TM 5-683/NAVFAC MO-116/AFJMAN 32-1083
Figure 12-1. Padlock and multiple lock adapter.
(c) All employees must follow correct lockout
c. Testing for voltage. After the equipment has
been de-energized, tagged and locked out, the cir-
cuit must be tested to confirm that all conductors to
the equipment are de-energized. This test is espe-
cially important on circuits which involve switches
and freed-type breakers in which the blades cannot
be visually checked. Use a volt meter or a volt-ohm-
milliammeter (VOM) as described in paragraph
13-2 to test the de-energized circuit for zero volts.
Before and after testing the affected conductors,
determine that the VOM is operating satisfactorily
by testing the voltage of a source which is known to
be energized. Once these steps are completed, the
equipment is safe to work on.
d. Maintenance grounding. In spite of all precau-
tions, de-energized circuits can be re-energized inad-
vertently. When this occurs, adequate maintenance
or safety grounding is the only protection for person-
nel. For this reason, it is especially important that
Figure 12-2. Typical safety tag.
adequate grounding procedures be established and
rigidlv enforced. The tools used to apply a mainte-
are applied to devices to ensure that their positions
nance ground are primarily special heavy-duty
will not be changed by unauthorized persons as long
clamps which are connected to cables of adequate
as equipment is blinked out and red tagged. These
capacity. These clamps and cable should not be larger
tags must identify the person having the key to the
than necessary because bulkiness and weight hinder
lock and the reason why the circuit is open. They
personnel while connecting them to the conductors,
must also show the time and date of its application.
Chains, small diameter wire or battery clamps
If fuses have been removed to de-energize the equip-
should not be used to apply a maintenance ground
ment, special precautions should be taken to pre-
because they can easily be vaporized in the event of a
vent their unauthorized reinsertion. The following
fault. Prior to application, ground cables should be
general rules should be observed in every lockout
inspected for broken strands in the conductors and
loose connections to the clamp terminals, and clamp
(a) An employee should never give a lock to
mechanisms should be checked for defects. Defective
equipment should be replaced. Maintenance grounds
should be applied on each side of a work point, or at
(b) Maintenance personnel should learn
proper lockout procedures.
each end of a de-energized circuit.