Manual 37137B
ESDR 4 - Current Differential Protection Relay
Chapter 1.
General Information
The ESDR 4 is a three-phase current differential protection relay for generators and motors (protected object).
The currents flowing in the individual lines are each measured using a current transformer on both sides of the
protected object. They form the protection area boundary or zone. All two or three-phase short circuits and line-
to-earth faults within this protection area are detected by the ESDR 4 as fault currents which initiate tripping.The
unit does not trip if fault currents occur outside the protection zone. In this way, a selective protection is guaran-
teed.
The ESDR 4 consists of a basic unit plus various options. The model designation is determined as follows:
ESDR 4 0 5
-h0018
B
Mounting
[B]..Front panel mounting
[M]..Rear wall mounting
Hardware variation
Special types; e.g. other relays
Current transformer, secondary
[1] = ../1 A
[5] = ../5 A
Potential transformer, secondary
[0] = not available
[1] = 100 Vac
[4] = 400 Vac
Type
Examples:
ESDR 401B (Standard unit, ../1 A CT input, for front panel mounting)
ESDR 405B (Standard unit, ../5 A CT input, for front panel mounting)
Intended Use
The unit must only be operated for the uses described in this manual. The prerequisite for a proper
and safe operation of the product is correct transportation, storage, and installation as well as careful operation
and maintenance.
NOTE
This manual has been developed for a unit fitted with all available options. Inputs/outputs, functions,
configuration screens and other details described, which do not exist on your unit may be ignored.
The present manual has been prepared to enable the installation and commissioning of the unit. Due to
the large variety of parameter settings, it is not possible to cover every possible combination. There-
fore, this manual is only a guide. In case of incorrect entries or a total loss of functions, the default set-
tings can be taken from the enclosed list of parameters.
Page 6/35
© Woodward
