Evaporator Coil Metering Devices; Refrigerant System Pressure Access Ports - Carrier WeatherMaster Puron 48HC D17 Service And Maintenance Instructions

9. Interior and exterior finned areas must be thoroughly
cleaned.
10. Finned surfaces should remain wet with cleaning solution
for 10 minutes.
11. Ensure surfaces are not allowed to dry before rinsing.
Reapply cleaner as needed to ensure 10 minute saturation
is achieved.
12. Thoroughly rinse all surfaces with low velocity clean
water using downward rinsing motion of water spray noz-
zle. Protect fins from damage from the spray nozzle.

Evaporator Coil Metering Devices

The metering devices are multiple fixed-bore devices (Acu-
trol™) sweated into the horizontal outlet tubes from the liquid
header, located at the entrance to each evaporator coil circuit
path. The metering devices are non-adjustable. Service re-
quires replacing the entire liquid header assembly.
To check for possible blockage of one or more of these meter-
ing devices, disconnect the supply fan contactor (IFC) coil,
then start the compressor and observe the frosting pattern on
the face of the evaporator coil.
A frost pattern should develop uniformly across the face of the
coil starting at each horizontal header tube. Failure to develop
frost at an outlet tube can indicate a plugged or a missing orifice.
SEAT
5/8" HEX
0.47
1. CoreMax is a registered trademark of Fastest, Inc.
1/2-20 UNF RH
0.596
30°
WASHER
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. 14 — CoreMax

Refrigerant System Pressure Access Ports

There are two access ports in the system - on the suction tube
near the compressor and on the discharge tube near the com-
pressor. These are brass fittings with black plastic caps. The
hose connection fittings are standard
couplings.
The brass fittings are two-piece High Flow valves, with a re-
ceptacle base brazed to the tubing and an integral spring-closed
check valve core screwed into the base. See Fig. 14. This
schrader valve is permanently assembled into the core body
and cannot be serviced separately; replace the entire core body
if necessary. Service tools are available from RCD (P920-
0010) that allow the replacement of the schrader valve core
without having to recover the entire system refrigerant charge.
Apply compressor refrigerant oil to the schrader valve core's
bottom O-ring. Install the fitting body with 96 ± 10 in.-lb
(10.85 ± 1.13Nm) of torque; do not over-tighten.
NOTE: The High Flow valve has a black plastic cap with a rubber
o-ring located inside the cap. This rubber o-ring must be in place
in the cap to prevent refrigerant leaks.
EXAMPLE:
Model 48HC*D28
Circuit A (from Fig. 15):
Outdoor Temperature . . . . . . . . . . . . . . . . . . . . . . . 85°F (29°C)
Suction Pressure. . . . . . . . . . . . . . . . . . . . . .125 psig (860 kPa)
Suction Temperature should be . . . . . . . . . . . . . . . 63°F (17°C)
Circuit B (from Fig. 15):
Outdoor Temperature . . . . . . . . . . . . . . . . . . . . . . . 85°F (29°C)
Suction Pressure. . . . . . . . . . . . . . . . . . . . . .120 psig (830 kPa)
Suction Temperature should be . . . . . . . . . . . . . . . 58°F (14°C)
CORE
(Part No. EC39EZ067)
1/2" HEX
O-RING
1 Access Port Assembly
10
1 / -in. SAE male flare
4
45°
DEPRESSOR PER AHRI 720
+.01/-.035
FROM FACE OF BODY
7/16-20 UNF RH