Models 3.2 - 13.2, controller µchiller
Blue Box - Page 64
SYMPTOM
OPERATION
PROBABLE CAUSE
POSSIBLE CORRECTIVE ACTION
COOLING
HEATING
A)
No compressor
⊗ ⊗
No mains power Check presence of mains power
running.
(display off)
⊗ ⊗
Main power switch Off
(position "O")
Turn mains power selector to
position "I"
⊗ ⊗
No power to control circuits
Check condition of fuses FU50,
FU51, FU52.
Check operation of the
transformer
⊗ ⊗
Incorrect phase sequence
(relay KA5 with only green
LED lit)
Invert two of the phase wires of
the power feeding line; when the
unit is powered up again both
the green LED and the yellow
LED should light
⊗ ⊗
Relay KA5 with green and
yellow LEDs off
Check fuses FU56;
If fuses are OK replace phase
sequence relay
B)
No compressor
running.
⊗ ⊗
Unit in stand-by mode Start unit (see relative section of
the manual)
(display on,
no alarm messages)
⊗ ⊗
No consent from service
thermostat
System at set-point temperature,
no heating/cooling demand;
check settings and operation.
⊗ ⊗
No external consent Check operation of circulator
pumps, flow switches, bleed air
from the system; check that
contacts 1 and 2 are closed,
check other external consents.
⊗ ⊗
Compressor motor burnt
out or compressor seized
Replace compressor
⊗ ⊗
Anti-recycle timer running Wait for 5 minutes until the
timer generates a consent
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