Troubleshooting - SCM CUBO2 SMART Oem Manual

OEM Manual – CUBO

Troubleshooting

12
Symptom/alarm
Probes alarm/ wrong
reading
Missing communication
between Hecu and PSD
(power+/Inverter)/
ALW24
MT compressor does
not start
Missing communication
between Hecu and
evaporators
(MPXPRO/ULTRACELLA)/
ALW37
Low SH alarm or DSH
alarm (ALW10/ ALT15/
ALT15)
SMART
2
Possible Cause
- wrong connection
- wrong configuration
- wrong range (for pressure probe)
- wrong type of probe
- wrong placement of probe
- broken probe
-Power plus device offline.
-No communication
HECU controller and PSD (Inverter
for compressor BLDC)
- Some blocking alarm is forcing off
the compressor
- Regulation status of the unit is
OFF
- Most of evaporators
performing a defrost (only if
evaporator controllers
connected to the CDU via RS485)
- Wrong configuration of PSD
(power+ driver)
- Wrong connection of serial line
- Wrong serial address setting
- Liquid is coming back to the
compressor
- Wrong reading of SH probes
(temp. and pressure)
- Wrong reading of discharge temp
probe
Check
Check the
configuration of the probe:
- type of probe
- wirings
- probes range (min and max)
- compare the value read by the probe
with the value read by a manometer
- check the PSD power supply (it must
between be powered)
- check the RS485 wiring between
HECU and PSD
- check the serial address set in the PSD
(dip switch configuration)
- check the PSD address set in the
HECU controller
- Check the active alarm and try to reset
the alarm (consulting the alarms table
suggestions)
- Switch ON the unit
are - Check the Defrost setting on mask
FBB15 (only if evaporator controllers
are are connected to the CDU via RS485)
- Force the download settings from
Hecu Controller to PSD
- Check the RS485 wirings/connection
- Check the serial address set in the
evaporator controller
- Check the protocol and baudrate
(Modbus, 19200bps)
- Check the SH in the evaporator
- Check the
Expansion valve in the evaporator
- Check the position of the probe and
be sure they are reading properly
- (for MT Comp or Parallel comp) check
that liquid is not coming back from
RPRV valve. This can happen in case of
an overcharge of refrigerant
connection and the
right operation of
Pag. 32