Carrier 38AU appendix Liquid Line Filter Drier, Field Refrigerant Access Ports

38AU

Liquid Line Filter Drier —

The factory-provided filter drier is specifically designed to operate with Puron→. Replace the filter drier with factory-authorized components only with a filter drier with desiccant made from 100% molecular sieve grade XH-11. Filter drier must be replaced whenever the refrigerant system is opened.

When removing a filter drier, use a tubing cutter to cut the drier from the system. Do not unsweat a filter drier from the system. Heat from unsweating will release moisture and contaminants from drier into system.

Field Refrigerant Access Ports —

Field service access to refrigerant pressures is through the access ports located at the service valves (see Figs 34 and 38). These ports are 1/4-in SAE Flare couplings with Schrader check valves and service caps. Use these ports to admit nitrogen to the field tubing during brazing, to evacuate the tubing and evaporator coil, to admit initial refrigerant charge into the low-side of the system and when checking and adjusting the system refrigerant charge. When service activities are completed, ensure the service caps are in place and secure; check for leaks. If the Schrader check valve must be removed and re-installed, tighten to 2-3 in-lbs (23-34 N-cm).

Factory High-Flow Access Ports —

There are two additional access ports in the system - on the suction tube between the compressor and the suction service valve and on the liquid tube near the liquid service valve (see Figs 35 and 39). These are brass fittings with black plastic caps. The hose connection fittings are standard 1/4-in SAE Male Flare couplings.

The brass fittings are two-piece High Flow valves, with a receptacle base brazed to the tubing and an integral spring-closed check valve core screwed into the base. (See Fig. 31) This check valve is permanently assembled into this core body and cannot be serviced separately; replace the entire core body if necessary. Service tools are available from RCD that allow the replacement of the check valve core without having to recover the entire system refrigerant charge. Apply compressor refrigerant oil to the check valve core’s bottom o-ring. Install the fitting body with 96 ±-10 in-lbs (1085 ±23 N-cm) of torque; do not overtighten.

5/8” HEX

SEAT	CORE
	(Part No. EC39EZ067)

1/2-20 UNF RH

0.596

30°

WASHER
O-RING	1/2" HEX

.47

This surface provides a metal to metal seal when torqued into the seat. Appropriate handling is required to not scratch or dent the surface.

Fig. 31 - CoreMax Access Port Assembly

45°

DEPRESSOR PER ARI 720 +.01/-.035

FROM FACE OF BODY

7/16-20 UNF RH

C08453

34