ABB REG316 4 Series Operating Instructions Manual page 282

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