Carrier 48EZ(N)-A - Manual (Page 38)

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Servicing Systems on Roofs and 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 service that 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 refrigerant 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) drip cloth or tarp. Cover an
approximate 10x10 ft (3x3 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 unit base.
4. Perform required service.
5. Remove and dispose of any oil contaminated material per
local codes.
Liquid Line Filter Drier
This filter drier is specifically designed to operate with Puron. Use
only factory--authorized components. 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.
Puron (R--410A) Refrigerant Charging
Refer to unit information plate and charging chart. Some R--410A
refrigerant cylinders contain a dip tube to allow liquid refrigerant to
flow from cylinder in upright position. For cylinders equipped
with a dip tube, charge Puron units with cylinder in upright
position and a commercial metering device in manifold hose.
Charge refrigerant into suction--line.
TROUBLESHOOTING
Use the Troubleshooting Guides (See Tables 12--14) if problems
occur with these units.
START--UP CHECKLIST
Use Start--Up checklist to ensure proper start--up procedures are
followed.
PURONR (R--410A) QUICK REFERENCE GUIDE
S Puron refrigerant operates at 50--70 percent higher pressures than R--22. Be sure that servicing equipment and replacement
components are designed to operate with Puron
S Puron refrigerant cylinders are rose colored.
S Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
S Puron systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose when
charging into suction line with compressor operating
S Manifold sets should be minimum 700 psig high side and 180 psig low side with 550 psig low--side retard.
S Use hoses with minimum 700 psig service pressure rating.
S Leak detectors should be designed to detect HFC refrigerant.
S Puron, as with other HFCs, is only compatible with POE oils.
S Vacuum pumps will not remove moisture from oil.
S Do not use liquid--line filter driers with rated working pressures less than 600 psig.
S Do not leave Puron suction line filter driers in line longer than 72 hrs.
S Do not install a suction--line filter drier in liquid line.
S POE oils absorb moisture rapidly. Do not expose oil to atmosphere.
S POE oils may cause damage to certain plastics and roofing materials.
S Wrap all filter driers and service valves with wet cloth when brazing.
S A factory approved liquid--line filter drier is required on every unit.
S Do NOT use an R--22 TXV.
S Never open system to atmosphere while it is under a vacuum.
S When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter
driers. Evacuate to 500 microns prior to recharging.
S Do not vent Puron into the atmosphere.
S Observe all warnings, cautions, and bold text.
S All indoor coils must be installed with a hard shutoff Puron TXV metering device.
48E
Z
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A