A
LARM
M
ONITORING
112-MOBL-3
E
XPLANATION OF
A
LARMS
Engine does not come to a standstill
This alarm is announced when the engine is still running after the stop procedure. This signalises that the
stopping equipment of the engine (stopping solenoid, gas valve, etc.) is defective.
Engine fails to start
This alarm comes up (and the automatic operation is locked) when the engine is not running when the start
sequence is over.
Engine fault
This alarm is activated if the engine stops without having a stop command from the control unit. The control
system is locked at the same time.
Overspeed
The generator frequency or the signal of a pick-up is used for this monitoring. The alarm G
ENERATOR
U
NDERVOLTAGE
must be enabled as a shutdown alarm when the generator frequency is used. This also
protects the engine if the generator voltage fails.
Alarms 13 and 14
The input signals for these two alarms can be delayed for 0 to 250 seconds. That means that the alarm
contact must be activated for the programmed time before the alarm comes up. Furthermore these two alarms
are also enabled in the operation mode O
FF
, however without the audible signal. Fault signals, which have to
be always signalled, can be monitored by this (e.g. tank filling level, leakage).
Battery voltage monitor
A delay time is started if the voltage falls below the lower limit. The timer is reset when the voltage rises
within this delay over this lower limit (not the upper limit). An alarm is announced when the delay time is
up.
A relay (with a break function) can be programmed for the direct output of the battery voltage monitor. It is
energised if the voltage is good. A remote signal is possible by this even in the operation mode O
FF
.
Analogue input alarms
The analogue inputs can be fitted with modules for various sensors (PT100, PT1000, current loops, thermal
elements, VDO sensors, MotoMeter for engine temperature and oil pressure etc.). Each analogue input can
be monitored for two alarm levels.
Generator CB tripped
The generator circuit breaker can be monitored for automatic tripping (e.g. by an installed over-current
tripping device). Additionally the mode
WARNING
/
SHUTDOWN
must be programmed for this alarm. The
alarm is internally triggered in case no feed back signal G
ENERATOR
CB
IS ON
is detected after running out
of the generator closing pulse.
Generator CB does not cut off
The alarm occurs when the generator CB is not off two seconds later after the Off-command. The genset gets
an internal start command and by this keeps the engine running and the generator CB remains on.
The engine stops when in this case a shutdown alarm occurs. An additional generator-coupling breaker can
be switched off by a programmed relay to disconnect the generator.
Alarms of the voltage monitor
An alarm is announced if a monitored voltage or frequency of the generator is out of its range. The alarm
itself has no influence of the actual voltage or frequency monitoring. That means, if the monitor has stated a
failure and triggered the alarm and later on the monitored function is again within its limit, the alarm is still
present until it is cancelled. For the internal controlling however, the actual state is used which means, that
the monitored function is effective as
NORMAL
.
Monitoring of the currents
The generator currents can be monitored for
−
Over-current (e.g. 110%).
−
Short circuit (e.g. 300%).
−
Unbalanced currents and
−
Thermal overload.
The response diagram for the thermal overload is shown further down.
Alarm Monitoring 112-MOBL-3 / 07-01-25
12 / 18
Changes without further notice reserved.