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2. Clogged filter drier
(indicated by tempera- filter drier core.
ture change in
refrigerant line thru
drier).
3. Incorrect expansion
valve setting.
4. Expansion valve stuck Repair or replace
or obstructed (i.e.,
high superheat and
high water temperature).
5. Low evaporator water
flow.
6. Noncondensibles in
system.
7. Leaky valves in
compressor (i.e.,
operation at
abnormally high suction
and low discharge
pressures).
Symptom
I. Suction pressure too low.
Probable Cause
1. Shortage of refrigerant Find and repair leak;
(i.e., high superheat,
low subcooling).
2. Thermostat set too low Readjust thermostat.
(i.e., low discharge
pressure, low leaving
water temperature).
3. Low water flow.
4. Clogged filter drier.
5. Expansion valve power Repair or replace
assembly has lost
charge.
6. Obstructed expansion Clean or replace valve.
valve (i.e., high
superheat).
CSRA-SVX01A-EN
Troubleshooting
Replace filter drier or
Re-adjust expansion valve.
expansion valve.
Check strainers. Adjust
water flow.
Evacuate and recharge
system.
Replace compressor.
Recommended Action
recharge system.
Check for clogged
strainers and incorrect
balancing valve settings.
Check for frost on filter
drier. Replace if needed.
expansion valve
power head assembly.
Symptom
J. Suction pressure too high.
Probable Cause
1. Excessive cooling load See Symptom E.
(i.e., high supply
water temperatures).
2. Expansion valve over- Adjust superheat setting;
feeding (i.e. super-heat verify that remote bulb is
too low, liquid flooding properly attached to
to compressor).
3. Suction valves broken Replace compressor.
(i.e., noisy compressor).
Symptom
K. Discharge pressure too low.
Probable CauseRecommended Action
1. Shortage of refrigerant Find and repair leak;
(i.e., low subcooling,
high superheat, bubbles
in sight glass).
2. Broken or leaky
compressor discharge
valves.
3. Defective low pressure Replace defective control.
switch.
4. Unit running below
minimum operating
ambient.
Symptom
L. Discharge pressure too high.
Probable Cause
1. Too little or too warm
condenser air; airflow
restricted.
2. Air or noncondensibles Evacuate and recharge
gas in system (i.e.,
exceptionally hot
condenser).
(Continued on next page)
Recommended Action
suction line.
recharge system.
Replace compressor.
Provide adequate head
pressure controls, or an
ambient lockout switch.
Recommended Action
Clean coil; check fans and
motors for proper function.
system.
63
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