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DIAGNOSIS OF Ale SYSTEM
CONDITION 3
AIR IN SYSTEM
lOW SIDE NORMAL
LOW SIDE
HAND VALVE
CLOSED
LOW SIDE HOSE
CONNECTED
TO
LOW SIDE SERVICE
CONNECTOR
- AMBIENF
. TEMP:
9S<?-
F.
HIGH SIDE NORMAL
HIGH SIDE HOSE
CONNECTED
TO
HIGH SIDE SERVICE
CONNECTOR
'\
I
Complaint
Cooling is not adequate
Condition
1.
Low side gauge reading is constant and does
not
drop.
Pressure
should
drop
until
compressor cycles (thermostat
control)
or
should indicate modulation
(suction control).
2.
High side gauge reading
slightly
high (or
slightly lower especially if large fan used to
substitute ram air). High side gauge reading
should be 185-205 psi at ambient temperature
of 95°F. See chart for
pressures at other
ambient temperatures.
3.
Sight glass free of bubbles or shows only
occasional bubble.
4.
Discharge air from evaporator
only slightly
cool.
Diagnosis
Non-condensables
present
in system.
Air
or
moisture present instead of full refrigerant charge.
Correction
1.
Leak test system.
a.
Leak test
compressor
seal area
very
carefully.
2.
Discharge refrigerant
from system.
3.
Repair leaks as located.
4.
Replace
Receiver-Drier.
Drier
probably
saturated with moisture.
5.
Check compressor oi I level.
6.
Evacuate system using a vacuum pump, with
particular attention to moisture removal from
system.
7.
Charge system with
NEW Refrigerant-12.
8.
Operate system and check performance.
N4-6
.
J
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Troubleshooting
