Blue Box SIGMA 2002, Installation, Installation, Operating, Operating, And Maintenance Manual

Page: 70 / 124

Models 3.2 - 13.2, controller
µ
chiller
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