Instruction manual

21
FEEDER TUBE
STUB TUBE
DEFROST
THERMOSTAT
C99029
Fig. 20 -- Defrost Thermostat
TROUBLESHOOTING
Refer to the Cooling and Heating Troubleshooting Chart (Table 7)
for troubleshooting information.
START--UP CHECKLIST
Use the Start--Up Checklist.
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 (2758 kPa), 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 (4826 kPa) high side and 180 psig (1241 kPa) low side with 550 psig (3792 kPa)
low--side retard.
S Use hoses with minimum 700 psig (4826 kPa) 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 (4137 kPa).
S Do not leave Puron suction line filter driers in line longer than 72 hours.
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 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 wa rnings, cautions,andbold text.
50JZ-- A