Installing Plug-In Unit - ABB Relion 620 Series Installation Manuals

Section 4
Mounting
4.2.2
12
GUID-A04EACAD-96E1-435A-9E53-D25549F89459 V1 EN
Figure 2: Detaching a plug-in unit from the case
The protection relay features an automatic short-circuit mechanism in
the CT connector. Therefore, detaching the plug-in unit will not open
the secondary circuit of the CT which could cause dangerously high
voltages.
Do not touch terminals inside the case after removing the plug-in unit.
Live terminals can be inside the case.
The signal connectors are left open when the plug-in unit is detached.

Installing plug-in unit

The protection relay is constructed in a way that a plug-in unit with voltage- or current-
measuring inputs can only be plugged into a corresponding case. This prevents fitting
an unsuitable plug-in unit into a wrong case.
1MRS757641 E
620 series
Installation Manual