Residual Current Protection Function - ABB SACE Emax Series Installation, Service And Maintenance Instructions

1 6 . 6 Residual current protection function

16.6.1 General
EMAX circuit-breakers can be equipped with a toroid fitted at the rear of the CB (at a max distance of ten meters) so as to ensure protection against
residual current ground faults.
In particular, the electronic releases which can ensure this function are as follows:
- PR122/P LSIRc,
- PR122/P LSIG fitted with a PR120/V module
- PR123/P LSIG.
The residual current protection function is available only in the event of a dedicated rating plug which carries sensitivity ranges and non-trip times
characterizing this function.
,
(tar)
The following table shows the available settings:
Available Settings
400
630
800
1250
2000
3200
The following table shows protection thresholds and times that can be set:
Thresholds Non-trip times
3A 0.06s
5A 0.10s
7A 0.20s
10A 0.30s
20A 0.40s
30A 0.50s
0.80s
Two toroidal sizes are available: the small toroid can be installed on E1 and E2 three-pole sizes, the medium toroid can be installed on E1 and E2
four-pole sizes and on E3 three-pole sizes.
The PR122/P LSIRc unit provides all PR122/P LSI functions but with one addition: protection against residual current faults.
Using PR122/P LSIG with additional PR120/V module, the protection against residual current is added to a unit having the characteristics of a PR122/
P LSI and all additional ones described for the PR120/V module, see par. 15.1.
With a PR123/P LSIG unit, the Rc protection function replaces the external G function (Gext); however, G function is retained.
The Rc protection is activated only when a rating plug dedicated to Rc function is available, and after correctly performing
the unit installation procedure.
This protection cannot be disabled.
L2234
Model
L2778
,
Apparatus
Doc. No.
1SDH000460R0002
Scale
Emax
Page No.
133/158