Page 60
Operation and Maintenance
Envistar Top 04-21
DSET.190501.01.EN
Continuous product development may give rise to specification changes without notice.
7.3 Reversible heat pump (code TTC)
Alarm troubleshooting
Inspection
Possible cause
Corrective action
Has the high pressure
switch tripped?
YES
⇒
No or too low air flow across the
condenser
Check the air flow across the
condenser.
Rest the pressure switch manually.
Defective high pressure switch
Check/replace
NO
⇓
Is the alarm
“118 Compr 1,
Low evaporation pres-
sure” or
“176 Compr 2, LowEvap-
Pressure” displayed?
YES
⇒
Insufficient refrigerant volume
Look for leakage, seal the leak and
top up with refrigerant
No or too low air flow across
evaporator
Check/adjust the flow
Defective expansion valve
Check/replace
NO
⇓
Is the LED flashing red on
the frequency inverter?
YES
⇒
Phase failure/voltage failure
Check the 3-phase supply, measure
the incoming voltage.
Reset the frequency inverter by
switching off the voltage for 1
minute or more. Check that the
compressor is running without
dissonance.
Overload/defective stepless
compressor
Reset the frequency inverter by
switching off the voltage for 1
minute or more. Check that the
compressor is running without
dissonance.
NO
⇓
Is the alarm
“189 Phase Rotation
order”displayed?
YES
⇒
Incorrect phase sequence for
supply voltage on compressor 2
Shut off voltage and switch two of
the incoming phases
NO
⇓
Is the alarm
“94 Drive
offline”displayed?
YES
⇒
ThermoCooler HP does not have
supply voltage 3×400V
Connect supply voltage