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Schneider Electric REL21704 — General Purpose Relays

Schneider REL21704 MiCOM P127 protection relay (discontinued)

MPNREL21704
Obsolete

Schneider Electric MiCOM P127 REL21704 voltage/current protection relay, 1 A nominal, 12 discrete inputs, 9 discrete outputs, DNP3 IEC 60870-5-103 Modbus RTU, flush mount, 250 V DC supply.

$3,749.61Ref. price · indicative, final on quote
Schneider Electric REL21704 datasheet (PDF)
Source DocumentedChannel stated on listing & quote
Condition PhotosReal unit photos / video on request
WhatsApp AnswersFast human replies for machine-down parts
Worldwide DispatchDHL/FedEx — transit quoted per order
Independent China distributor & sourcing agent· Listing updated Sep 2026

Specifications

REL21704 — Mechanical
ParameterValue
Width103 mm
HeightTotal: 177 mm Embedded: 157.5 mm
DepthTotal : 270 mm Embedded : 240 mm
REL21704 — Other specifications
ParameterValue
Device mountingFlush
Protection typeANSI 50/51 : overcurrent ANSI 79 : recloser Cold load pick-up ANSI 50G/51G : earth fault ANSI 86 : lockout ANSI 47 : negative sequence overvoltage ANSI 27 : undervoltage ANSI 59 : overvoltage ANSI 81R : rate of change of frequency ANSI 59N : neutral voltage displacement ANSI 49RMS : thermal overload protection ANSI 81L : underfrequency ANSI 37 : phase undercurrent ANSI 46 : negative sequence overcurrent ANSI 67N : directional earth fault ANSI 67W : earth fault wattmetric ANSI 81O : overfrequency ANSI 62/50BF : breaker failure ANSI 64 : restricted earth fault ANSI 67P : directional phase overcurrent ANSI 51V : voltage-restrained overcurrent
I/O channels4 current input CT...X/5 A and X/1 A 3 voltage 12 discrete
Discrete input voltage24...250 V DC 19.2 V standard variant 48...250 V AC 19.2 V standard variant 48...250 V DC 105 V further option 48...250 V DC 77 V further option 48...250 V DC 154 V further option 48...240 V AC 105 V further option 48...240 V AC 77 V further option 48...240 V AC 154 V further option
Switchgear diagnosis typeTrip circuit supervision ANSI code: TCS CT supervision ANSI code: CTS VT supervision ANSI code: VTS
Supply voltage24...250 V DC 19.2...300 V 48...250 V DC 38.4...300 V 48...240 V AC 38.4...264 V
Communication port supportRS485 RS232
Communication port protocolDNP3 IEC 60870-5-103 Modbus RTU
Control and monitoring typeCircuit breaker/contactor control
Network and machine diagnosis typeFault recording Event recording Disturbance recording15 s

Product details

Overview

The REL21704 is a Schneider MiCOM P127 voltage/current protection relay rated 1 A nominal, with 4 current inputs accepting X/5 A and X/1 A CTs plus 3 voltage inputs, 12 discrete inputs, and 9 discrete outputs. It supports DNP3, IEC 60870-5-103, and Modbus RTU protocols, runs on a 250 V DC supply, and is flush-mounted with a 103.0 mm width and 270 mm total depth.

Comparison with REL21201

The REL21704 has 12 discrete inputs and 9 discrete outputs; the REL21201 has 3 discrete inputs and 7 discrete outputs. The REL21704 also adds voltage inputs (3 voltage) and a broader protection suite including ANSI 79 recloser, ANSI 27 undervoltage, ANSI 59 overvoltage, and directional elements not present on the REL21201.

MPN
REL21704