TM11-6125-256-34
Section IV. REPAIR OF CONTROL BOX ASSEMBLY COMPONENTS
4-11. Inspection
follows
a. Check wiring harness and leads for broken wires,
damaged insulation, and damaged terminals
(1) Using ohmeter ZM-21A/U, check for continuity
b Inspect terminal blocks components (15 through
between terminals A and A, B and B, C and C, D and D,
21 fig. 4-6), terminal board (1) and electrical receptacle
and F and F Limit is 0 1 ohms, maximum There should
connector (11) for damaged or missing parts
metal spacers
c Inspect electrical components (81 through 89) on
subassembly board for damage
(2) Using insulation breakdown test set
d. Check current relay assembly (92) as follows
AN/GSM-6, apply 750 volts ac at 60 Hz for 1 second
between terminals A, B, C, D, and F tied together and
each of the three metal spacers
(1) Check coil assembly (35, fig 4-7) for signs of
overheating. Resistance should be between 62.37 and
63 63 ohms
(3) Using capacitor test set ZM-3( )/U, check
(2) Inspect stationary contacts (28) and movable
capacitance between terminals A and G, B and G, C and
contact (12) for burned areas Replace burned contacts
G, D and G, and F and G Capacitance should be between
0.1076 and 0.1364 microfarad
(3) Compress compression spring (9) to length of
0.375 inch Compression force must be 4.0 to 4.5 pounds
Replace spring if not serviceable
e Check relay (54) for a coil resistance of
(4) Compress compression spring (15) to a length of
approximately 400 ohms The dropout voltage should be
0.375 inch. Compression force must be 1 35 to 1 65
between 1 5 and 9 4 volts dc The pickup voltage should
pounds Replace spring if not serviceable
be approximately 14 5 volts All measurements should be
at an ambient temperature of 77 F (25C)
e Inspect relay and resistor assembly (53 and 54, fig.
f Check resistor (53) for a value of 348 3 to 351 8
4-6) for damaged or loose parts
ohms
4-12. Testing
a. Check capacitors
a Replace all damaged or missing parts for which
as described in paragraph 4-14.
replacement parts are authorized and for which no repair
procedure is given
