ABB REG316 4 Series - Page 282

ABB Switzerland Ltd REG 316*4 1MRB520049-Uen / Rev. F
3-244
RR'
N
3N
0.7 k
Es Es
1
2
2
=´
´
æ
è
ç
ö
ø
÷
³W
MTR MTR'
110 V
Uis
N'
N'
110 V
Uis
12
11
=´ =´
The injection voltage Uis depends on the value of the parallel
resistor R'
Ps
and can be either 6.4 V, 12.8 V or 25.6 V.
The minimum value of the resistor R'
Ps
in relation to the corre-
sponding injection voltage Uis can be seen from the following
table. The maximum possible injection voltage should be chosen
in each case.
R'
Ps
[W] Uis [V]
> 0.45 6.4
> 1.8 12.8
> 7.2 25.6
Table REX011-2
Design example:
U12kV
Gen
=
N
N
12 kV
3
600 V
3
1
2
=
Assumed: I 5 A
Emax
£
Determination of the grounding resistors:
Condition 1:
()
R' R'
12 kV
35A
3
600 V
3
12 kV
3
3
35A12kV
1.4
Es
Ps
2
2
+³
´
´
´
æ
è
ç
ç
ç
ç
ö
ø
÷
÷
÷
÷
=
´
´´
=
600
0
V
W
Condition 2: R' 130
3
600 V
3
12 kV
3
0
Ps
2
³´
´
æ
è
ç
ç
ç
ç
ö
ø
÷
÷
÷
÷
=WW.98
Assumed: R' 1
Ps
= .0 W