Lennox MCC Series, Инструкция по установке, эксплуатации и обслуживанию

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Installation - Operation - Maintenance manual (IOM) • AIR COOLED CHILLERS & SPLIT UNITS - 1106-E
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8.1 LIST OF THE MOST COMMON PROBLEMS – CONTINUED
PROBLEMS – SYMPTOMS PROBABLE CAUSE RECOMMENDED ACTION
M) SUCTION PRESSURE IS TOO HIGH
- The compressor runs
continuously
- Too much cooling demand on the
evaporator
- Check the system
a) Expansion valve opened to far
a) Adjust superheat and check that
the expansion valve bulb is
correctly fitted in place
- Suction line unusually cold.
Liquid refrigerant returns to
compressor
b) Expansion valve blocked in open
position
b) Repair or replace
N) SUCTION PRESSURE IS TOO LOW
- Bubbles in sightglass - Low refrigerant charge - Repair the leak and add refrigerant
- Excessive pressure drop across the
filter-drier or the solenoid valve
- Filter-drier obstructed - Replace the cartridge
- No refrigerant passing through the
expansion valve
- Expansion valve bulb has lost its
charge.
- Replace the bulb
- Loss of capacity - Expansion valve obstructed - Clean or replace
- Conditioned space too cold
- Control thermostat contacts stuck in
closed position
- Repair or replace
- Compressor short-cycling - Capacity modulation setting too low - Adjust
- Superheat value too high
- Excessive pressure drop in the
evaporator
- Check the external equalizing line
on the expansion valve
- Low pressure drop in the evaporator - Low water flow
- Check water flow. Check the
condition of the filters, look for
obstructions in the chilled water
circuit piping