26
2. Cover area in front of the unit service panel with a
terry cloth shop towel to absorb lubricant spills and
prevent run-offs, and protect drop cloth from tears
caused by tools or components.
3. Place terry cloth shop towel inside unit immediately
under component(s) to be serviced and prevent lubric-
ant run-offs through the louvered openings in the base
pan.
4. Perform required service.
5. Remove and dispose of any oil contaminated material
per local codes.
Liquid Line Filter Drier —
The factory-provided reversible 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 25 and
27). 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).
Outdoor Coil Metering Devices —
The metering devices are multiple fixed–bore devices
(Acutrol
™
) swaged into the horizontal outlet tubes from
the liquid header, located at the entrance to each
evaporator coil circuit path. These are non–adjustable.
Service requires replacing the entire liquid header
assembly.
To check the indoor coil, disconnect the supply fan signal
(A04-A06 direct-drive fans) or contactor (IFC) coil, then
start the circuit in a Cooling Mode (jumper R to Y1 or
Y2) and observe the frosting pattern on the face of the
indoor coil. A frost pattern should develop uniformly
across the face of the indoor coil starting at each tube at
the Acutrol nipple locations.
To check the outdoor coil, disconnect the outdoor fan
motor. Start the circuit in a Heating Mode (jumper R to
W1 or W2) and observe the frost pattern on the face of the
outdoor coil.
Failure to develop frost at an outlet tube can indicate a
plugged or a missing orifice.
Refrigerant System Pressure Access Ports —
There are two access ports in each circuit - on the suction
tube near the compressor and on the discharge tube near
the compressor. These are brass fittings with black plastic
caps. The hose connection fittings are standard 1/4 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. 21.) 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.
1/2-20 UNF RH
30°
0.596
.47
5/8” HEX
SEAT
CORE
WASHER
DEPRESSOR PER ARI 720
+.01/-.035
FROM FACE OF BODY
7/16-20 UNF RH
O-RING
45°
1/2" HEX
This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.
(Part No. EC39EZ067)
C08453
Fig. 21 -- CoreMax Access Port Assembly
38A
U
Q
Summary of Contents for 38AUQ 16 Series
Page 4: ...4 C10675 Fig 2 38AUQ 25 Unit Dimensions 38AUQ...
Page 19: ...19 C10784 Fig 16 38AUQ 16 Charging Chart 38AUQ...
Page 20: ...20 C10785 Fig 17 38AUQ 25 Charging Chart 38AUQ...
Page 21: ...21 C10786 Fig 18 38AUQ 16 Power Schematic 208 230 3 60 shown 38AUQ...
Page 22: ...22 C10787 Fig 19 38AUQ 25 Power Schematic 208 230 3 60 shown 38AUQ...
Page 23: ...23 C10788 Fig 20 38AUQ 16 25 Control Schematic 38AUQ...
Page 41: ...41 C10363 Fig 35 Wind Baffles Fabrication 38AUQ...
Page 42: ...42 C10366 Fig 36 15 Ton Wind Baffle Brackets Fabrication 38AUQ...
Page 44: ...44 RIGHT BACK LEFT FRONT C10368 Fig 38 Wind Baffle Installation 20 Ton Units 38AUQ...
Page 45: ...45 38AUQ...
