Woodward 5448-897 Current Differential Protection Relay

The ESDR 4/4T offers a three-phase current differential

protection for generators, motors, and transformers that are

interconnected. Two different versions offer a maximum of

flexibility and protection for your equipment. These are:

• ESDR 4 - Current differential protection for generators

and motors.

• ESDR 4T - Current differential protection for generators,

motors, and transformers in unit connection.

The current flowing in the individual conductors is meas

ured by means of current transformers installed on both

sides of the protection zone. These transformers form the

limits of the protection zone. Any two-phase or three-phase

short circuits and ground faults are recognized by the

ESDR 4/4T as fault currents. By means of freely configur

able relays, the unit will indicate if any of the adjusted fault

current limits have been exceeded. In the event that fault

currents occur outside of the protection zone, the unit does

not cause an opening operation. Hence the unit can be

used in protection systems requiring selective tripping op

erations.

To adapt the network configuration to the ESDR 4T it is

possible to change the phase shift of the transformer via

selecting the vector group in the display. The different

nominal currents of the high and low voltage side of the

transformer as well as the transformer ratio may be config

ured. Every measuring point may be set separately. These

features permit the ESDR 4T to be universal in its applica

tions.

The ESDR 4/4T permits design simplification of the switch

gear cabinet, facilitates the commissioning, ensures the

operation of the system, is user friendly, and increases the

availability of the system.

Principle: fault a) outside [=no alarm] b) inside [=alarm] of the

protected area

ESDR 4/4T

Current Differential

Protection Relay

DESCRIPTION (continued)

Features

• True RMS 6× current measurement, 3phase

system on both sides of the protected zone

• Secondary current transformer output avail

able as ../1 A or ../5 A

• Configurable trip set points for

o differential current (Id)

o stabilizing current (Is)

• Configurable delays

• 4 alarm relays

• 3 discrete inputs (for blocking, acknowledg

ment, and configuration)

• Two-line LC display

ESDR 4 (unique features)

Current differential protection relay for motors

and generators.

• Configurable tripping characteristic

• Configurable independent tripping values for

o differential current protection (Id)

o stabilizing current protection (Is)

ESDR 4T (unique features)

Current differential protection relay for motors,

generators, and transformers that are intercon

nected.

• Configurable tripping characteristic

• Configurable independent tripping values for

o differential current protection (Id)

o stabilizing current protection (Is)

• Configurable transformer ratio

• Configurable vector group

• Transformer inrush detection/suppression

• Individual configuration of the nominal current

for the high and low voltage side of the trans

former

• Configurable transformer ratio separated for

currents of high and low voltage side of the

transformer

Accuracy..........................................................................................Class 1

Power supply.....................................................................24 Vdc (+/-25 %)

Intrinsic consumption....................................................................max. 6 W

Ambient temperature Storage....-40 to 85 °C (-40 to 185 °F)

Operation......-20 to 70 °C (-4 to 158 °F)

Ambient humidity......................................................95 %, non-condensing

Current...........................................................................................isolated

Rated current (Irated).....................................................[1] ../1 A or [5] ../5 A

Current carrying capacity...............................................................5.0×Irated

Load.............................................................................................< 0.15 VA

Rated short-time current (1 s)...................[../1] 100.0×Irated, [../5] 30.0×Irated

Discrete inputs..............................................................................isolated

Input range........................................................................18 to 250 Vac/dc

Input resistance.....................................................................approx. 68 kΩ

Relay outputs........................................................................potential free

Contact material...............................................................................AgCdO

Load (GP).................................................24 Vdc@2 Adc, 250 Vac@2 Aac

Pilot duty (PD)......................................................................24 Vdc@1 Adc

Housing......................................................Type APRANORM DIN 43 700

Dimensions.......................................................................144×72×199 mm

Front cutout..........................................................138[+1.0] × 68[+0.7] mm

Connection................................................screw/plug terminals depending

on connector 2.5 mm² (14AWG) or 4 mm² (12AWG)

Front.................................................................................insulating surface

Protection system.....................................IP42 from front (IP21 from back)

Weight.................................................................................approx. 1.000 g

Disturbance test (CE).........tested according to applicable EN guidelines

Listings...............................................UL/cUL listed for ordinary locations

Approvals....................................GL (Germanischer Lloyd) only ESDR4T