INSPECTION - TM-5-4120-393-140172

TM 5-4120-393-14

4-51. Control Relay (K10) (cont)

Tag and remove leads.

Remove socket (8).

INSPECTION

Check that relay and socket are not cracked or broken.

Check that contacts are not corroded, loose, bent, or missing.

Check that wire leads to socket are not damaged, loose, or missing and that they are properly connected. See wiring

TESTING

Using a multimeter set on lowest OHMS scale, chec k continuity.

a. Continuity should be indicated across the following contacts-A to B, 1 to 7, 3 to 9.

b. Continuity should not be indicated across the following contacts-1 to 4, 3 to 6.

c. Apply 208 VAC, 60 HZ across terminals A and B.

d. Continuity should be indicated across contacts-4 to 7, 6 to 9.

e. Continuity should not be indicated across contacts-1 to 4, 3 to 6.

Replace relay if it fails above tests.

Using a multimeter and relay base schematic, check continuity between contacts and terminals of control relay

socket.

INSTALLATION

See tags and wiring diagram, para 4-13, and connect leads to relay socket.

Clip relay hold down springs (7) onto relay socket (8).

Using screwdriver and wrench, secure relay socket (8) and hold down springs (7) with two screws (4), washers (6)

and nuts (5).

Align relay and socket contacts and push relay (3) firmly into socket (8) and hold down springs (7).

Using screwdriver, install cover (2) with eight screws (1).

NOTE

FOLLOW ON MAINTENANCE:

1. Install junction box number two. See para 4-46.

2. Connect power.

4-120