Bender NGRM700 - CT Connection

Connection
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NGRM7xx_D00292_07_M_XXEN/02.2022
5.4 CT connection
Depending on the system to be monitored, a suitable measuring current transformer
has to be chosen. All common measuring current transformers (50 mA or 5 A on the sec-
ondary side) can be used. The following table helps you with the choice:
Tab. 5.1: Selecting the right measuring current transformer
System type AC + DC AC AC
I
NGR
1…25 A 5…25 A 5…1000 A
f
0…3800 Hz 42…3800 Hz 50/60 Hz
Transformation ratio
Bender measuring
current transformer
Measuring range (see
CTUB103 manual)
5 A 100:1
10 A 200:1
25 A 500:1
600:1
Length
connecting cables
max. 30 m max. 40 m max. 25 m
(4 mm²/AWG12)
max. 40 m
(6 mm²/AWG 10))
provided cable or
0.75…1.5 mm²/AWG18…16
I
Δn
Type
CTUB103 W20…120
WS…
CTB31…41
CT: terminal k
NGRM7…: 50 mA NGRM7…: 50 mA NGRM7…: 5 A
CT: terminal l
NGRM7…: C NGRM7…: C NGRM7…: C
24 V
S1(k)
S2(l)
CTUB103
W…
WS…
k
l
k
l
k
l
CTB