To read mains voltages, push “Select Mis” key until “L” indication will appear on the left
upper corner; at this point mains voltages will be showed on display. Push “Select Mis”
again and “G” icon will appear; generator line voltages will replace mains measure. If
generator is not running, “OFF” icon will appear which means unavailable genset
measurements.
The commutation is immediate (500ms delay from opening a contactor and closure the
other) and a phase sequence check is performed each switching procedure.
In manual mode, operative generator alarms are not detected, are available only
indicators LA and LM. “M” letter on the right side means single-phase system.
Automatic mode
Automatic mode allows to manage engine and transfer switch completely by software
logic, it’s not possible to start the generator or force switching through operative board,
“AUTO” indication will appear on the low left corner.
However with “Select Mis” is still possible to change displayed measurements from
generator and mains. When controller commands switching on mains or generator,
automatically values visible on display change in accordance.
Each phase is checked separately, so a phase failure will start the automatic intervention
procedure.
Alarms
If mains measurements are selected, in case of alarm will be possible to see one of these
messages on the left side of the display :
- “LOW VOLT” line voltage below programmed threshold ( P3 parameter );
- “HIGH VOLT” line voltage over programmed threshold ( P4 parameter );
- “PH.SEQ.ERR” in case of wrong phase sequence;
Both alarms cause an automatic intervention procedure.
Generator starting procedure begins after a programmable delay (P7 parameter).
With running generator, after another programmable timer ( P8 parameter), the controller
checks voltage status measured on alternator and in case of anomaly, one of these
alarms will be showed on display:
- “ERROR 1” if generator’s phase voltage is out of limits. ( P5, P6 parameters ).
- “ERROR 2” if generator’s frequency is out of limits. ( P12 parameter ).
- “ERROR 3” if generator fails to start.
If generator is working correctly, “ERROR 1” or “ERROR 2” alarms are showed if voltage
or frequency values are out of limits for the duration of programmed time ( P15 parameter)
To reset an alarm on display must be used “Aut/Man” with locked keyboard ( “LOCK”
key). The device returns on mains position and restarts commutation procedure towards
generator. If generator alarm is active and mains voltage returns back, automatically the
commutation will be switched on mains side.
