A new genset priority order should be carefully considered, since it may cause genset starts and stops. You can select
Delayed
priority shift
before changing the priority, to prevent genset starts and stops while changing the priority. Alternatively, if all the
GENSET controllers are in SEMI mode while you set the genset priority, then this prevents unwanted automatic genset starts and/or
stops.
Input
If needed, assign the input under
Configure > Input/output
. Select the hardware module, then select the input to configure.
Table 7.4
Optional input
Function
I/O
Type
Details
Power management > 1st priority
Digital input
Pulse This input functions exactly like the
1st priority
push-button.
Setting the genset priority using the 1st priority push-button
You can set the genset priority manually by using the 1st priority push-button on the display unit of the gensets in the reverse of the
priority order you want.
1st priority push-button example
The system consists of gensets A, B, C and D. You want genset A to have priority 1, genset B to have priority 2, genset C
to have priority 3 and genset D to have priority 4.
1. Press the push-button
1st priority
on the genset's display unit (then wait for the LED next to the push-button to
come on) in the following order: D, C, B, A.
2. The priority order is then A, B, C, D.
Alternatively, if a button is wired to a digital input, with the
Power management > 1st priority
function configured, then pressing this
button has the same effect as pressing the 1st priority push-button on the display unit.
Setting the genset priority using the display unit
The display unit includes an interface to let the operator easily rearrange the genset priorities in the system.
More information
See
Configure
,
Priority
,
View or configure priority
for more information about how to change the priority for multiple
controllers.
Delayed priority shift
If
Delayed priority shift
is selected, then after a change, the new priority order only comes into effect during the next load-dependent
start/stop. If this is not selected, changes to the priority order may immediately result in genset starts and stops, since the gensets
that are running must correspond to the new genset priority order.
Delayed priority shift example
The priority order is A, B, C, D. The gensets are all the same size. Genset A is running.
The operator changes Genset A's priority to 3. The priority order is now B, C, A, D. When the power management system
requires a genset start, Genset B starts. At the same time, Genset C also starts. When Genset B and C are connected,
and the load-dependent stop timer expires, then Genset A stops.
7.3.4 Dynamic genset priority
For
Dynamic
priority, the power management system assigns the genset priority according to the order in which the gensets connect
to the busbar. This genset priority selection method maximises system reliability by prioritising the gensets that start quickly and
penalising slow starts and genset failure.
DESIGNER'S HANDBOOK 4189340911K UK
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