11
Overcurrent unit of SPCJ 4D29
Low-set overcurrent stage I> *
Start current **
- at definite time characteristic
0.5...5.0 x I
n
- at inverse time characteristic ***
0.5…2.5 x I
n
Time/current characteristic
- definite time characteristic
- operate time t>
0.05...300 s
- inverse definite minimum time (IDMT)
characteristic as per IEC 60255-3 and BS 142
Extremely inverse
Very inverse
Normal inverse
Long-time inverse
- special type inverse characteristic
RI-type inverse
RXIDG-type inverse
- time multiplier k
0.05...1.0
High-set overcurrent stage I>> *
Start current
0.5...40 x I
n
and
∞
, infinite
Operate time t>>
0.04...300 s
Earth-fault unit of SPCJ 4D29
Low-set earth-fault stage I
0
> *
Start current
0.1...0.8 x I
n
Time/current characteristic
- definite time characteristic
- operate time t
0
>
0.05...300 s
- inverse definite minimum time (IDMT)
characteristic as per IEC 60255-3 and BS 142
Extremely inverse
Very inverse
Normal inverse
Long-time inverse
- special type inverse characteristic
RI-type inverse
RXIDG-type inverse
- time multiplier k
0
0.05...1.0
High-set earth-fault stage I
0
>> *
Start current
0.1...10.0 x I
n
and
∞
, infinite
Operate time t
0
>>
0.05... 300 s
* Note!
The operation of the low-set stage based on
inverse time characteristic will be blocked by
starting of the high-set stage. Then the operate
time of the overcurrent unit is determined by
the set operate time of the high-set stage at heavy
fault currents. In order to obtain a trip signal,
the high-set stage must be routed to a trip output
relay.
** Note!
If the set start current exceeds 2.5 x I
n
, the
maximum continuous carry of the energizing
inputs (4 x I
n
) must be noted.
*** CAUTION!
Never use start current settings above 2.5 x I
n
at
inverse time operation although allowed by the
relay.
