Table of Contents
Advertisement
13 - CONTROL AND ANALYSIS OF BREAKDOWNS
Symptom
Evaporation pressure very high in relation
with the air or water inlet
Very low condensation pressure
Condensation pressure very high in
relation to the air or water outlet, high
pressure pressostat cut-off
Evaporation pressure too low (low
pressostat cut-off )
Compressor does not start, does not make
noise (humming)
Compressor does not start, motor sounds
intermittently
Repeated compressor starts and stops
The compressor makes a noise
Noisy operation
Cycle reversing is not carried out:
- No defrosting
- Does not change winter - summer cycles
Cause
a) Charge excess
b) High water temperature
c) Compressor suction not air tight
d) Cycle reversing valve in middle position
a) Gas lack
b) Low water temperature
c) Compressor suction not air tight
d) Cycle inversion valve in middle position
e) Liquid circuit plugging
a) Air or water fl ow insuffi cient
b) Air or water inlet temperature very high
c) Dirty condenser (does not exchange)
d) Much refrigerant load (fl ooded condenser)
e) The condenser fan is broken down
f) Air in the cooling circuit
a) Low fl ow in evaporator. Air recirculation
b) Frozen evaporator
c) Liquid line as diff erent temperatures at fi lter
inlet and outlet
d) Gas lack
e) Very low condensation pressure
f) Evaporator fan broken down
a) No power
b) The contacts of a control element are open
c) Timing of anti cycle short does not allow the
starting
d) Open contact
e) Contactor coil burnt
f) Indoor Klixon open
a) Electrical power supply very low
b) Power cable disconnected
a) Because of high pressure
b) Control diff erential too short (short cycle)
c) Insuffi cient gas, cut-off because of low
pressure
d) Dirty or frosted evaporator
e) The evaporator fan does not work, cuts off
the low pressostat
f) Expansion valve damaged or clogged by
impurities (cuts off low pressostat)
g) Dehydrating fi lter clogged (cuts off low
safety)
a) Loose attachment
b) Oil lack
c) Compressor noise
a) Unit installed without antivibration protection
a) Electrical fault
b) Inversion valve coil defective
c) Defrost method not working
d) Cycle inversion valve in middle position
e) Control fault
Solution
a) Collect refrigerant
b) Verify overheating
c) Verify compressor state and replace
d) Check that the valve is not clogged. Replace
if necessary
a) Search for leaks, complete charge
b) Wait for regular speed
c) Verify compressor state and replace
d) Check that the valve is not clogged. Replace
if necessary
e) Verify the dehydrating fi lter and expansion
valve
a) Verify the air or water circuits (fl ow, fi lter
cleanliness etc.)
b) Verify the control thermostat readjustment
c) Clean it
d) Collect refrigerant
e) Repair
f) Make vacuum and load
a) Verify the air or water circuits (fl ow, fi lter
cleanliness etc.)
b) Verify defrost
c) Replace fi lter
d) Search for leaks, complete charge
e) Temperature of air or water in condenser very
low (air or water fl ow very high), adjust fl ow
f) Repair
a) Check diff erential, fuses
b) Verify the safety chain of the electronic
control
c) Verify electronic control
d) Replace
e) Replace
f) Wait for reactivation, verify intensity absorbed
a) Control line voltage and locate voltage drop
b) Verify connections
a) Verify charge
b) Increase diff erential
c) Search for leak, reload unit
d) Clean, verify evaporator air circuit
e) Replace or repair
f) Replace, as well as fi lter
g) Replace
a) Fix
b) Add oil to recommended level
c) Replace
a) Place base over shock absorbers
a) Locate and repair
b) Replace
c) Verify parameters
d) Tap with running compressor Replace if
necessary
e) Locate and repair
23
Advertisement
Table of Contents
