Troubleshooting - Repairs; List Of The Most Common Problems - Lennox WA Series Installation, Operating And Maintenance

TROUBLESHOOTING – REPAIRS

8.1 LIST OF THE MOST COMMON PROBLEMS

PROBLEMS – SYMPTOMS
A) THE COMPRESSOR DOES NOT START
- Motor control circuits established,
the compressor does not run
- Low voltage reading on voltmeter
- The system does not start up
Installation - Operation - Maintenance manual (IOM) • AIR COOLED CHILLERS & SPLIT UNITS - 1106-E
PROBABLE CAUSE
- No power supply
- Compressor motor burnt out
- Voltage too low
- Breaker tripped or fuses blown
- No water flow in the evaporator
- Flow switch contacts open
- Anti short cycle relay action
- Faulty control thermostat
- Oil pressure switch tripped
- Antifreeze thermostat or low
pressure safety switch tripped
- Compressor thermal protection relay
tripped
- High pressure safety switch tripped
RECOMMENDED ACTION
- Check main power supply and
switch positions
- Replace
- Contact power company
- Determine the cause.
If the system is in running order, close
the disconnect
- Check condition of fuses
- Measure flow, check the water
pump and water circuitry and filters
- Find the cause of the trip out
- Check circulation of liquid in the
evaporator, and the condition of the
flow switch
- Wait until the anti short cycle time
delay has expired
- Check for proper operation, set
points, contacts
- Check the oil pressure switch and
determine the cause of the trip out
- Check evaporating pressure, the
condition of the antifreeze
thermostat and the low pressure
safety switch
- Check for proper operation of the
relay
- Check the condensing pressure,
and the condition of the high
pressure safety switch
• 34 •