4.7.6 NEL # reactive overload
These non-essential load trips (NELs) are for reactive overload protection. Tripping the NELs
reduces the reactive power load at the busbar, and thus reduce the load percentage on all the
running gensets. This can prevent a possible blackout at the busbar due to overloading the
running gensets.
The alarm response is based on the reactive power (all phases), supplied by the source, as
measured by the controller.
By default, up to three NEL trips are available.
Set
point
Value
time
Delay
These parameters are only visible if the non-essential loads are configured on the single line diagram.
Configure the parameters under
Configure > Parameters > Non-essential load trip > Trip #
>
Reactive overload
, where # is 1, 2
or 3.
Table 4.25
Default reactive overload NEL trip parameters
Parameter Range
Trip 1 > Reactive
overload
Trip 2 > Reactive
overload
Trip 3 > Reactive
overload
Set point
10 to 200 % of nominal reactive
power
110 %
110 %
110 %
Time delay 0.1 s to 1 h
5.0 s
8.0 s
10.0 s
Enable
Not enabled, Enabled
Not enabled
Not enabled
Not enabled
Action*
Warning
Warning
Warning
*Note: The NEL function also trips NEL #. You cannot reconnect the NEL until the alarm is deactivated. The alarm action cannot be
changed.
Inhibits: The trips are inhibited if the breaker to the busbar is open.
4.8 Input alarms
4.8.1 Digital input (DI) alarms
You can configure custom alarms for any of the controller digital inputs (DI). When the digital input (DI) is triggered the alarm
becomes active in the system and the controller does the associated alarm action.
HIGH input trigger example
Select
High
for the alarm trigger level.
By default, a digital input (DI) is normally open, and the
alarm is activated if the digital input is closed for longer than
the
Time delay
.
t
1
LOW
HIGH
Digital
input
Time
t
2
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