Carrier Container Refrigeration Unit 69NT40-511-14

Ensure power to the unit is OFF and power plug disconnected

Disconnect the suction modulation valve coil wires by unplugging the connector

Test each lead’s resistance to ground using a digital ohmmeter

Inspect wiring for damage if ground short is present

Check coil’s resistance using a digital ohmmeter

Is coil’s resistance below five ohms?

Plug in the connector for the modulation valve

Open the manual liquid line valve

Inspect the refrigeration unit for paint damage

Clean the damaged area to bare metal using a wire brush, emery paper, or equivalent method

Apply zinc-rich primer to the cleaned area

Has the primer dried completely?

Apply finish coat of paint to match original unit color

Ensure no mixing of refrigerants with air for leak testing.

Use R-134a electronic leak detector for finding leaks.

Test joints with soapsuds for large leaks.

System Charging and Leak Checking

Charge the system with refrigerant to build up pressure between 2.1 to 3.5 kg/cm² (30 to 50 psig).

Remove refrigerant cylinder after charging.

Remove the protective guard from lower section of the unit.

Remove all refrigerant using a refrigerant recovery system.

Locate the compressor junction box and remove wiring.

Disconnect wiring from compressor terminals and remove compressor junction box.

Remove bolts from service valve flanges.

Remove compressor plate mounting bolts.

Remove compressor and mounting plate.

Remove high pressure switch (HPS) from compressor and check operation of switch.