NHP TemBreak PRO P, Руководство пользователя

Страница: 36 / 66

Protection Settings
36
TemBreak PRO
P_BE-UM-001-EN V1.3.0
Ground/Earth Fault Protection (GF)
Ground Fault (GF) protection is protection against high strength insulation / earth faults. An LSIG P_BE OCR is required for both 3P and 4P MCCBs to
permit GF protection. P_BE OCRs with LIS only do not have GF protection.
GF pickup current I
g
is fixed at I
g
= 0.4 x I
n
and is not adjustable.
The l
g
trip threshold tolerance for ground protection is ±10%.
GF time delay t
g
is also fixed at t
g
= 200ms and is not adjustable.
The trip time tolerance for ground protection is -20 ms / +50 ms
GF protection can be turned ON or OFF using the GF dial on 3P MCCBs by setting the dial to the ON or OFF position respectively.
For 4P MCCBs, the N (%) dial is also used for turning GF protection ON or OFF by setting the dial to any position on the right for ON, or any position on the
left for OFF. See
Neutral Protection (NP) section for more information on the N (%) dial.
Ground Fault Protection Settings Description
G
I
g
= 0.4 x I
n
Ground fault protection threshold
t
g
= 200 ms Ground fault delay
Notice : Enabling GF for 3 pole MCCBs on a 4-wire system may result in nuisance tripping in the case of
imbalanced loads. It is recommended in this case that GF should be disabled.