# NR Electric PCS-978 Transformer Protection Relay

> transformer-protection - Differential, restricted earth fault, overexcitation and backup protection for EHV/UHV two-, three- and multi-winding power transformers

**Voltformer canonical:** https://voltformer.com/product/nr-electric-pcs-978-transformer-protection-relay - markdown version: https://voltformer.com/product/nr-electric-pcs-978-transformer-protection-relay.md

## Overview

- **Brand:** NR Electric
- **Product family:** PCS-900 Series
- **Application:** Differential, restricted earth fault, overexcitation and backup protection for EHV/UHV two-, three- and multi-winding power transformers
- **Product type:** transformer-protection

## Protection & Control Functions

- **ANSI Functions:** 87T, REF/87N, 49, 50/51, 50N/51N, 24, 50BF, 27/59, 81
- **Transformer Windings:** 2, 3, 4
- **Supports Transformer:** Yes
- **Supports Feeder:** No
- **Supports Breaker Control:** Yes
- **Arc Flash Protection:** No

## Digital Integration & Protocols

- **IEC 61850 Edition:** Ed2
- **GOOSE:** Yes
- **Sampled Values (SV):** Yes
- **Redundancy (PRP/HSR):** Yes (PRP/HSR)
- **Protocols:** IEC 61850 Ed.2, GOOSE, SV, IEC 60870-5-103, DNP3
- **Engineering Software:** PCS-Studio

## Electrical Interface

- **Frequency:** 50/60 Hz
- **Nominal Current:** 1 A / 5 A, module-dependent
- **Auxiliary Supply:** 110-250 Vdc / 85-265 Vac
- **Operating Temperature:** -25 to +55 °C

## Standards

- IEC 60255
- IEC 61850
- IEEE C37.90
- GB/T 14285

## Sources

- https://www.nrec.com/en/index.php/product/productInfo/42.html

- **Source scope:** manufacturer-family
- **Last reviewed:** 2026-09-13

Manufacturer portfolio/family source. Confirm the exact order code, guaranteed ratings and project-specific options against the current OEM datasheet before procurement or an SLD study.

Technical ratings are configuration-dependent where stated by the manufacturer. Request project-specific verification before procurement.