User’s Manual 33
The boards waits until the mains gets “present” and all the other start requests get off (see
par.5.1.1). Further, the arising of new faults of the generator set is checked.
In sequential order there are:
Opening of the generator set contactor (closed contact at terminals 58-59)
Change-over wait (set through parameter P22)
Closing of mains contactor (closed contact at terminals 61-62)
Please, consider that the status of each contactor cannot be inverted from the prior command
before the time set through the parameter P41 is lapsed from the last command.
The engine is kept running after the users’ switching on the mains for a time programmable
through the parameter P07. The reason is that the engine cools more quickly by running
without supplying then shutting it down.
The shutdown cycle is the following:
“FUEL SOLENOID” output (terminal 22) disabled
“STOP SOLENOID” output (terminal 18) enabled
Wait set through parameter P09
“STOP SOLENOID” output (terminal 18) disabled. If the VOLVO engine EDC function is
enabled (bit 3 of P61), the solenoid is driven only for two seconds but the board waits in
any case until P09 is elapsed.
At the end of the cycle, if the engine is still running, the
shutdown failure block (“F21”) is
activated (anyway the STOP SOLENOID output will not be enabled).
Up to revision 08.00.38, the automatic shut down cycle could be aborted if a new start request
arises. In some situations, this caused a false F01 or F03 blocks. So, from revision 08.00.39
a new start request can be processed only when the engine is stopped or when the shutdown
cycle is terminated.
The sequence in the TEST mode is fundamentally the same of that in the AUTOMATIC mode,
with the following differences:
The engine is started in any case, independently from the start requests.
The users’ switching normally is executed only in case of mains failure. The operator can
force it with the same procedure used in the MANUAL mode.
The engine is never stopped automatically, except for blocks and/or deactivations.
Therefore, the TEST mode can be used to test accurately the generator set without
disconnecting the users from the mains, but at the same time assuring the users’ power supply
from the generator set in case of mains failure.
