Trip Of Non-Essential Load (Nel) - Deif GPC-3 Designers Reference Handbook

GPC-3 DRH 4189340587 UK
The diagram above shows that when the reverse power increases from P1 to P2, the delay will also be short-
er.
Settings related to reverse power protection:
1000 G -P> 1 AND 1010 G -P> 2
Set point:
Delay:
Output A:
Output B:
Enable:
Fail class:
1020 G -P> characteristic
Char. 1: Tripping characteristic for "1000 G -P> 1"
Char. 2: Tripping characteristic for "1010 G -P> 2"

5.4 Trip of Non-Essential Load (NEL)

The trip of Non-Essential Load (NEL) groups is carried out in order to protect the busbar against an imminent
blackout situation due to either a high load/current or overload on a generator set or a low busbar frequency.
The unit is able to trip three NEL groups due to:
● the measured load of the generator set (high load and overload)
● the measured current of the generator set
and
● the measured frequency at the busbar.
The load groups are tripped as individual load groups. This means that the trip of load group no. 1 has no
direct influence on the trip of load group no. 2. Only the measurement of either the busbar frequency or the
load/current on the generator set is able to trip the load groups.
DEIF A/S
Reverse power protection limit
Time delay
Select alarm output A
Select alarm output B
Enable/disable the protection
Action when protection is activated
Protections
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