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SERVICING SYSTEMS ON ROOFS WITH SYNTHETIC
MATERIALS
POE (polyolester) compressor lubricants are known to
cause long term damage to some synthetic roofing materi-
als. Exposure, even if immediately cleaned up, may cause
embrittlement (leading to cracking) to occur in one year or
more. When performing any service which may risk expo-
sure of compressor oil to the roof, take appropriate precau-
tions to protect roofing. Procedures which risk oil leakage in-
clude but are not limited to compressor replacement, repair-
ing 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 imperme-
able polyethylene (plastic) drop cloth or tarp. Cover
an approximate 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 lubri-
cant run-offs through the louvered openings in the
base pan.
4. Perform required service.
5. Remove and dispose of any oil contaminated mate-
rial per local codes.
LIQUID LINE FILTER DRIER
The factory-provided reversible filter drier is specifically de-
signed to operate with R-410A 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 refriger-
ant 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 Fig. 17-18).
These ports are 1/4 in. SAE Flare couplings with Schrader
check valves and service caps. Use these ports to admit ni-
trogen 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 ad-
justing the system refrigerant charge. When service activi-
ties 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.-lb
(23-34 N-cm).
CHS-180-240-01SI Rev. A
OFM3
Service
Valves
OFM3
Specifications subject to change without notice.
OFM1
OFM2
Fig. 17 — CHS183 Exterior
OFM4
Service
Valves
Fig. 18 — CHS243 Exterior
OFM1
OFM2
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