RELAY K4 INSPECTION, TESTING, AND REPLACEMENT

TM 9-4120-428-14

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UNIT MAINTENANCE

AIR CONDITIONER, HORIZONTAL, COMPACT

(NSN 4120-01-502-1319)

RELAY K4 INSPECTION, TESTING, AND REPLACEMENT

INITIAL SETUP:

Tools

Materials/Parts

Refrigeration Unit Service Tool Kit, WP 0000 00, Item

Relay

Self-locking nuts (3)

Power Supply, WP 0000 00, Item 6

Equipment Condition

Remove Junction Box (WP 0036 00)

7 11 6

RELAY DIAGRAM

INSPECTION

Check the relay for general condition, evidence of overheating, and loose, broken, or missing terminals.

TESTING

1. Apply +28 VDC to terminal TB1-6 and 28 VDC to terminal TB1-4.

NOTE

Terminals 10 and 8 are not used in single-phase units

2. Check continuity across terminals 1 and 3, 5 and 11, and 10 and 8.

3. Check the multimeter. It should indicate that terminals 1 and 3, 5 and 11, and 10 and 8 are closed. Terminals 1 and

4, 5 and 6, and 10 and 7 are open.

4. Remove 28 VDC power. The Multimeter should indicate that terminals 1 and 4, 5 and 6, and 10 and 7 are closed and

that terminals 1 and 3, 5 and 11, and 10 and 8 are open.

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