Table 4-6. Air Conditioner Abnormal Operating Pressures/Temperatures - Troubleshooting. - continued

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Table 4-6. Air Conditioner Abnormal Operating Pressures/Temperatures - Troubleshooting. - continued

TM-55-1905-220-14-8 Landing Craft Utility LCU 1671-1679 NSN 1905-01-009-1056 Manual

Table 4-6. Air Conditioner Abnormal Operating Pressures/Temperatures - Troubleshooting. - continued

TM 55-1905-220-14-8

4-5. GENERAL (Continued).

Table 4-6. Air Conditioner Abnormal Operating Pressures/Temperatures - Troubleshooting (Continued).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

3. High suction pressure.

Step 1. Overfeeding of thermal expansion valve.

Adjust expansion valve. Check installation of thermal bulb.

Step 2. Leaky compressor suction valves.

Pump down, remove cylinder head, examine valve discs and valve seats.

Replace if

necessary.

Step 3. Capacity control system unloading at too high suction pressure.

Adjust capacity control valve to begin unloading at a lower control point.

Step 4. Clogged bronze screen strainer in compressor suction manifold or temporary suction felt

filter not removed after initial operation.

Pump down, remove and clean screen strainer. Remove felt filter after 50 hours of initial

operation. If dirty, clean and replace for another 50 hours.

4. Low suction pressure.

Step 1. Insufficient refrigerant in system.

Add refrigerant.

Step 2. Excessive superheat.

Adjust thermal expansion valve(s) to 8- 10 superheat.

Step 3. Restricted liquid line or compressor suction strainer.

Pump down, remove and clean strainer.

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