Scribd
Upload
115 views1 page

Guide Ground Fault Protection

This document provides information about external current transformers (CTs) used for residual ground fault protection and source ground return protection with Masterpact circuit breakers. It specifies that the CTs must be installed and wired consistently with the phase CTs. Cable requirements are also listed, such as maximum length and cross-sectional area. The document concludes by providing the catalog numbers for a CT and module used for source ground return protection.

Uploaded by

Kgolagano Mmusi
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
115 views1 page

Guide Ground Fault Protection

This document provides information about external current transformers (CTs) used for residual ground fault protection and source ground return protection with Masterpact circuit breakers. It specifies that the CTs must be installed and wired consistently with the phase CTs. Cable requirements are also listed, such as maximum length and cross-sectional area. The document concludes by providing the catalog numbers for a CT and module used for source ground return protection.

Uploaded by

Kgolagano Mmusi
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 1

External transformer (CT) for For Masterpact NT and NW08/40

residual GF Protection Wathever the Masterpact

DB117330
feeding type, by open or
It is used with 3P circuit breakers and is installed on the bottom side, the power
neutral conductor to achieve a GFP protection of connection and the
residual type. terminal connection of
external CT are
compulsary the same of
DB117297

those phases CT ones.

DB117308
Cabling precautions:
b shielded cable with 2 twisted pairs
b shielding connected to GND on one end only
b maximum length 5 meters
b cable cross-sectional area to 0.4 to 1.5 mm2.
b recommended cable: Belden 9552 or equivalent Masterpact NW40b/63
b the external CT rating may be compatible with the
DB117307

circuit breaker normal rating:


NT06 to NT16: CT 400/1600
NW08 to NW20: CT 400/2000

DB117309
NW25 to NW40: CT 1000/4000
NW40b to NW63: CT 2000/6300.

The signal connection Vn is necessary only for power


measurement (Micrologic P/H). Feeding by open side H2 is connected to source
side and H1 to receiver side..
If the 2000/6300 current transformer is used: Alimentation Feeding by bottom side H1 is
signals SG1 and SG2 must be wired in series, signals connected to source side and H2 to receiver side.
X1 and X2 must be wired in parallel.
Catalog Numbers
ratings (A) NT NW

400/2000 33576 34035

1000/4000 34035

2000/6300 48182

External transformer for source b Cable cross-sectional area to 0.4 to 1.5 mm2
H1 is connected to
b Recommended cable: Belden 9552 or equivalent
ground return GFP protection source side and
b Terminals 5 and 6 are exclusives:
H2 to receiver side.
It is installed on the from LV transformer starpoint to the the terminal 5 for Masterpact NW08 to 40
ground link and is connected to Micrologic 6.0 trip unit the terminal 6 for Masterpect NW40b to 63.
by “MDGF summer” module to achieve the ground
DB117310

fault protection of SGR type.


DB117311

Cabling protections:
b unshielded cable with 1 twisted pair
b shielding connected to GND on one end only
b maximum length 150 meters Catalog Numbers
Current Transformer SGR 33579
MDGF module 48891

39

You might also like