-phasing protection.
Blown fuse indicators
Recommended practice is to use blown fuse indicators for the quick and safe determination of the source of power outage affecting downstream electronic load equipment. Some safety switches and fused circuit breakers contain indicating devices located on the front enclosure that indicate a blown fuse condition. Some fuses contain an indicator light, providing visual indication that a fuse is blown.
Interrupting ratings
Interrupting ratings of new fuses or existing fuses should be evaluated to determine if proper interrupting ratings are applied. Interrupting ratings need to be reevaluated if there are any changes to the power system, such as installing K-factor transformers.
These transformers are typically specified or manufactured with a low impedance (%Z) resulting in a higher available short-circuit current on the secondary. This condition can be a problem especially where low interrupting capacity fuses, such as Class H fuses, are installed (Class H fuses have an interrupting rating of only 10 000 A).
WHY WORK PERMITS? - PRINCIPLE BEHIND WORK PERMITS BASIC INFORMATION
Safe systems of work are crucial in work such as the maintenance of chemical plant where the potential risks are high and the careful coordination of activities and precautions is essential to safe working. In this situation and others of similar risk potential, the safe system of work is likely to take the form of a permit to work procedure.
The permit to work procedure is a specialized type of safe system of work for ensuring that potentially very
dangerous work (e.g. entry into process plant and other confined spaces) is done safely. Although it has been developed and refined by he chemical industry, the principles of permit to work procedures are equally applicable to the management of complex risks in other industries.
Its fundamental principle is that certain defined operations are prohibited without the specific permission
of a responsible manager, this permission being only granted once stringent checks have been made to ensure that all necessary precautions have been taken and that it is safe for work to go ahead.
The people doing the work take on responsibility for following and maintaining the safeguards set out in the
permit, which will defi ne the work to be done (no other work being permitted) and the timescale in which it must be carried out.
To be effective, the permit system requires the training needs of those involved to be identified and met, and monitoring procedures to ensure that the system is operating as intended.
Permit systems must adhere to the following eight principles:
1. wherever possible, and especially with routine jobs, hazards should be eliminated so that the work can
be done safely without requiring a permit to work
2. although the Site Manager may delegate the responsibility for the operation of the permit system, the overall responsibility for ensuring safe operation rests with him/her
3. the permit must be recognized as the master instruction which, until it is cancelled, overrides all
other instructions
4. the permit applies to everyone on site, including contractors
5. information given in a permit must be detailed and accurate. It must state:
(a) which plant/equipment has been made safe and the steps by which this has been achieved
(b) what work may be done
(c) the time at which the permit comes into effect
6. the permit remains in force until the work has been completed and the permit is cancelled by the person
who issued it, or by the person nominated by management to take over the responsibility (e.g. at
the end of a shift or during absence)
7. no work other than that specifi ed is authorized. If it is found that the planned work has to be changed,
the existing permit should be cancelled and a new one issued
8. responsibility for the plant must be clearly defined at all stages.
The permit to work procedure is a specialized type of safe system of work for ensuring that potentially very
dangerous work (e.g. entry into process plant and other confined spaces) is done safely. Although it has been developed and refined by he chemical industry, the principles of permit to work procedures are equally applicable to the management of complex risks in other industries.
Its fundamental principle is that certain defined operations are prohibited without the specific permission
of a responsible manager, this permission being only granted once stringent checks have been made to ensure that all necessary precautions have been taken and that it is safe for work to go ahead.
The people doing the work take on responsibility for following and maintaining the safeguards set out in the
permit, which will defi ne the work to be done (no other work being permitted) and the timescale in which it must be carried out.
To be effective, the permit system requires the training needs of those involved to be identified and met, and monitoring procedures to ensure that the system is operating as intended.
Permit systems must adhere to the following eight principles:
1. wherever possible, and especially with routine jobs, hazards should be eliminated so that the work can
be done safely without requiring a permit to work
2. although the Site Manager may delegate the responsibility for the operation of the permit system, the overall responsibility for ensuring safe operation rests with him/her
3. the permit must be recognized as the master instruction which, until it is cancelled, overrides all
other instructions
4. the permit applies to everyone on site, including contractors
5. information given in a permit must be detailed and accurate. It must state:
(a) which plant/equipment has been made safe and the steps by which this has been achieved
(b) what work may be done
(c) the time at which the permit comes into effect
6. the permit remains in force until the work has been completed and the permit is cancelled by the person
who issued it, or by the person nominated by management to take over the responsibility (e.g. at
the end of a shift or during absence)
7. no work other than that specifi ed is authorized. If it is found that the planned work has to be changed,
the existing permit should be cancelled and a new one issued
8. responsibility for the plant must be clearly defined at all stages.
BEST LOCATIONS FOR PANEL BOARDS AND SWITCH BOARDS OF ELECTRONIC EQUIPMENT BASIC TUTORIALS
Where should panel boards be located?
Switchboards and panelboards that support electronic load equipment and related loads should be properly designed and installed. Recommended practice is to use panelboards specifically listed for nonlinear loads if they serve electronic load equipment.
As a minimum, panelboards should be rated for power or lighting applications, and should not be a lighterduty type. Special attention should be given to the location and installation methods used when installing panelboards.
In addition, protective devices shall adequately protect system components, neutral buses should be sized to accommodate increased neutral currents due to harmonic currents from nonlinear electronic load equipment, and equipment ground buses should be sized to accommodate increased numbers of equipment grounding conductors due to the recommended practices of using insulated equipment grounding conductors and dedicated circuits for electronic load equipment.
Surge protective devices may also be installed external to, or internal to, the switchboards or panelboards.
Location
Panelboards that serve electronic load equipment should be placed as near to the electronic load equipment as practicable, and should be bonded to the same ground reference as the electronic load equipment.
Other panelboards located in the same area as the electronic load equipment that serve other loads such as lighting, heating, ventilation, air conditioning, and process cooling equipment should also be bonded to the same ground reference as the electronic load equipment.
Panelboards should be directly mounted to any building steel member in the immediate area of the installation. Isolation of a panelboard from the metallic building structure by an electrically insulating material, as an attempt to prevent flow of high frequency current through the panelboard, is not recommended practice.
The panelboard and metallic building structure, separated by a dielectric material, become capacitively coupled. The capacitive coupling presents a low impedance at high frequency defeating the original purpose.
NFPA 780-1997 requires effective grounding and bonding between objects such as structural building steel and a panelboard located within side-flash distance (approximately 1.8 m (6 ft), horizontally) of each other. Insulation materials, commonly used in an attempt to separate a panelboard from building steel, are rarely capable of withstanding lightningi nduced arcing conditions.
Switchboards and panelboards that support electronic load equipment and related loads should be properly designed and installed. Recommended practice is to use panelboards specifically listed for nonlinear loads if they serve electronic load equipment.
As a minimum, panelboards should be rated for power or lighting applications, and should not be a lighterduty type. Special attention should be given to the location and installation methods used when installing panelboards.
In addition, protective devices shall adequately protect system components, neutral buses should be sized to accommodate increased neutral currents due to harmonic currents from nonlinear electronic load equipment, and equipment ground buses should be sized to accommodate increased numbers of equipment grounding conductors due to the recommended practices of using insulated equipment grounding conductors and dedicated circuits for electronic load equipment.
Surge protective devices may also be installed external to, or internal to, the switchboards or panelboards.
Location
Panelboards that serve electronic load equipment should be placed as near to the electronic load equipment as practicable, and should be bonded to the same ground reference as the electronic load equipment.
Other panelboards located in the same area as the electronic load equipment that serve other loads such as lighting, heating, ventilation, air conditioning, and process cooling equipment should also be bonded to the same ground reference as the electronic load equipment.
Panelboards should be directly mounted to any building steel member in the immediate area of the installation. Isolation of a panelboard from the metallic building structure by an electrically insulating material, as an attempt to prevent flow of high frequency current through the panelboard, is not recommended practice.
The panelboard and metallic building structure, separated by a dielectric material, become capacitively coupled. The capacitive coupling presents a low impedance at high frequency defeating the original purpose.
NFPA 780-1997 requires effective grounding and bonding between objects such as structural building steel and a panelboard located within side-flash distance (approximately 1.8 m (6 ft), horizontally) of each other. Insulation materials, commonly used in an attempt to separate a panelboard from building steel, are rarely capable of withstanding lightningi nduced arcing conditions.
TYPES OF AC GENERATOR ROTORS BASIC INFORMATION AND TUTORIALS
Synchronous AC generators are fitted with one of two different rotor designs depending on their intended rotational speeds.
Round rotors are solid steel cylinders with the field winding inserted in slots milled into the surface or the rotor. They usually have two or four poles. Round rotors can withstand the stresses of high-speed rotation.
Salient-pole rotors have multiple pole pieces (typically six) mounted to the rotor structure, and the field winding is wound around the pole pieces. Because of their more complex construction and larger diameter-to-length ratios, salient-pole rotors cannot withstand the stresses of high-speed rotation.
Electric utility steam-turbine–driven generators designed for 50- or 60-Hz AC output voltage have round rotors with two poles because they can withstand the stresses of speeds of 3000 and 3600 rpm.
Hydroelectric, diesel, and natural-gas engines have far lower shaft speeds than steam turbines, so the generators they drive usually have six or more pole rotors, requirements usually met with more complex salient-pole rotors.
Three-phase AC generators have a winding that is made up of three separate stator windings, each displaced from the other two by 120 electrical degrees. The three windings can either be wye- or delta-connected. The wye connection is more common because it is better suited for direct high-voltage generation.
Round rotors are solid steel cylinders with the field winding inserted in slots milled into the surface or the rotor. They usually have two or four poles. Round rotors can withstand the stresses of high-speed rotation.
Salient-pole rotors have multiple pole pieces (typically six) mounted to the rotor structure, and the field winding is wound around the pole pieces. Because of their more complex construction and larger diameter-to-length ratios, salient-pole rotors cannot withstand the stresses of high-speed rotation.
Electric utility steam-turbine–driven generators designed for 50- or 60-Hz AC output voltage have round rotors with two poles because they can withstand the stresses of speeds of 3000 and 3600 rpm.
Hydroelectric, diesel, and natural-gas engines have far lower shaft speeds than steam turbines, so the generators they drive usually have six or more pole rotors, requirements usually met with more complex salient-pole rotors.
Three-phase AC generators have a winding that is made up of three separate stator windings, each displaced from the other two by 120 electrical degrees. The three windings can either be wye- or delta-connected. The wye connection is more common because it is better suited for direct high-voltage generation.
WORKS REQUIRING PERMITS BASIC INFORMATION AND TUTORIALS
What are the activities/ works that requires work permit?
The main types of permit and the work to be covered by each are identified below. Appendix 6.4 illustrates the essential elements of a permit form with supporting notes on its operation.
General permit
The general permit should be used for work such as:
S alterations to or overhaul of plant or machinery where mechanical, toxic or electrical hazards may arise
S work on or near overhead crane tracks
S work on pipelines with hazardous contents
S work with asbestos-based materials
S work involving ionising radiation
S work at height where there are exceptionally high risks
S excavations to avoid underground services.
Confined space permit
Confined spaces include chambers, tanks (sealed and open-top), vessels, furnaces, ducts, sewers, manholes, pits, flues, excavations, boilers, reactors and ovens.
Many fatal accidents have occurred where inadequate precautions were taken before and during work involving entry into confined spaces. The two main hazards are the potential presence of toxic or other dangerous substances and the absence of adequate oxygen.
In addition, there may be mechanical hazards (entanglement on agitators) and raised temperatures. The work to be carried out may itself be especially hazardous when done in a confined space, for example, cleaning using solvents, cutting/welding work.
Should the person working in a confined space get into difficulties for whatever reason, getting help in and
getting the individual out may prove difficult and dangerous.
Stringent preparation, isolation, air testing and other precautions are therefore essential and experience shows that the use of a confined space entry permit is essential to confirm that all the appropriate precautions
have been taken.
Work on high voltage apparatus (including testing)
Work on high voltage apparatus (over about 600 volts) is potentially high risk. Hazards include:
S possibly fatal electric shock/burns to the people doing the work
S electrical fires/explosions
S consequential danger from disruption of power supply to safety-critical plant and equipment.
In view of the risk, this work must only be done by suitably trained and competent people acting under the terms of a high voltage permit.
Hot work
Hot work is potentially hazardous as a:
S source of ignition in any plant in which highly flammable materials are handled
S cause of fires in all locations, regardless of whether highly flammable materials are present.
Hot work includes cutting, welding, brazing, soldering and any process involving the application of a naked
flame. Drilling and grinding should also be included where a flammable atmosphere is potentially present.
In high risk areas hot work may also involve any equipment or procedure that produces a spark of sufficient energy to ignite highly flammable substances.
Hot work should therefore be done under the terms of a hot work permit, the only exception being where hot work is done in a designated area suitable for the purpose.
The main types of permit and the work to be covered by each are identified below. Appendix 6.4 illustrates the essential elements of a permit form with supporting notes on its operation.
General permit
The general permit should be used for work such as:
S alterations to or overhaul of plant or machinery where mechanical, toxic or electrical hazards may arise
S work on or near overhead crane tracks
S work on pipelines with hazardous contents
S work with asbestos-based materials
S work involving ionising radiation
S work at height where there are exceptionally high risks
S excavations to avoid underground services.
Confined space permit
Confined spaces include chambers, tanks (sealed and open-top), vessels, furnaces, ducts, sewers, manholes, pits, flues, excavations, boilers, reactors and ovens.
Many fatal accidents have occurred where inadequate precautions were taken before and during work involving entry into confined spaces. The two main hazards are the potential presence of toxic or other dangerous substances and the absence of adequate oxygen.
In addition, there may be mechanical hazards (entanglement on agitators) and raised temperatures. The work to be carried out may itself be especially hazardous when done in a confined space, for example, cleaning using solvents, cutting/welding work.
Should the person working in a confined space get into difficulties for whatever reason, getting help in and
getting the individual out may prove difficult and dangerous.
Stringent preparation, isolation, air testing and other precautions are therefore essential and experience shows that the use of a confined space entry permit is essential to confirm that all the appropriate precautions
have been taken.
Work on high voltage apparatus (including testing)
Work on high voltage apparatus (over about 600 volts) is potentially high risk. Hazards include:
S possibly fatal electric shock/burns to the people doing the work
S electrical fires/explosions
S consequential danger from disruption of power supply to safety-critical plant and equipment.
In view of the risk, this work must only be done by suitably trained and competent people acting under the terms of a high voltage permit.
Hot work
Hot work is potentially hazardous as a:
S source of ignition in any plant in which highly flammable materials are handled
S cause of fires in all locations, regardless of whether highly flammable materials are present.
Hot work includes cutting, welding, brazing, soldering and any process involving the application of a naked
flame. Drilling and grinding should also be included where a flammable atmosphere is potentially present.
In high risk areas hot work may also involve any equipment or procedure that produces a spark of sufficient energy to ignite highly flammable substances.
Hot work should therefore be done under the terms of a hot work permit, the only exception being where hot work is done in a designated area suitable for the purpose.
POWER CIRCUIT BREAKER TYPES FOR SAFETY INFORMATION BASICS
The five general types of high-voltage circuit breakers are as follows.
1 Oil circuit breakers use standard transformer oil, an effective medium for quenching the arc and providing an open break after current has dropped to zero. There are two general types of oil circuit breakers: dead-tank for the higher voltage ranges and live-tank for lower voltages.
Oil circuit breakers have been improved by adding such features as oil-tight joints, vents, and separate chambers to prevent the escape of oil.
Also, improved operating mechanisms prevent gas pressure from reclosing the contacts, making them reliable for system voltages up to 362 kV. However, above 230 kV, oil-less breakers are more economical.
2 Air-blast circuit breakers were developed as alternatives to oil circuit breakers as voltages increased. They depend on the good insulating and arc-quenching properties of dry and clean compressed air injected into the contact region.
3 Magnetic-air circuit breakers use a combination of strong magnetic field with a special arc chute to lengthen the arc until the system voltage is unable to maintain the arc any longer. They are used principally in power distribution systems.
4 Gas circuit breakers take advantage of the excellent arc-quenching and insulating properties of sulfur hexafluoride (SF6) gas. These outdoor breakers can interrupt system voltages up to 800 kV.
These circuit breakers are typically included in gasinsulated substations (GISs) that offer space-saving and environmental advantages over conventional outdoor substations. Gas (SF6) circuit breakers are made with ratings up to 800 kV and continuous cur rent up to 4000 A.
They are alternatives to oil and vacuum breakers for metal-clad and metal-enclosed switchgear up to 38 kV.
5 Vacuum circuit breakers, more accurately termed vacuum-bottle interrupters, are generally used for voltages up to 38 kV and continuous current ratings to 3000 A.
They are used for higher system voltage, current, and interrupting ratings, and are typically specified for metal-clad and metal-enclosed switchgear in distribution systems.
1 Oil circuit breakers use standard transformer oil, an effective medium for quenching the arc and providing an open break after current has dropped to zero. There are two general types of oil circuit breakers: dead-tank for the higher voltage ranges and live-tank for lower voltages.
Oil circuit breakers have been improved by adding such features as oil-tight joints, vents, and separate chambers to prevent the escape of oil.
Also, improved operating mechanisms prevent gas pressure from reclosing the contacts, making them reliable for system voltages up to 362 kV. However, above 230 kV, oil-less breakers are more economical.
2 Air-blast circuit breakers were developed as alternatives to oil circuit breakers as voltages increased. They depend on the good insulating and arc-quenching properties of dry and clean compressed air injected into the contact region.
3 Magnetic-air circuit breakers use a combination of strong magnetic field with a special arc chute to lengthen the arc until the system voltage is unable to maintain the arc any longer. They are used principally in power distribution systems.
4 Gas circuit breakers take advantage of the excellent arc-quenching and insulating properties of sulfur hexafluoride (SF6) gas. These outdoor breakers can interrupt system voltages up to 800 kV.
These circuit breakers are typically included in gasinsulated substations (GISs) that offer space-saving and environmental advantages over conventional outdoor substations. Gas (SF6) circuit breakers are made with ratings up to 800 kV and continuous cur rent up to 4000 A.
They are alternatives to oil and vacuum breakers for metal-clad and metal-enclosed switchgear up to 38 kV.
5 Vacuum circuit breakers, more accurately termed vacuum-bottle interrupters, are generally used for voltages up to 38 kV and continuous current ratings to 3000 A.
They are used for higher system voltage, current, and interrupting ratings, and are typically specified for metal-clad and metal-enclosed switchgear in distribution systems.
NEW EMPLOYEE SAFETY ORIENTATION TUTORIALS AND TIPS
For employers with a safety manager, the manager can conduct the classroom part of orientation/training, prepare all the training materials (handouts, forms, checklists, lesson plan, etc.), conduct the employee evaluation, and maintain all documentation. The facility supervisor(s) can conduct the on-the-job training and observation, and determine when the employee is çéady for the evaluation.
For employers or departments without a safety manager, the company safety committee can share responsibilities for conducting the job hazard analyses and the training program. The safety committee can put together the orientation/training materials, conduct the "classroom" training, and keep records. The department where employees will work can conduct the hands-on training.
During the orientation period, introduce new workers to all the basic safety information that applies to their work areas, such as:
• General hazards in the work area;
• Specific hazards involved in each task the employee performs;
• Hazards associated with other areas of the facility;
• Company safety policies and work rules;
• Proper safety practices and procedures to prevent accidents;
• The location of emergency equipment such as fire extinguishers, eyewash stations, first-aid supplies, etc.;
• Smoking regulations and designated smoking areas;
• Emergency evacuation procedures and routes;
• Who to talk to about safety questions, problems, etc.;
• What to do if there is an accident or injury;
• How to report emergencies, accidents, and near misses;
• How to select, use, and care for personal protective equipment;
• Safe housekeeping rules;
• Facility security procedures and systems;
• How to use tools and equipment safely;
• Safe lifting techniques and materials-handling procedures; and
• Safe methods for handling, using, or storing hazardous materials and the location of material safety data sheets.
Orientation programs can be updated and refined by reviewing accident near-miss reports. Near-miss reports offered early warning signs of new or recurrent hazards in the workplace that must be corrected before someone gets hurt or equipment is damaged.
An evaluation of illness and injury reports are also a catalyst for changes in safety orientation and training programs. Orientation can involve several ley els of new employee involvement, from awareness information to formal training programs.
Awareness orientation/training informs employees about a potential hazard in the workplace and their role in responding to the hazard, even though they are not directly exposed to the hazard. For example, "affected" employees can be told about locks and tags for electrical systems without being trained how to implement the lockout/tagout program.
It is useful to rely on a checklist to ensure that appropriate safety orientation is provided to new workers. These checklists should be modified to fit the needs of the organization or site.
For employers or departments without a safety manager, the company safety committee can share responsibilities for conducting the job hazard analyses and the training program. The safety committee can put together the orientation/training materials, conduct the "classroom" training, and keep records. The department where employees will work can conduct the hands-on training.
During the orientation period, introduce new workers to all the basic safety information that applies to their work areas, such as:
• General hazards in the work area;
• Specific hazards involved in each task the employee performs;
• Hazards associated with other areas of the facility;
• Company safety policies and work rules;
• Proper safety practices and procedures to prevent accidents;
• The location of emergency equipment such as fire extinguishers, eyewash stations, first-aid supplies, etc.;
• Smoking regulations and designated smoking areas;
• Emergency evacuation procedures and routes;
• Who to talk to about safety questions, problems, etc.;
• What to do if there is an accident or injury;
• How to report emergencies, accidents, and near misses;
• How to select, use, and care for personal protective equipment;
• Safe housekeeping rules;
• Facility security procedures and systems;
• How to use tools and equipment safely;
• Safe lifting techniques and materials-handling procedures; and
• Safe methods for handling, using, or storing hazardous materials and the location of material safety data sheets.
Orientation programs can be updated and refined by reviewing accident near-miss reports. Near-miss reports offered early warning signs of new or recurrent hazards in the workplace that must be corrected before someone gets hurt or equipment is damaged.
An evaluation of illness and injury reports are also a catalyst for changes in safety orientation and training programs. Orientation can involve several ley els of new employee involvement, from awareness information to formal training programs.
Awareness orientation/training informs employees about a potential hazard in the workplace and their role in responding to the hazard, even though they are not directly exposed to the hazard. For example, "affected" employees can be told about locks and tags for electrical systems without being trained how to implement the lockout/tagout program.
It is useful to rely on a checklist to ensure that appropriate safety orientation is provided to new workers. These checklists should be modified to fit the needs of the organization or site.
RELIABILITY CENTERED MAINTENANCE (RCM)
What is Reliability Centered Maintenance?
Reliability-Centered Maintenance (RCM) is the process of determining the most effective maintenance approach. The RCM philosophy employs Preventive Maintenance (PM), Predictive Maintenance (PdM), Real-time Monitoring (RTM), Run-to-Failure (RTF- also called reactive maintenance) and Proactive Maintenance techniques in an integrated manner to increase the probability that a machine or component will function in the required manner over its design life cycle with a minimum of maintenance.
The goal of the philosophy is to provide the stated function of the facility, with the required reliability and availability at the lowest cost. RCM requires that maintenance decisions be based on maintenance requirements supported by sound, technical, and economic justification.
A Brief History of RCM
RCM originated in the Airline industry in the 1960s. By the late 1950s, the cost of maintenance activities in this industry had become high enough to warrant a special investigation into the effectiveness of those activities. Accordingly, in 1960, a task force was formed consisting of representatives of both the airlines and the Federal Aviation Administration (FAA) to investigate the capabilities of preventive maintenance.
The establishment of this task force subsequently led to the development of a series of guidelines for airlines and aircraft manufacturers to use, when establishing maintenance schedules for their aircraft.
This led to the 747 Maintenance Steering Group (MSG) document MSG-1; Handbook: Maintenance Evaluation and Program Development from the Air Transport Association in 1968. MSG-1 was used to develop the maintenance program for the Boeing 747 aircraft, the first maintenance program to apply RCM concepts. MSG-2, the next revision, was used to develop the maintenance programs for the Lockheed L 1011 and the Douglas DC-10.
The success of this program is demonstrated by comparing maintenance requirements of a DC-8 aircraft, maintained using standard maintenance techniques, and the DC-10 aircraft, maintained using MSG-2 guidelines. The DC-8 aircraft has 339 items that require an overhaul, verses only seven items on a DC-10.
Using another example, the original Boeing 747 required 66,000 labor hours on major structural inspections before a major heavy inspection at 20,000 operating hours. In comparison, the DC-8 - a smaller and less sophisticated aircraft using standard maintenance programs of the day required more than 4 million labor hours before reaching 20,000 operating hours.
In 1974 the U.S. Department of Defense commissioned United Airlines to write a report on the processes used in the civil aviation industry for the development of maintenance programs for aircraft. This report, written by Stan Nowlan and Howard Heap and published in 1978, was entitled Reliability Centered Maintenance,5 and has become the report upon which all subsequent Reliability Centered Maintenance approaches have been based.
What Nowlan and Heap found was that many types of failures could not be prevented no matter how intensive the maintenance activities were. Additionally it was discovered that for many items the probability of failure did not increase with age. Consequently, a maintenance program based on age will have little, if any effect on the failure rate.
Reliability-Centered Maintenance (RCM) is the process of determining the most effective maintenance approach. The RCM philosophy employs Preventive Maintenance (PM), Predictive Maintenance (PdM), Real-time Monitoring (RTM), Run-to-Failure (RTF- also called reactive maintenance) and Proactive Maintenance techniques in an integrated manner to increase the probability that a machine or component will function in the required manner over its design life cycle with a minimum of maintenance.
The goal of the philosophy is to provide the stated function of the facility, with the required reliability and availability at the lowest cost. RCM requires that maintenance decisions be based on maintenance requirements supported by sound, technical, and economic justification.
A Brief History of RCM
RCM originated in the Airline industry in the 1960s. By the late 1950s, the cost of maintenance activities in this industry had become high enough to warrant a special investigation into the effectiveness of those activities. Accordingly, in 1960, a task force was formed consisting of representatives of both the airlines and the Federal Aviation Administration (FAA) to investigate the capabilities of preventive maintenance.
The establishment of this task force subsequently led to the development of a series of guidelines for airlines and aircraft manufacturers to use, when establishing maintenance schedules for their aircraft.
This led to the 747 Maintenance Steering Group (MSG) document MSG-1; Handbook: Maintenance Evaluation and Program Development from the Air Transport Association in 1968. MSG-1 was used to develop the maintenance program for the Boeing 747 aircraft, the first maintenance program to apply RCM concepts. MSG-2, the next revision, was used to develop the maintenance programs for the Lockheed L 1011 and the Douglas DC-10.
The success of this program is demonstrated by comparing maintenance requirements of a DC-8 aircraft, maintained using standard maintenance techniques, and the DC-10 aircraft, maintained using MSG-2 guidelines. The DC-8 aircraft has 339 items that require an overhaul, verses only seven items on a DC-10.
Using another example, the original Boeing 747 required 66,000 labor hours on major structural inspections before a major heavy inspection at 20,000 operating hours. In comparison, the DC-8 - a smaller and less sophisticated aircraft using standard maintenance programs of the day required more than 4 million labor hours before reaching 20,000 operating hours.
In 1974 the U.S. Department of Defense commissioned United Airlines to write a report on the processes used in the civil aviation industry for the development of maintenance programs for aircraft. This report, written by Stan Nowlan and Howard Heap and published in 1978, was entitled Reliability Centered Maintenance,5 and has become the report upon which all subsequent Reliability Centered Maintenance approaches have been based.
What Nowlan and Heap found was that many types of failures could not be prevented no matter how intensive the maintenance activities were. Additionally it was discovered that for many items the probability of failure did not increase with age. Consequently, a maintenance program based on age will have little, if any effect on the failure rate.
THE SAFETY-RELATED CASE FOR ELECTRICAL MAINTENANCE
The relationship between safety and preventive maintenance is not a difficult one to establish. Properly designed equipment that is properly installed is well capable of doing its job when it is new.
As equipment ages however, several factors begin to take their toll on electrical equipment.
● Dust, dirt, and other contaminants collect on equipment causing the equipment to overheat and bearings and other moving parts to bind.
● Vibration causes hardware to loosen. Subsequent operations of equipment can cause joints and equipment to fail explosively.
● Heat and age can cause insulation to fail, resulting in shock hazards to personnel.
● Increased loads, motor starting surges, and power quality issues such as harmonics combine to increase the aging process and set the stage for equipment failure.
Unfortunately, the ultimate failure of unmaintained equipment usually occurs when the equipment is needed the most—during electrical faults. Such failures result in arc and blast events that can and do harm workers in the area.
They also result in significant downtime, loss of equipment, and construction cost incurred in rebuilding the equipment. The only way to ensure that electrical equipment continues to operate in an optimal manner is to maintain it so that it stays in factory-new-operating condition.
Regulatory
As discussed above and in previous chapters, the catastrophic failure of electrical equipment creates severe hazards for personnel working in the area. Recognizing this the
Standard for Electrical Safety in the Workplace (NFPA 70E)3 requires that electrical equipment be properly maintained to minimize the possibility of failure.
Relationship of Improperly Maintained Electrical Equipment to the Hazards of Electricity
Improperly maintained equipment may expose workers to any of the three electrical hazards. For example:
1. Improperly maintained tools or flexible cord sets (extension cords) can have frayed insulation which exposes the energized conductors and allows them to contact the worker or the metallic tool the worker is using. The result is an electric shock.
2. Improperly maintained protective devices, such as circuit breakers or fuses, can fail when interrupting an overcurrent. Such a failure is likely to be explosive; consequently, the worker is exposed to electrical arc and electrical blast.
3. Improperly maintained connections can overheat resulting in any of the following:
a. melted insulation, exposed conductors, and the attendant electrical shock hazard
b. fire
c. failed connections resulting in electrical arc and blast
4. Improperly maintained switchgear, motor control centers, or panelboards can fail explosively when an arc occurs internally. This exposes workers to the effects of electrical blast and possibly electrical arc.
As equipment ages however, several factors begin to take their toll on electrical equipment.
● Dust, dirt, and other contaminants collect on equipment causing the equipment to overheat and bearings and other moving parts to bind.
● Vibration causes hardware to loosen. Subsequent operations of equipment can cause joints and equipment to fail explosively.
● Heat and age can cause insulation to fail, resulting in shock hazards to personnel.
● Increased loads, motor starting surges, and power quality issues such as harmonics combine to increase the aging process and set the stage for equipment failure.
Unfortunately, the ultimate failure of unmaintained equipment usually occurs when the equipment is needed the most—during electrical faults. Such failures result in arc and blast events that can and do harm workers in the area.
They also result in significant downtime, loss of equipment, and construction cost incurred in rebuilding the equipment. The only way to ensure that electrical equipment continues to operate in an optimal manner is to maintain it so that it stays in factory-new-operating condition.
Regulatory
As discussed above and in previous chapters, the catastrophic failure of electrical equipment creates severe hazards for personnel working in the area. Recognizing this the
Standard for Electrical Safety in the Workplace (NFPA 70E)3 requires that electrical equipment be properly maintained to minimize the possibility of failure.
Relationship of Improperly Maintained Electrical Equipment to the Hazards of Electricity
Improperly maintained equipment may expose workers to any of the three electrical hazards. For example:
1. Improperly maintained tools or flexible cord sets (extension cords) can have frayed insulation which exposes the energized conductors and allows them to contact the worker or the metallic tool the worker is using. The result is an electric shock.
2. Improperly maintained protective devices, such as circuit breakers or fuses, can fail when interrupting an overcurrent. Such a failure is likely to be explosive; consequently, the worker is exposed to electrical arc and electrical blast.
3. Improperly maintained connections can overheat resulting in any of the following:
a. melted insulation, exposed conductors, and the attendant electrical shock hazard
b. fire
c. failed connections resulting in electrical arc and blast
4. Improperly maintained switchgear, motor control centers, or panelboards can fail explosively when an arc occurs internally. This exposes workers to the effects of electrical blast and possibly electrical arc.
ELECTRICAL EMERGENCIES GUIDE - WHAT TO DO IN CASE OF ELECTRICAL EMERGENCIES?
Strong winds, ice or unintentional contact with equipment may cause trees or tree limbs to fall into powerlines. This may cause wires to break and fall to the ground. Should this happen, notify the electric utility company immediately.
A fallen wire can create hazards for workers and the general public. Objects touched by a fallen wire - fences, vehicles, buildings or even the surrounding ground - must be considered energized and should not be touched.
It is impossible to tell simply by looking whether a downed wire is energized. Consider all downed wires energized and dangerous until the electric utility personnel notify you otherwise.
Where a power line has fallen across a vehicle, occupants should remain within the vehicle. If they must leave the vehicle because of a life-threatening situation, such as fire or potential explosion, they should jump clear of the vehicle without touching either the vehicle or wire and the ground at the same time.
Once clear of the vehicle, they should shuffle away, taking small steps and keeping both feet in contact with the ground.
Remember, electricity can be transmitted from the victim to you. If a switch is accessible, shut off the power immediately. Otherwise, stand on a dry surface and pull the victim away with a dry board or rope. Do not use your hands or anything metal.
Use a C02 or dry chemical extinguisher to put out an electrical fire. Water should be used only by trained firefighting personnel. In an emergency involving power lines or electrical equipment, call the electric utility company immediately.
Training Workers
Ensure that workers assigned to operate cranes and other boomed vehicles are specifically trained in safe operating procedures. Also ensure that workers are trained (1) to understand the limitations of such devices as boom guards, insulated lines, ground rods, nonconductive links, and proximity warning devices, and (2) to recognize that these devices are not substitutes for de-energizing and grounding lines or maintaining safe clearance.
Workers should also be trained to recognize the hazards and use proper techniques when rescuing coworkers or recovering equipment in contact with electrical energy. CSA guidelines list techniques that can be used when equipment contacts energized power lines [CSA 1982]. All employers and workers should be trained in cardiopulmonary resuscitation (CPR).
A fallen wire can create hazards for workers and the general public. Objects touched by a fallen wire - fences, vehicles, buildings or even the surrounding ground - must be considered energized and should not be touched.
It is impossible to tell simply by looking whether a downed wire is energized. Consider all downed wires energized and dangerous until the electric utility personnel notify you otherwise.
Where a power line has fallen across a vehicle, occupants should remain within the vehicle. If they must leave the vehicle because of a life-threatening situation, such as fire or potential explosion, they should jump clear of the vehicle without touching either the vehicle or wire and the ground at the same time.
Once clear of the vehicle, they should shuffle away, taking small steps and keeping both feet in contact with the ground.
Remember, electricity can be transmitted from the victim to you. If a switch is accessible, shut off the power immediately. Otherwise, stand on a dry surface and pull the victim away with a dry board or rope. Do not use your hands or anything metal.
Use a C02 or dry chemical extinguisher to put out an electrical fire. Water should be used only by trained firefighting personnel. In an emergency involving power lines or electrical equipment, call the electric utility company immediately.
Training Workers
Ensure that workers assigned to operate cranes and other boomed vehicles are specifically trained in safe operating procedures. Also ensure that workers are trained (1) to understand the limitations of such devices as boom guards, insulated lines, ground rods, nonconductive links, and proximity warning devices, and (2) to recognize that these devices are not substitutes for de-energizing and grounding lines or maintaining safe clearance.
Workers should also be trained to recognize the hazards and use proper techniques when rescuing coworkers or recovering equipment in contact with electrical energy. CSA guidelines list techniques that can be used when equipment contacts energized power lines [CSA 1982]. All employers and workers should be trained in cardiopulmonary resuscitation (CPR).
CREATING A CULTURE OF ELECTRICAL SAFETY - AN IMPORTANT ASSET
The design of a safe plant layout is beyond the responsibility of individual employees, but it nevertheless is essential for good power production practices and safe working conditions. Narrow aisles, blind intersections, insufficient overhead space and limited access for equipment repair and maintenance all are detrimental to a safe operating environment.
The National Safety Council in the United States has estimated that work-related accidents in the private sector in 1988 cost industry an average of $15,100 per disabling injury. Based on this figure and the U.S. Bureau of Labor Statistics - which reported that in 1988 private U.S.
Industry, employing 90 million workers, had 6.2 million job-related accidents and injuries was in excess of $93 billion. Approximately, half of this total ($46 billion) was for such visible costs as damaged equipment and materials, production delays, time losses of other workers not involved in the accidents and accident reporting.
Similar statistics have been reported in the United Kingdom (UK) and in the European Community. The statistics support the premise that it is the responsibility of every employer to take a strong, proactive stance to ensure their employees' safety.
Designing for safe work environments also means proper scheduling of work activities. It should not be the operator's or worker's responsibility to determine the proper routing of work in process.
To make this type of decision a workers responsibility unfairly shifts to what is truly management's responsibility directly to the worker. It is management's responsibility to ensure that tight work standards are not only defined for each operating facility, but to ensure that procedures and policies are adopted and enforced.
Establishing fair work standards through work measurement or some similar technique is, without question, a prerogative and a right of management. Establishing and enforcing tight work standards has resulted and will continue to result in operators taking dangerous short cuts while completing tasks.
These short cuts often result in industrial accidents and injuries. By the same token, managers should use standards to ensure a fair day's pay for a fair day's work, but they should not use them as a whip to achieve maximum productivity through coercion.
Pressure placed on employees to meet tight production schedules results in the same type of problems as with tight work standards. Reasonable schedules based on reasonable capacity determinations and work standards eliminate the pressure and work-related stress placed on employees to overproduce because of unsafe short cuts.
Having a corporate culture that promotes and makes safety and environment a priority should be the goal of the industry. Creating a culture of safety first requires site-specific work practices and working environments to be carefully assessed with a focus on identifying high-risk areas, and then developing concrete plans for improved occupational and process safety performance.
Management must focus on using employee insights to prevent costly and potentially deadly accidents before they occur, creating a safer workplace by taking into account both the environment in which employees work and the culture that drives their daily work experience.
As an employer, it is your responsibility to provide a safe work environment for all employees, free from any hazards, and complying with legal and recommended best practices defined in the standards. Health and safety in the workplace is about preventing work-related injury and disease, and designing an environment that promotes well-being for everyone at work.
Knowledge is the key ingredient in providing a safe work environment. If everyone knows the correct procedures, accidents and injuries will be kept to a minimum.
Both employers and employees should:
• Ensure that the way work is done is safe and does not affect employees' health.
• Ensure that tools, equipment and machinery are safe and are kept safe.
• Ensure that ways of storing, transporting or working with dangerous substances is safe and does not damage employees' health.
Employers must:
• Provide employees with the information, instruction and training they need to do their job safely and without
damaging their health.
• Consult with employees about health and safety in the workplace.
• Monitor the work place regularly and keep a record of what is found during these checks.
Policies should be developed in consultation with employees, both with and without disability. It may be necessary to organize support persons or interpreters so that all employees may participate in the consultation.
Occupational Health and Safety (OH&S) procedures must be implemented wherever the work is being conducted, be that in an office, factory, construction site, substation, along transmission line work or home. As an employer, it is your responsibility to ensure all employees have access to information about safety procedures, and for any reasonable adjustments to be made.
It is crucial that new employees be:
• Briefed of all new staff on OH&S policy at induction.
• Be provided training on all safety procedures, including evacuation and other emergency procedures.
• Provided access to information about safety procedures, in appropriate formats.
It is crucial the existing employees:
• Have access to information in appropriate formats.
• Be provided with regular information updates and re-training sessions.
• Be provided access to information about safety procedures.
• Conduct relevant training on any new equipment or machinery.
The National Safety Council in the United States has estimated that work-related accidents in the private sector in 1988 cost industry an average of $15,100 per disabling injury. Based on this figure and the U.S. Bureau of Labor Statistics - which reported that in 1988 private U.S.
Industry, employing 90 million workers, had 6.2 million job-related accidents and injuries was in excess of $93 billion. Approximately, half of this total ($46 billion) was for such visible costs as damaged equipment and materials, production delays, time losses of other workers not involved in the accidents and accident reporting.
Similar statistics have been reported in the United Kingdom (UK) and in the European Community. The statistics support the premise that it is the responsibility of every employer to take a strong, proactive stance to ensure their employees' safety.
Designing for safe work environments also means proper scheduling of work activities. It should not be the operator's or worker's responsibility to determine the proper routing of work in process.
To make this type of decision a workers responsibility unfairly shifts to what is truly management's responsibility directly to the worker. It is management's responsibility to ensure that tight work standards are not only defined for each operating facility, but to ensure that procedures and policies are adopted and enforced.
Establishing fair work standards through work measurement or some similar technique is, without question, a prerogative and a right of management. Establishing and enforcing tight work standards has resulted and will continue to result in operators taking dangerous short cuts while completing tasks.
These short cuts often result in industrial accidents and injuries. By the same token, managers should use standards to ensure a fair day's pay for a fair day's work, but they should not use them as a whip to achieve maximum productivity through coercion.
Pressure placed on employees to meet tight production schedules results in the same type of problems as with tight work standards. Reasonable schedules based on reasonable capacity determinations and work standards eliminate the pressure and work-related stress placed on employees to overproduce because of unsafe short cuts.
Having a corporate culture that promotes and makes safety and environment a priority should be the goal of the industry. Creating a culture of safety first requires site-specific work practices and working environments to be carefully assessed with a focus on identifying high-risk areas, and then developing concrete plans for improved occupational and process safety performance.
Management must focus on using employee insights to prevent costly and potentially deadly accidents before they occur, creating a safer workplace by taking into account both the environment in which employees work and the culture that drives their daily work experience.
As an employer, it is your responsibility to provide a safe work environment for all employees, free from any hazards, and complying with legal and recommended best practices defined in the standards. Health and safety in the workplace is about preventing work-related injury and disease, and designing an environment that promotes well-being for everyone at work.
Knowledge is the key ingredient in providing a safe work environment. If everyone knows the correct procedures, accidents and injuries will be kept to a minimum.
Both employers and employees should:
• Ensure that the way work is done is safe and does not affect employees' health.
• Ensure that tools, equipment and machinery are safe and are kept safe.
• Ensure that ways of storing, transporting or working with dangerous substances is safe and does not damage employees' health.
Employers must:
• Provide employees with the information, instruction and training they need to do their job safely and without
damaging their health.
• Consult with employees about health and safety in the workplace.
• Monitor the work place regularly and keep a record of what is found during these checks.
Policies should be developed in consultation with employees, both with and without disability. It may be necessary to organize support persons or interpreters so that all employees may participate in the consultation.
Occupational Health and Safety (OH&S) procedures must be implemented wherever the work is being conducted, be that in an office, factory, construction site, substation, along transmission line work or home. As an employer, it is your responsibility to ensure all employees have access to information about safety procedures, and for any reasonable adjustments to be made.
It is crucial that new employees be:
• Briefed of all new staff on OH&S policy at induction.
• Be provided training on all safety procedures, including evacuation and other emergency procedures.
• Provided access to information about safety procedures, in appropriate formats.
It is crucial the existing employees:
• Have access to information in appropriate formats.
• Be provided with regular information updates and re-training sessions.
• Be provided access to information about safety procedures.
• Conduct relevant training on any new equipment or machinery.
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