Refrigeration, Leak Testing, And Evacuation - Hussmann HGL-1BS Installation And Service Instructions Manual

other securely taped to one of the return
bends two thirds of the way through the
evaporator circuit. Some "hunting" of
the expansion valve is normal. The valve
should be adjusted so that during the
hunting the greatest difference between
the two probes is 3º to 5ºF.
Remove valve stem cover and turn
valve stem counter-clockwise to decrease
temperature difference between the
probes. To increase temperature differ-
ence of probes, turn the valve stem clock-
wise. With this adjustment, during a por-
tion of the hunting the temperature dif-
ferences between the two probes may be
less than 3ºF, or at times as low as 0ºF.
Make adjustments of no more than
one half turn of the valve stem at a time
and wait for at least fifteen minutes be-
fore rechecking probe temperature and
making further adjustments. Replace
and tighten cover of the valve stem.
REFRIGERATION –
As stated previously, these cases
can be designed for single or multiplexed
installations. The following is a descrip-
tion of a 'packaged system' which in-
cludes the case, a factory-designed con-
densing unit, electrical line set, and refrig-
eration line set. These systems come pre-
charged for easy field installation.
If it should become necessary to
leak test the system, please adhere to the
following notice:
NOTICE: BECAUSE OF THE CFC AT-
MOSPHERIC CONSIDERATIONS
BEING TAKEN TODAY, WE ASK
THAT LEAK TESTING BE DONE WITH
REFRIGERANT 22 MIXED WITH NI-
TROGEN.
IF THE CONDENSING UNIT
NAMEPLATE DESIGNATES A RE-
FRIGERANT OTHER THAN R-22 RE-
MOVE ALL R-22 FROM THE IMMEDI-
ATE AREA TO AVOID CONFUSION
AFTER LEAK TESTING AND EVACU-
ATING THE UNIT. RECHARGE THE
UNIT WITH PROPER REFRIGERANT.
LEAK TESTING –
***** CAUTION*****
The test gas cylinder must be
equipped with a pressure gauge and regu-
lator so that system test pressures do not
exceed maximum allowable limits. Do not
ever use anything other than a R-22 / Ni-
trogen mixture for leak testing.
Attach a refrigerant test gas cylin-
der to your service manifold and connect
the manifold to the charging port on the
liquid line valve. Charge an R-22 / Nitro-
gen mixture into the system, raising the
pressure to the remote unit's nameplate
for the low side and high side pressures.
Using an electronic detector, carefully
check the entire system for leaks. Take
special care to inspect all brazed and flare
connections.
EVACUATION –
After the system is proven leak
tight, thoroughly evacuate the system ac-
cording to the following procedure:
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