User’s Manual 31
Normally, with the board in the MANUAL mode the users are switched on the mains. Only if
the engine is running, if the generator is “present” and the delay before the supply has passed
- P06 (or if the temperature exceeds the minimum threshold set with P55), the operator has
the opportunity to switch them on the generator. To do that, press at the same time “MODE /
ACK” and “F1” for one second (such combination is highlighted on the front panel of the board
with the indication “MANUAL CHANGE-OVER”. This command works as “toggle”, that is, if
the operator gives again the order the users are again switched on the mains.
When the users are switched on the generator set, they are automatically switched on the
mains if the generator gets “absent” or in presence of deactivations and/or blocks.
The control sequence of the generator set in the AUTOMATIC mode develops as follows:
1. Start requests wait (typically mains failure)
2. Generator set starting attempts
3. Generator presence wait
4. Delay before supply the power
5. Switching users on the generator
6. No start requests wait
7.
Users’ switching on the mains
8. Engine cooling cycle
9. Engine shutdown cycle.
In this phase the engine is dead. The board waits until the mains get “absent” or for at least
one of the other start requests (see par.5.1.1).
The board tries to start automatically the engine. The number of starting attempts to execute
can be programmed through the parameter P10. If, after those attempts, the engine doesn’t
start, the start failure block is activated (“OVERCRANK”). Furthermore, the duration of the
starting impulse can be set (parameter P08) as well as the delay between two attempts
(parameter P38).
For each attempt the following operation are executed:
1.
The “FUEL SOLENOID” output (terminal 22) is enabled. Such output is automatically
removed during shutdown cycles or when the engine is dead for 20 seconds.
2. Th
e “STOP SOLENOID” output (terminal 18), used for the excitation shutdown, is disabled
(it should already be disabled unless the starting request occurs during a stop cycle). If
the engine is already running, the procedure stops here.
3. If the preheat functio
n for diesel engines is enabled the “AUX OUTPUT 1” (terminal 15) is
enabled for the time set with the parameter P20 (if such time is equal to 0 the preheat
function is disabled). In this phase the display “MULTIFUNCTION” shows the message
“PRE”. At the end of this phase the output is disabled passing to phase 2.
