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SERVICE
Refrigeration System
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
This system uses R-410A refrigerant, which has higher
pressures than R-22 and other refrigerants. No other
refrigerant may be used in this system. Gauge set, hoses, and
recovery system must be designed to handle R-410A
refrigerant. If unsure about equipment, consult the equipment
manufacturer.
COMPRESSOR OIL
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to
components.
The compressor is in a R-410A refrigerant system and uses a
polyolester (POE) oil. This oil is extremely hygroscopic,
meaning it absorbs water readily. POE oils can absorb
15 times as much water as other oils designed for HCFC and
CFC refrigerants. Avoid exposure of the oil to the atmosphere.
Servicing Systems on Roofs with Synthetic Materials
POE (polyolester) compressor lubricants are known to cause long
term damage to some synthetic roofing materials. Exposure, even
if immediately cleaned up, may cause embrittlement (leading to
cracking) to occur in one year or more. When performing any ser-
vice which may risk exposure of compressor oil to the roof, take
appropriate precautions to protect roofing. Procedures which risk
oil leakage include but are not limited to compressor replacement,
repairing refrigerants leaks, replacing refrigerant components such
as filter drier, pressure switch, metering device, coil, accumulator,
or reversing valve.
Synthetic Roof Precautionary Procedure:
1.
Cover extended roof working area with an impermeable
polyethylene (plastic) drop cloth or tarp. Cover an approxi-
mate 10 x 10 ft (3.3 x 3.3 m) area.
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 lubricant 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 filter drier is specifically designed to operate
with Puron refrigerant. 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 ac-
cess ports located at the service valves (see Fig. 30-37). 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, en-
sure 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 to 3 in.-lb (23 to 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 Fig. 31 and 35).
These are brass fittings with black plastic caps. The hose connec-
tion fittings are standard 1/4-in. SAE Male Flare 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. 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 refrig-
erant oil to the check valve core's bottom o-ring. Install the fit-
ting body with 96 ±10 in.-lb (1085 ±23 N-cm) of torque; do not
over-tighten.
Comfort Alert Diagnostic Module
The Comfort Alert Diagnostic Module (CADM) monitors and an-
alyzes data from the Copeland™
and the thermostat demand. The CADM also provides a 3-minute
anti-recycle time delay to compressor cycling. Each compressor
has a separate CADM module.
The CADM detects causes for electrical and system related fail-
ures without any sensors. Flashing LEDs communicate the Alert
codes to guide service technicians in accurately and quickly trou-
bleshooting the system and determining root cause for the failure.
Inputs to the CADM include 24-vac power, thermostat Y1 or
Y2, compressor contactor coil (common side) and compressor
power leads (from the compressor contactor). See Table 18.
Control of the compressor contactor coil is through a normally-
closed (power on the module) contact between terminals P and C.
Table 18 — Comfort Alert Diagnostic Module Inputs
INPUT
Control Power
Demand
a
Control Common
Cooling
Contractor Coil
Line A
Line B
Line C
NOTE(S):
a. Only applies to 38AUZ.
Communications of status and alert conditions is through three
LEDs located on the top edge of the module housing (see
Fig. 29): POWER (green), ALERT (yellow), and TRIP (red).
1. Third-party trademarks and logos are the property of their respective
owners.
29
1
Scroll three-phase compressor
TERMINAL
VOLTAGE
R
24-v
Y2
24-v
C
24-v
Y
24-v
P
24-v
T1
Line
T2
Line
T3
Line
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