ClimaCool IOM AR2 SERIES - Manual (Page 59)

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®
SERVICE PROCEDURES —
There are several possible causes for system malfunction with
“refrigerant side” head pressure control and these may be difficult
to isolate from each other . As with any form of system trouble-
shooting, it is necessary to know the existing operating temperatures
and pressures before system problems can be determined . Once the
actual malfunction is established, it is easier to pinpoint the cause and
then take suitable corrective action . The following chart lists the most
common malfunctions, the possible causes, and the remedies . Since
the ORI and ORD are hermetic valves and cannot be disassembled
for inspection and/or replacement of parts, they must be replaced if
they become inoperative .
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Head Pressure Control Valve Operation ORI/ORD
57
SERVICE PROCEDURES —
There are several possible causes for system malfunction
with "refrigerant side" head pressure control and these may
be difficult to isolate from each other. As with any form of
system trouble-shooting, it is necessary to know the existing
operating temperatures and pressures before system
problems can be determined. Once the actual malfunction is established, it is easier to pinpoint the cause and then take
suitable corrective action. The following chart lists the most
common malfunctions, the possible causes, and the
remedies. Since the ORI and ORD are hermetic valves and
cannot be disassembled for inspection and/or replacement of
parts, they must be replaced if they become inoperative.
Malfunction – Low Head Pressure
Possible Cause Remedy
1. Insufficient Refrigerant Charge to adequately flood
condenser.
Add refrigerant.
2. Low pressure setting on ORI. Increase setting.
3. ORI fails to close due to foreign material in valve.
Turn adjustment so foreign material passes
through.
If unsuccessful, replace valve.
4. ORI fails to adjust properly. See 3. above.
5. ORD fails to open due to:
a. Less than 20 psi pressure drop across ORD.
b. Internal parts damaged by overheating when
installed.
See below:
a. Check ORI causes/remedies.
b. Replace ORD.
Malfunction – High Head Pressure
Possible Cause Remedy
1. Dirty condenser coil. Clean coil
2. Air on condenser blocked off. Clean area around condenser.
3. Too much refrigerant charge.
Remove charge until proper head pressure is
maintained.
4. Undersized receiver.
Check receiver capacity against refrigerant
required to maintain desired head pressure.
5. Non-condensibles (air) in system. Purge from system.
6. High pressure setting on ORI. Decrease setting.
7. ORI restricted due to inlet strainer being plugged. Open inlet connection to clean strainer.
8.
ORI fails to adjust properly or to open due to foreign
material in valve.
Turn adjustment so foreign material passes
through.
If unsuccessful, replace valve.
9.
Bypassing hot gas when not required due to:
a.
Internal parts of the ORD are damaged by
overheating when installed.
b. If pressure drop across the condenser, associated
piping and ORI exceeds 14 psi under full load
conditions.
See Below:
a.
Replace ORD.
b.
Use ORD with a higher setting.
WARNING: Serious injury could result from an explosion caused by the rapid expansion of trapped liquid refrigerant
subjected to high temperature. ALWAYS OPEN OR VENT THE SYSTEM BEFORE APPLYING HEAT TO REMOVE
SYSTEM COMPONENTS. Break the element charging cap tube on valve dome by hand or with a clean cut tool. DO NOT
use side cutters, which may seal the opening.
INSTALLATION PRECAUTIONS
1. See page 54 for safe working pressures.
2. Do not overcharge — see charge and charging procedures
on pages 54 and 55.
3. Be sure that the piping does not allow liquid refrigerant to
be trapped in sections where hydrostatic pressure can
develop.
4. Be sure that the receiver is large enough to hold the entire
charge during “warm” operation.
5. Do not overheat — see brazing procedures on page 54.
6. “Caution:” on page 53, right column.
7. “Caution:” on page 54, left and right column.
8. “Caution:” on page 55, left column.
Head Pressure Control Valve Operation ORI/ORD
WARNING: Serious injury could result from an explosion caused by the rapid expansion of trapped liquid refrigerant subjected to high
temperature . ALWAYS OPEN OR VENT THE SYSTEM BEFORE APPLYING HEAT TO REMOVE SYSTEM COMPONENTS . Break the
element charging cap tube on valve dome by hand or with a clean cut tool . DO NOT use side cutters, which may seal the opening .
INSTALLATION PRECAUTIONS
1 . See page 54 for safe working pressures .
2 . Do not overcharge — see charge and charging procedures on
pages 54 and 55 .
3 . Be sure that the piping does not allow liquid refrigerant to be
trapped in sections where hydrostatic pressure can develop . 4 .
Be sure that the receiver is large enough to hold the entire charge
during “warm” operation .
5 . Do not overheat — see brazing procedures on page 53 .
6 . “Caution:” on page 53, right column .
7 . “Caution:” on page 54, left and right column .
8 . “Caution:” on page 55, left column .