Carrier 19QA - Manual (Page 9)

OPERATION
Evacuation — To minimize refrigerant loss, air must
not be allowed to mix with the refrigerant vapor. All spaces
that could contain refrigerant (such as chillers, storage tanks,
and refrigerant hoses) must be completely evacuated before
charging the RMS with refrigerant.
To evacuate air from the storage tank or chiller, connect
the suction service valve of the pump to a vapor valve on
the storage tank or chiller using the shortest possible 1/2-in.
diameter refrigerant hose. Use of hoses or fittings smaller
than 1/2 in. diameter will greatly increase the time required
to pull a complete vacuum of 29 in. Hg (25 mm Hg abso­
lute). Refer to Table 5 for additional information. See
Fig. 9.
Once the connections are made, turn on the pump and
discharge the air into the atmosphere.
■ — Tank Size — 20 cu ft (.57 cu meters)
Typical 400 Ton Chiller
NOTE: A 29 in. Hg vacuum (25 mm Hg absolute) may be obtained
at a rate of approximateiy 1 minute per cu ft of volume.
Fig. 9 — Evacuation of Chiller and Storage Tank
Liquid Refrigerant Transfer
A CAUTION
To prevent release of refrigerant from the dual relief
valve assembly due to expansion, the storage tank must
not be filled above 90% full at 90 F (32 C).
The storage tank is 90% full when the level gage is read­
ing 100%. See Fig. 7.
BEFORE TRANSFERRING LIQUID REFRIGERANT -
Before using the pump for liquid or vapor transfer, run the
pump using air only for approximately 15 minutes. Run­
ning the pump on air will allow it to achieve a normal op­
erating temperature of 120 F (49 C). If refrigerant is used
when the pump is cold, excessive amounts of refrigerant
will be absorbed into the oil, causing dilution of the oil.
This condition may cause oil loss and shorten the life of the
pump.
A WARNING
Do not connect the pump suction service valve directly
to a liquid refrigerant source. Liquid refrigerant will
cause damage to the pump.
Use the same process when transferring liquid refrigerant
from the chiller to the storage tank or from the storage tank
to the chiller. Completely evacuate any vessel that will have
refrigerant transferred to it.
A WARNING
Do not transfer liquid refrigerant into an evacuated chiller
that contains water in the cooler tubes. Freezing water
will cause the cooler tubes to rupture.
NOTE: Make sure the ball valve and coupler assembly are
connected to all refrigerant hoses.
Prior to transferring liquid refrigerant from the storage
vessel to the chiller, make sure all water is completely drained
from the cooler tubes or raise the chiller pressure by using
refrigerant gas (24 in. Hg [ — 81 kPa] for CFC-113,
18 in. Hg [-61 kPa] for HCFC-123, and 15 in. Hg
[-51 kPa] for CFC-11).
TO TRANSFER LIQUID REFRIGERANT
Storage Tank to Chiller — To transfer liquid refrigerant from
the storage tank to the chiller, connect a 6-ft refrigerant hose
from the liquid valve on the storage tank to the chiller charg­
ing valve. Install the liquid indicator on the refrigerant hose.
See Fig. 10. Connect a 12-ft refrigerant hose to the vapor
service valve on the chiller and the suction service valve on
the pump. Copper tubing is factory installed from the pump
to the oil separator. Connect another 6-ft refrigerant hose
from the discharge connection on the oil separator to the
vapor valve on the storage tank. Open the liquid valve on
the storage tank, the charging valve on the chiller, and the
two interconnecting hose valves.
Once liquid refrigerant enters the chiller, open the chiller
vapor valve, the storage tank vapor valve, all valves be­
tween the chiller vapor valve and the storage tank vapor
valve. Turn on the pump. The pump will remove refriger­
ant gas from the chiller and discharge it into the storage
tank. This will create a pressure differential between the
chiller and the storage tank and provide the specified flow
rate.
The end of the liquid refrigerant transfer can be deter­
mined by observing the liquid indicator. When liquid is no
longer visible, the transfer is complete. Close the liquid valve
on the chiller and turn off the pump.
Chiller to Storage Tank — To transfer liquid refrigerant from
the chiller to the storage tank, connect a 6-ft refrigerant hose
from the storage tank liquid valve to the chiller charging
valve. Install the liquid indicator to determine when liquid
transfer is complete. Connect a 12-ft refrigerant hose to the
vapor service valve on the chiller and the suction service
valve on the pump. Copper tubing is factory installed from
the pump to the oil separator. Connect another 6-ft refrig­
erant hose from the discharge connection on the oil sepa­
rator to the vapor valve on the chiller. Open the charging
valve on the chiller, the liquid valve on the storage tank,
and the two interconnecting hose valves.
Once liquid refrigerant enters the storage tank, open the
storage tank vapor valve, chiller vapor valve, and all valves
between the storage tank vapor valve and chiller vapor valve.
Turn on the pump. The pump will remove refrigerant gas
from the storage tank and discharge it into the chiller. This
will create a pressure differential between the storage tank
and provide the specified flow rate.
The end of the liquid refrigerant transfer can be deter­
mined by observing the liquid indicator. When liquid is no
longer visible, the transfer is complete. Close the bottom
valve on the chiller and turn off the pump.