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ASTON COMPACT INSTALLATION MANUAL
Should a major problem develop, refer to the following information
for possible causes and corrective steps.
If compressor won’t run:
1. The fuse may be open or the circuit breaker is tripped. Check
electrical circuits and motor windings for shorts or grounds.
Investigate for possible overloading. Replace fuse or reset
circuit breakers after fault is corrected.
2. Supply voltage may be too low. Check it with a volt meter.
3. Control system may be faulty. Check control for correct wiring
of thermostat or aquastat and check the 24 volt transformer for
proper voltage.
4. Wires may be loose or broken. Replace or tighten.
5. The low pressure switch may have tripped due to one or more
of the following:
a)
Heating
1) Plugged heat exchanger on source side
2) Water flow source side - (Low)
3) Water too cold source side
4)
Low
refrigerant
b)
Cooling
1) Plugged heat exchanger on load side
2) Water flow load side - (Low)
3) Water too cold load side
4)
Low
refrigerant
6. The high pressure switch may have tripped due to one or more
of the following:
a)
Heating
1) Plugged heat exchanger on load side
2) Low water flow load side
3) Water too warm load side
b)
Cooling
1) Plugged heat exchanger on source side
2) Low water flow on source side
3) Water too warm source side
7. The compressor overload protection may be open.
8. The internal winding of the compressor motor may be grounded
to the compressor shell. If so, replace the compressor.
9. The compressor winding may be open or shorted. Disconnect
power. Check continuity with ohm meter. If the winding is open,
replace the compressor.
If sufficient cooling or heating is not obtained:
1. Check control for improper location or setting.
2. Check for restriction in water flow.
3. Check refrigerant subcooling and superheat for proper
refrigerant charge and expansion valve operation.
4. The reversing valve may be defective and creating a bypass
of refrigerant. If the unit will not heat, check the reversing
valve coil.
If the unit operation is noisy:
1. Check compressor for loosened mounting bolts. Make sure
compressor is floating free on its isolator mounts. Check for
tubing contact with the compressor or other surfaces. Readjust
it by bending slightly.
2. Check screws on all panels.
3. Check for chattering or humming in the contactor or relays due to
low voltage or a defective holding coil. Replace the component.
4. Check for proper installation of vibration absorbing material
under the unit.
5. Check for abnormally high discharge pressures.
6. Compressor rotation incorrect
Aurora Control System
NOTE:
Refer to the Aurora Base Control Application and
Troubleshooting Guide and the Instruction Guide: Aurora Interface and
Diagnostics (AID) Tool for additional information.
To check the unit control board for proper operation:
1. Disconnect thermostat wires at the control board.
2. Jumper the desired test input (Y1, Y2, W, O or G) to the R
terminal to simulate a thermostat signal.
3. If control functions properly:
• Check for thermostat and field control wiring (use
the diagnostic inputs mode).
4. If control responds improperly:
• Ensure that component being controlled is functioning
(compressor, blower, reversing
valve, etc.).
• Ensure that wiring from control to the component is
functioning (refer to the LED Definition table below and
use the diagnostic outputs mode).
• If steps above check properly, replace unit control.
Refrigerant Systems
To maintain sealed circuit integrity, do not install service gauges
unless unit operation appears abnormal. Compare the change
in temperature on the air side as well as the water side to the
Operating Parameters tables. If the unit’s performance is not
within the ranges listed, and the airflow and water flow are known
to be correct, gauges should then be installed and superheat and
subcooling numbers calculated. If superheat and subcooling are
outside recommended ranges, an adjustment to the refrigerant
charge may be necessary.
NOTE:
Refrigerant tests must be made with hot water generator
turned “OFF”. Verify that air and water flow rates are at proper
levels before servicing the refrigerant circuit.
Troubleshooting
Summary of Contents for Aston Compact Series
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