Table 8.15 Successful engine start sequence with start prepare
Start
attempts
1
Crank
Start
prepare
t1
t2
(1)
(3)
(2)
t1 = Start prepare (Parameters > Engine > Start sequence > Start
prepare > Start prepare)
t2 = Extended start prepare (Parameters > Engine > Start sequence >
Start prepare > Extended start prepare)
1. Start attempts
2. Start prepare: Engine > Start prepare (digital output) (optional).
a. At the start of each start sequence, the controller activates the
Start prepare output for the time in the Start prepare parameter
(t1). All other engine start outputs (that is, Stop coil, Crank ) are
not activated during this time.
b. If there is an Extended start prepare time (t2), then the Start
prepare output remains activated for this time during cranking. If
cranking stops before the extended start prepare timer stops,
then the controller deactivates the Start prepare output.
3. Crank: Engine > Crank (digital output). After the Start prepare time,
the controller activates the Crank output.
8.3.4 Interruption of the start sequence
These actions interrupt the engine start sequence:
• The Emergency stop digital input is activated (for example, from the operator, or a PLC)
• When the controller is in SEMI mode, there is a Stop engine command. For example: The operator pushes the push-button Stop
on the display unit.
• The following alarm actions:
◦ PMS-controlled stop
◦ Trip generator breaker and stop engine
◦ Trip generator breaker and shutdown engine
INFO
The Block alarm action will not interrupt the genset start sequence after it has begun. However, the Block alarm action
prevents a new genset start sequence from starting.
When the start sequence is interrupted, the controller does the following:
• Deactivates the Crank output.
• Activates the Stop coil output (if present). Alternatively, deactivates the Run coil output (if present).
• Deactivates the Start prepare output (if present).
There is no cooldown period when the engine start sequence is interrupted.
INFO
If Running detection is ON, the controller regards the engine as started. When the engine has started, the actions listed
here do not interrupt the engine start sequence, but result in a engine stop instead. The engine stop normally includes the
cooldown period configured in the controller. However, for a shutdown, there is no cooldown period.
8.4 Engine stop
8.4.1 Engine stop function
For a normal genset stop, the controller ensures that the genset runs for a cooldown period before stopping. If a shutdown alarm
action shuts down the genset, there is no cooldown period.
DESIGNER'S HANDBOOK 4189340911K UK Page 295 of 521
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