General Description; Installation Instructions; Principle Of Operation - ABB RD2 Handbuch

General description

The RD2 differential relay, combined with an external toroidal
transformer, protects line cables against earth directed faults. The
RD2 version cod.EG 316 2 can be powered on AC (from 230V to
400V). The RD2-48 version cod. EG 413 7 can be powered on AC /
DC (from 48V to 150V) via the same pair of terminals. Minidip
switches are provided to select sensitivity and tripping time.
An exchange contact (NO-NC) is provided for output.

Installation instructions

1°
2°
DIN EN 50022 (35 mm )

Principle of operation

If an earth leak current occurs (differential current), the toroidal
transformer supplies a signal to the RD2 differential relay, which
processes it and compares it with the set sensitivity value. When
this threshold level is exceeded, the set delay is enabled and then
the alarm contact is tripped.
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