User manual
Static Transfer Switch
UNB
User Manual
Page 24 (28)
ELTEK VALERE DEUTSCHLAND ©2009 UM_UNB_E_R04
5. Maintenance
In general, the static transfer switch UNB is maintenance-free.
A yearly inspection with following checks is simply recommended:
Correct fan operation
Mechanical inspection
Removal of dust and dirt, especially on radiating surfaces
Check for internal dust or humidity
Attention! Dust combined with dew or water may influence or destroy the internal electronic circuits.
Dust inside the unit can be blown out with dry compressed air.
The intervals between those checks depend on ambient conditions of the installed module.
6. Trouble shooting
If a failure occurs in the system, the LED “Alarm” is illuminated according to the adjustments in the customer menu,
item “Configuration of Collective Failures” (see diagram “customer menu”).
The failures are shown in clear text modus in the display “Alarm messages”.
The display “Alarm messages” can be entered from the basic display by pressing ESC (please also see section
4.3.3).
Basic display
Alarm messages Possible reason Corrective action
Source 1 fail. Mains voltage or frequency not ok Check mains voltage/inverter output voltage
Source 2 fail. Inverter voltage or frequency not ok Check inverter output voltage/mains voltage
Synchr. Error Inverter voltage is not synchronous
to mains
No mains voltage available or
frequency of mains voltage is not stable (out of
frequency tolerance range)
Inverter fail. Inverter failure CAN communication with one ore more Inverters
failed
Inverter failure detected via CAN
UNB overtemp UNB over temperature Check the air flow
Check admissible ambient temperature
UNB overload UNB output current to high Reduce load current
INV overload Actual output current exceeds the
combined INV power
Reduce load current or
increase INV power by additional inverter
DC-voltage low Battery voltage low Check DC voltage system
DC-voltage high Battery voltage high Check DC voltage system
Ubatt< warning Battery voltage < warning level Check DC voltage system
Ubatt> warning Battery voltage > warning level Check DC voltage system