TM 55-4920-404-30&P
ELECTRICAL
Section IV.
the power wires, remove the nut holding the conduit
3-4. ELECTRICAL REPAIRS AND REPLACE-
connector to the fixture and remove the screws and
MENTS. Electrical repairs and replacements re-
washers securing the fixture to the ceiling. Feed
quired on SPAM shelters is covered in TM 10-5410-
power wires through the end of the new fixture and
224-14. Electrical repairs and replacements on the
secure to the ceiling with screws and washers. In-
S-280 shelter is as follows:
stall conduit connector nut, connect power wires, in-
stall fixture cover, lamp, lamp protector and re-
taining straps. Turn circuit breaker back on and
All electrical repairs or replacement
insure the new fixture is operating properly.
should be performed with electrical
power disconnected by an aircraft
c. Power Inlet Panel.
electrician or other qualified person.
(1) Inspect the power inlet panel for loose
a. Shelter Power Cable. Maintenance pro-
ground stud, corroded power inlet connector and
cedures is as follows.
damage electrical outlet cover and connector. Re-
place the power inlet connector by first de-ener-
(1) The shelter power cable should be care-
gizing and removing shelter power cable. Next re-
fully inspected for breaks in the jacket insulation
move screws and power inlet box cover. Remove four
and corrosion of the electrical contacts.
bolts, washers and nuts which hold connector to
(2) The connectors may be replaced using a
panel and, using a standard blade screwdriver,
standard blade screwdriver to remove the connector
loosen contact screws and remove wires from con-
covers and loosen the screws holding the wires in
tacts.
the contacts. Be sure to insert the wires in the same
NOTE
contact on the new connector that they were
installed in on the old connector. Connectors should
Be sure to note which wires are con-
be wired in accordance with instructions given in
nected to which number contact. Refer
drawing 4920-EG-058, figure D-2.
to the shelter wiring diagram in draw-
ing 4920-EG-056, figure D-1, for assis-
tance. Install the new receptacle by in-
serting and securing the wires first.
If connectors are improperly wired, a
Then install the mounting hardware
serious electrical shock hazard may
and reinstall the power inlet panel
result.
cover.
(3) Following repairs or replacement of parts
(2) The ground stud may be replaced by de-en-
to the shelter power cable, it should be checked with
ergizing the shelter, removing the ground stake
an ohmeter for proper connections between con-
wire and removing the power inlet box cover as pre-
nectors and to insure there are no shorts between
viously described.
contacts.
NOTE
NOTE
As an extra safety precaution, remove
The ground contact is bonded to the
the shelter power cable from the power
connector case.
inlet connector.
b. Light Fixtures. Light fixtures should be in-
(3) Loosen the nut securing the stud and re-
spected for broken lamp contacts or other damage.
move the damaged stud. Install a new ground stud,
The lamp and protector may be replaced by re-
secure the inside ground wire, and tighten the
moving the screws holding the retaining straps to
mounting nut. Replace the power box cover, fasten
the light fixture. To replace the light fixture assem-
the ground stake wire outside, and reconnect the
bly, first turn off the 20 amp circuit breaker that
shelter power cable.
supplies power to the lights in the circuit breaker
panel. Using a trouble light to illuminate the shel-
(4) Replacement of the weatherproof outlet
ter, remove the lamp and protector as previously de-
cover should be preceded by turning off the circuit
scribed. Remove the cover of the fixture, disconnect
breaker supplying power to the outlet. Remove the
1978--765117/374
U.S. GOVERNMENT PRINTING OFFICE:
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