Replacement of Fuses

TM 11-5895-833-12/NAVELEX 0967-LP-550-1010/TO 31R5-2TSC54-91

Sequence

Item to be

number

inspected

Procedure

Reference

Exterior surfaces

Clean the exterior surface of the equipment.

Pars 4-8

Installation

Check to see that the equipment is properly installed.

Connectors and binding poets

Check the tightness of all power connectors and bind-

ing posts.

Grounding system

Check to see that the grounding system is properly in-

stalled. Tighten any loose ground connections.

Signal cables and wires

Inspect cables for fraying or damaged insulation. In-

spect for defective connections with strained wires.

Tighten any loose plugs and connections.

Hardware

Check the condition of all cable assemblies and insure

that all connector pins are not damaged. Make sure

that all threaded hardware is not nicked, burred, or

otherwise marred.

Controls and indicators

Observe that the mechanical acti on of each knob, dial

Tables 3-1 through 3-7

and switch is smooth and free from external or inter-

nal binding and that no excessive looseness exists.

Operation

Operate the equipment according to appropriate in-

Pars 3-4 through 3-15.

structions. Report any operational failure of equip-

ment. Replace defective items for which running

spares are authorized.

is placed in the cap, and the combination is inserted in

4-8. Cleaning

the holder. The removal and insertion procedure is

Inspect the exterior of the equipment. The exterior

similar to that used with a bayonet-type auto-mobile

surfaces should be clean, and free of dust, dirt, grease

lamps.

and fungus.

a. Remove dust and loose dirt with a clean, soft cloth.

CAUTION

Never replace a fuse with one of a higher cur-

WARNING

rent rating. Fuse ratings are normally marked

The fumes of trxchloroethane are toxic. Pro-

on, or adjacent to, each fuseholder and each

vide thorough ventilation whenever used. Do

rating has been carefully chosen to protect the

not use near an open flame. Trichloroethane is

equipment. A fuse of higher current rating will

not flammable, but exposure of fumes to an

remove this protection and endanger the

open flame or hot metal surface forms highly

equipment.

toxic phosgene gas.

b. Remove grease, fungus, and ground-in dirt from the

4-10. Replacement of Indicator Lamps

Two types of indicators are used in the frequency con-

equipment cabinet. Use a cloth dampened (not wet) with

version subsystem; a jewel and lamp assembly. Re-

trichloroethane.

c. Remove dust or dirt from plugs and terminal boards

place the lamp in the jewel and lamp assembly as fol-

lows:

with a brush.

a. Unscrew jewel (because of snug fit, lamp remains

CAUTION

in jewel assembly).

Do not press on any meter face (glass) when

b. Grasp lamp at base and pull from jewel housing.

cleaning; the meter may become damaged.

Discard lamp.

d. Clean the front panel meters and control knobs with

c. Press new lamp into jewel and screw jewel into

a soft, clean cloth. If dirt is difficult to remove, dampen

socket until hand-tight.

the cloth with water; mild soap may be used for more

effective cleaning.

4-11. Monthly Maintenance

e. If available, dry compressed air may be used to re-

Perform the maintenance functions indicated in the

move dust from inaccessible places. However, be careful

organizational monthly preventive maintenance checks

not to exceed a line pressure of 60 pounds per square

and services chart (para 4-12) once each month. A

inch (psi) or mechanical damage from the air-blast may

month is defined as approximately 30 calendar days of

result.

8-hour-per-day operation. If the equipment is operated

16 hours a day, the monthly preventive maintenance

4-9. Replacement of Fuses

checks and services should be performed at 15-day

Both indicating and nonindicating extractor-type fuses

intervals. Adjustment of the maintenance interval must

are used in the AN/TSC-54 frequency conversion

be made to compensate for any unusual

subsystem. Fuses in extractor-type holders are re-leased

by pushing in and turning the holder caps. In each case,

the fuse and cap are then removed together, a new fuse

4-2