An energy control program is a procedure for the proper control of hazardous energy sources. It should include a listing of company-approved steps for the proper and safe ener- gizing and de-energizing of energy isolation devices as well as general company policy statements on policies with respect to preferred methods of operation. Energy control pro- grams fall into two categories—general and specific.
General Energy Control Programs
Overview. A general energy program is one that is inherently generic in nature. Its steps are broad-based and designed in such a way that the program can be used as a procedure for a wide variety of equipment types. General energy control programs should be used only when the equipment being isolated meets all the following criteria:
● The equipment can be disabled, so it has no potential for the release of stored or residual
energy after shutdown.
● The equipment is supplied from a single energy source which can be readily identified and isolated.
● The equipment is completely de-energized and deactivated by the isolation and lock-
ing out procedure.
● No employees are allowed to work on or near the equipment until it has been tagged and locked. (See the tagout-lockout section later in this chapter.)
● A single lockout device will achieve a locked-out condition.
● The isolating circuit breakers or switches are under the exclusive control of the employee(s)
who placed the lock and tag.
● De-energizing and working on the equipment does not create a hazard for other employees.
● There have been no accidents involving unexpected activation or reenergization of the
equipment during previous servicing.
Specific Energy Control Programs
When a part of the system or piece of equipment does not meet all the criteria laid out in the overview to this section, a specific energy control program should be written. Although the procedures will vary depending on the specifics of the installation, at a minimum the program should include the following information:
● The description of the system and/or equipment that will be de-energized.
● Any controls, such as motor starter pushbuttons, that exist on the equipment.
● The voltages and short circuit capacities of the parts of the system which will be de-energized.
● The circuit breakers, switches, or contactors which are used to de-energize the system. ● The steps that must be used to de-energize the system. The steps should include:
1. The methods and order of operation of the circuit breakers, switches, and so on. 2. Any special requirements for the lockout-tagout procedure.
3. Special notifications and safety requirements.
● Reenergizing requirements and procedures.
Basic Energy Control Rules
● The safest and securest method to protect personnel from the electrical hazard is to de- energize the conductors which they must work on or near. De-energization is the preferred method.
● If conductors cannot be de-energized, safety equipment and safety-related work prac-
tices must be used to protect personnel exposed to the energized conductors.
● Before personnel are allowed to work on or near any exposed, de-energized conductors, the circuit breakers and/or disconnect switches must be locked and tagged to prevent their inadvertent operation.
● All personnel should be instructed to never operate or attempt to operate any circuit
breaker and/or disconnect switch when it is tagged and/or locked.
● Only authorized, qualified, and trained personnel should be allowed to operate electric equipment.
● Locks and tags should be removed only by the personnel that placed them. Two excep-
tions may apply under the following situations:
1. If the worker who placed the lock and tag is not available, his or her lock and tag may
be removed by a qualified person who is authorized to perform such an action. This procedure is often called bypassing control as the person who removes the lock and tag is, in fact, bypassing the authority (control) of the person whose tag is being removed.
2. Some facilities may authorize the concept of a group lock. A group lock is placed by an
authorized shift worker, such as the shift operator, and may be removed by another authorized shift worker. This activity should not be used to prevent any employee from placing his or her tag and lock on energy-isolating devices that may feed conductors which they must work on or near.
De-energizing Equipment. The general energy program for de-energizing equipment should include the following steps:
1. Before beginning the process, carefully identify the voltage levels and short circuit
capabilities of the portion of the system which will be de-energized. This information serves to establish the level of the hazard to all personnel.
2. Notify all employees who will be affected by the de-energization that the system is to
be de-energized.
3. Perform necessary checks and inspections to ensure that de-energizing the equipment
will not introduce additional safety hazards, for example, de-energizing safety-related ventilation systems.
4. Shut down all processes being fed by the electric system which is to be de-energized. 5. Open the appropriate circuit breaker and/or switch.
6. Rack the circuit breaker away from the bus if it is of the type that can be manipulated
in this manner.
7. Release stored energy from springs, hydraulic systems, or pneumatics.
8. Discharge and ground any capacitors located in the de-energized portions of the system. 9. Apply tags and/or locks.
10. Attempt to operate the breaker and/or switch to make certain that the locks are pre-
venting operation. If a motor starter is involved, press the start button to make certain the motor will not start.
11. Measure the voltage on the conductors to which employees at the point where they will
be exposed.
12. Notify personnel that the system is safely de-energized, locked, and tagged.
Reenergizing Equipment. Reenergization of some systems is more hazardous than de- energization. While the equipment has been out of service, personnel have grown used to its de-energized voltage status. In addition, tools and/or other equipment may have been inad- vertently left on or near exposed conductors.
Because of these factors, the same type of rigorous steps should be followed during reenergization.
1. All personnel should be notified that the system is to be reenergized and warned to stay
clear of circuits and equipment.
2. A trained, qualified person should conduct all tests and visual inspections necessary to ver-
ify that all tools, electric jumpers, shorts, grounds, and other such devices have been removed and that the circuits are ready to be reenergized.
3. Close and secure all cabinet doors and other safety-related enclosures.
4. Because the tests and inspections may have required some time, the personnel warnings
should be repeated.
5. Locks and tags should be removed by the personnel that placed them.
6. If breakers were racked into disconnected positions, they should be racked in the con-
nected position.
7. Make final checks and tests, and issue final warnings to all personnel.
8. Reenergize the system by closing and reconnecting breakers and switches. These opera-
tions are normally carried out in the reverse order of how they were opened.
Procedures Involving More than One Person. When more than one person is required to lock and tag equipment, each person will place his or her own personal lock and tag on the circuit breakers and/or switches. The placement of multiple locks and tags on equipment is often called ganging. Since few circuit breakers or switches have the ability to accept mul- tiple locks and tags, this procedure can take one of two common approaches.
1. A multiple-lock hasp may be applied to the breaker or switch. Such hasps will accept up
to six locks. If more than six locks are required, multiple-lock hasps may be cascaded. See Fig. 2.55 for examples of such hasps.
2. A lockbox may be used. In such an operation, the lock is applied to the breaker or switch
and the key is then placed inside the lockbox. The lockbox is then secured by the use of a multiple-lock hasp. This approach is used when the presence of many locks on the switch or breaker might cause operational problems.
After the work has been completed, each employee removes his or her lock from the lockbox. The key for the lock is retrieved and the lock can them be removed.