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