Electrical Practices

DOE-STD-1030-96

example, isolating a pump motor for bearing maintenance should also

include shutting and tagging the pump suction and discharge valves to

prevent possible rotation from fluid flow.

Only controlled drawings, controlled system schematics, or other

controlled documents should be used as references for determining or

verifying isolation points. In the absence of controlled drawings, a

physical walkdown should be performed by a qualified person to ensure

that isolation will be achieved by the planned lockout/tagout.

Operation or removal of tagged-out equipment is NEVER permitted.

Removal of tagged-out equipment would be impossible unless new

isolation boundaries have been established and the tagged-out component

is now itself isolated. In that case, any affected lockout/tagout should be

modified to reflect the new isolation boundaries. The obsolete tag(s)

should be removed in accordance with established procedures before

starting maintenance activities.

Some control devices "seal in" when actuated and could cause equipment

to start when power is restored. Because of this component trait, the

practice of verifying lockout/tagout isolation by operating the controls

(e.g., pressing the start button) for the affected equipment should not be

permitted.

Control switches should be tagged in a position corresponding to the

desired protective state of the equipment (e.g., OFF, neutral, pull-to-

lock), even when another device (e.g., circuit breaker, disconnect

switch, valve in pneumatic supply line) provides the primary isolation

from the energy source.

4.2.3.2 Electrical Practices

If electrical grounding devices are required, the location and sequence

for installation of each device should be specified in the lockout/tagout

procedure.

All electrical grounding devices used in a lockout/tagout should be

tagged out to ensure that the grounds remain in place until the work is