ABB SPAJ 111 C User Manual page 15

The sensitive earth-fault relay can be used for
the unbalance protection of a capacitor battery,
provided that the capacitor battery is composed
of two star-connected batteries. A capacitor
battery is made up of a great number of fuse-
protected capacitors connected in serias and
parallel. When a fuse blows a small unbalance
appears between the capacitor batteries and it
can be measured with the sensitive earth-fault
relay SPAJ 111 C. Two-stage protection is used,
Switch SG1/SPCJ 1C7
1 1 t> = 0.5...10 s
}
2 1
I > = 0.2...2% x I
0
3 0
4 0 no latching
5 0 not in use
6 1 }
I >> = 1...8% x I
0
7 0
8 0 t>> = 0.05...1s
Σ
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When the switches are set as above, the output
contacts of relay SPAJ 111 C provide the follow-
ing signals:
Contact Function
65-66 Signal on tripping, stage I
68-69 Circuit breaker trip signal, stage I
80-81 Signal on tripping, stage I
77-78 Start signal, stage I
73-74-75 Start signal, stage I
70-71-72 Self-supervision signal
the first stage is signalling and the second stage
trips the circuit breaker.
The settings of the relay are to be determined by
the manufacturer of the capacitor battery, be-
cause the settings depend on the number of
capacitor units and their ratings.
The selector switches of the earth-fault relay
SPAJ 111 C can be set as follows:
SGB/SPCJ 1C7
0 not in use
0 not in use
n
0 not in use
0 stage t> not blocked
0 stage t>> not blocked
0 not in use
n
0 not in use
0 not in use
>
0
>>
0
>>
0
>>
0
>
0
SGR
0 no incoming blocking signal
1 I >> start signal to relay D
0
0 no I > start signal to relay D
0
0 no I >> trip signal to relay D
0
1 I >> trip signal to relay C
0
0 no I >> trip signal to relay A
0
0 no I > trip signal to relay C
0
0 no I > trip signal to relay B
0
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