Relay Code

Relay codes for electrical protections according to the ANSI standard.

This app shows the relay codes used in electrical protections according to the ANSI standard.

It allows you to add the most consulted relay codes to favorites and share.

Becoming so in a great tool to read electric plans and electrical protections according to the ANSI standard from your mobile device.

1.- Main Relay Code:

32 - Directional power relay

32L - Low advance power

32N - Wattmetric Zero-Sequence Directional

32P - Directional power

32R - Reverse power

33 - Position switch

34 - Master sequence device

35 - Short circuit device that operates with brushes or sliding ring

36 - Polarization voltage or polarization device

49 - Machine Thermal Relay or Transformer / Thermal Overload

49RTD - RTD polarized thermal overload

50 - Instantaneous overcurrent relay

50BF - Breaker failure

50DD - Current disturbance detector

50EF - End Fault Protection

50G - Instantaneous ground overcurrent

50IG - Instantaneous overcurrent of isolated ground

50LR - Acceleration time

50N - Neutral instantaneous overcurrent

50 NBF - Neutral instantaneous breaker failure

50P - Instantaneous phase overcurrent

50SG - Instant overcurrent of sensitive earth

50SP - Instantaneous split phase current

50_2 - Instantaneous overcurrent of negative sequence

50/27 - Accidental Energization

50/51 - Instantaneous overcurrent / time delay relay

50Ns / 51Ns - Sensitive ground fault protection

50/74 - Ct Trouble

50/87 - Instantaneous Differential

51 - AC time overcurrent relay

51 - Overload

51G - Ground time overcurrent

51LR - AC inverse time overcurrent protection relay (rotor locked)

51N - Neutral time overcurrent

52a - Position of the AC circuit breaker (contact open when the circuit breaker is open)

52b - Position of the AC circuit breaker (contact closed when the circuit breaker is open)

2.- Acronyms:

AFD - Electric arc detector

CLK - Clock or timing source

CLP - Cold load collection

DDR - Dynamic disturbance recorder

DFR - Digital fault recorder

HMI - Human-machine interface

HST - Historian

LGC - Scheme Logic

MET - Measurement of the substation

PDC - phasor data concentrator

PMU - phasor measurement unit

PQM - Energy quality monitor

RIO - Remote input / output device

RTD - Resistance temperature detector

LRSS - Local / remote selector switch

VTFF - Vt Fuse failure