RDR-1D IDMT EARTH FAULT RELAY DRAW OUT WITH SELF CT SHORTING——Draw-out Relay

Created on 2025.10.30

PROTECTION RELAYS

RDR-1D
IDMT EARTH FAULT RELAY
DRAW OUT WITH SELF CT SHORTING
RDR series relay have been designed for controlling, protecting and monitoring industrial, utility distribution networks and substations. They can also be used as part of a protection scheme for feeders, transformers and generators.

Micro controller based numeric design
Measures true RMS
Rated input current selectable 1A or 5A,
50/60 Hz
Circuit breaker failure detection
Trip circuit supervision
Harmonic block feature programmable

DI/DO programmable
Event recorder (100 records)
128x160pix (1.8") color LCD display+8 Leds for signalization
RS-485 & USB communication
CT terminal with Self-shorting block
Normal insertion LED indication

Protection features F50N/51N: Earth Fault elements F50H: Harmonic blocking F50BF: Circuit Breaker Failure Protection F74TC: Trip circuit supervision F86: Lockout	Control 3 Output Relays (Programmable) 1 Output Relays (Trip Circuit supervision) 1 Output Relays (Self-check) 4 Digital input (Trip Circuit supervision, reset, trip)
Time current curves Normal Inverse 1.3(IEC A) Normal Inverse 3.0(IEC A) Very Inverse 1.0(IEC B) Extremely Inverse 0.64(IEC C) Extremely Inverse 1.0(IEC C) Moderately Inverse 1.3(IEEE MI) Moderately Inverse 3.0(IEEE MI) Long Inverse (LI) Def. Time(DTL)	Measurements Real time measurements: IA - IB - IC - I0 Trip recording: last 100 trips with date & time Power supply ratings Type 1: 18-60VDC, 500mA Type 2: 85-265VAC / 88-300VDC
Software RDRCom1 Program interface for device management	Mounting 1 Module box totally draw-out execution IP44 protection case (on request IP54)

Earth fault protection (50N/51N)
The independent two stages are available for earth fault protection. For first stage (Ie>) the user can select definite time delay or inverse time delay with different type of curves. The second Hi-Set stage can be configured with definite time only.

Harmonic blocking (50H)
Harmonic block detects high inrush current inflows that occurs upon connection of transformers or rotating machines. The function will block the phase over-current and earth fault elements.

Circuit breaker failure protection (50 BF)
The CB Failure Protection is based on supervision of phase and earth currents after tripping events. The test criterion is whether all phase currents have dropped to less than 5% of In within tCBFP. If one or more of the phase currents have not dropped to specified current within this time, CB failure is detected and the assigned output relay is activated.

Trip circuit supervision (74TC)
This feature continuously supervises trip circuit of both pre closing and post closing conditions in circuit breaker. It detects tripping mechanism failure like circuit breakage contact degeneration in wires, contacts and coils. Note: Trip counter is incremented on the basis of getting trip command from relay and not on the basis of external mechanism (circuit breaker) operation.

Programmable Input Quantities
n: Rated primary current of phase Cts	1-10000A step 1A
Secondary current of phase Cts	1/5A
Fr: System frequency	50/60Hz
50N/51N(I0>): First earth fault element
Function enabling	ON/OFF
Current pick-up range	80-100%xIp (0.8-1xIp) step 1%
Current setting range	20-300%xIp (0.2-3xIp) step 1%
Definite trip time delay(10x[Ie>]) in inverse time operation modes	0.02-1.5x trip time delay (10x[Ie>]) step 0.01 0.02-260Sec (curves: DTL)
Output delay (TR)	30ms
Time current curves	IEC A / IEC B / IEC C / IEEE MI / LI / DTL
50N/51N(I0>>): Second earth fault element
Function enabling	ON/OFF
Current setting range	50-1000%xIp (0.5-10xIp) step 1
Trip time	0.02-60s step 0.01
Output delay (TR)	30ms

Typical characteristics

Typical characteristics
Accuracy at reference value of influencing factors	±0.5-1% for measurements
Rated current	1A/5A
Current overload	400A for 1 sec; 2.5xIn continuous
Burden on current input	0.2VA a In = 1A; 0.4VA a In = 5A
Average power supply consumption	≤10VA
Output relays	6 A; Vn = 250 V
	A.C. resistive switching = 1500W (400V max)
	make = 30 A (peak) 0.5 sec.;
	break = 0.3 A, 110 Vcc,
	L/R = 40 ms (100,000 op.)