ELECTRICAL TERMINALS
CAUTION: Electric shock hazard. Turn off all power before continuing with following service.
All power electrical terminals should be retightened every six months, as they tend to loosen
in service due to normal heating and cooling of the wire.
OPERATING LIMITS
0 Maximum allowable condenser water pressure is 250 psig.
ature for operating cycle is 90°F (during system
change-
0 Maximum allowable cooler water pressure is 225 psig.
over from heating to cooling cycle).
0 Maximum leaving condenser water temperature is
135”
F.
0 Minimum leaving water temperature from the cooler with-
This corresponds to 340 to 350 psig head pressure.
out freeze protection is 42°F.
0 Maximum allowable water temperature to cooler in a
non-
0
Minimum entering tower condenser water temperature is
operating cycle is 105°F. Maximum entering water
temper-
70°F.
COMPRESSOR OIL LEVEL
The oil level should be watched carefully upon initial startup
and for sometime thereafter.
At the present time, Suniso No.
3GS,
Calumet
R015,
and
Texaco WF32 oils are approved by Copeland for use in these
compressors. The oil level should be maintained at about
one-
third of the sightglass on the compressor body but is accept-
able at any height on the sightglass.
Oil may be added to the
Copeland
compressor through the
oil fill hole in the crankcase. To add oil, isolate the crankcase
and pour or pump in the necessary oil. If the system contains
no refrigerant, no special precautions are necessary other
than keeping the oil clean and dry.
If the system contains a refrigerant charge, close the suc-
tion valve and reduce crankcase pressure to 1 to 2 psig. Stop
the compressor and close the discharge valve.
Add the required amount of oil. During the period the com-
pressor is exposed to the atmosphere, the refrigerant will
generate a vapor pressure, retarding the entrance of con-
taminants. Before resealing the compressor, purge the crank-
case by opening the suction valve slightly for 1 or 2 seconds.
Close the oil port, open the compressor valves and restore
the system to operation.
OIL EQUALIZATION
Some larger models with four compressors (WHR-180 thru
240D) come equipped with oil equalization lines connecting
the crankcase of both compressors in each refrigerant circuit.
This allows the oil to move from one compressor crankcase
to the other during normal operation, and balance between
the two when the compressors are off. This method of equali-
zation prohibits the oil level from dropping below the bottom
level of the sightglass. Some difference in crankcase oil levels
will still exist during unit operation due to compressor internal
pressures.
The oil equalization line contains a manual shutoff valve
for isolating a compressor during service work. The ball valves
are shipped in the closed position with a tag attached stating
“Notice, Valve Shipped In Closed Position. Can Be Open For
Normal Operation.” When valves are closed for compressor
service, make sure they are opened again for unit operation.
For water cooled units, operation with oil equalization lines
closed should be satisfactory for most jobs.
REFRIGERANT SIGHTGLASS AND MOISTURE INDICATOR
The refrigerant sightglasses should be observed period-
ically. (A monthly observation should be adequate.) A clear
glass of liquid indicates that there is adequate refrigerant
charge in the system to insure proper feed through the
ex-
pansion
valve. Bubbling refrigerant in the sightglass indicates
that the system is short of refrigerant charge. Refrigerant gas
flashing in the sightglass could also indicate an excessive
pressure drop in the line, possibly due to a clogged filter-drier
or a restriction elsewhere in the system. An element inside
the sightglass indicates what moisture condition corresponds
to a given element color. If the sightglass does not indicate
a dry condition after about 12 hours of operation, the unit
should be pumped down and the filter-driers changed.
CRANKCASE HEATERS
The compressors are equipped with crankcase heaters. The
20 HP and larger model compressors have heaters inserted
into the crankcase. The function of the heater is to keep the
temperature in the crankcase high enough to prevent refrig-
erant from migrating to the crankcase and condensing in the
oil during off-cycle.
When a system is to be started up initially in cold ambient,
the power to the heaters should be turned on for some time
(at least 12 hours) before the compressor is started. The
crankcase should be up to about 80°F before the system is
started up, to minimize lubrication problems on liquid slug-
ging of compressor on startup.
If the crankcase is cool (below 80°F) and the oil level in
the sightglass is FULL to top, allow more time for oil to warm
before starting the compressor.
Page 44
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