# DEIF TDU Transformer Differential Protection Unit

> transformer-protection - Transformer differential and backup overcurrent protection for hybrid renewable, industrial and marine power applications

**Voltformer canonical:** https://voltformer.com/product/deif-tdu-transformer-differential-protection-unit - markdown version: https://voltformer.com/product/deif-tdu-transformer-differential-protection-unit.md

## Overview

- **Brand:** DEIF
- **Product family:** TDU Series
- **Application:** Transformer differential and backup overcurrent protection for hybrid renewable, industrial and marine power applications
- **Product type:** transformer-protection

## Protection & Control Functions

- **ANSI Functions:** 87T, REF/87N, 49, 50/51, 50N/51N, 50BF
- **Transformer Windings:** 2
- **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):** Configuration-dependent
- **Redundancy (PRP/HSR):** No / Optional
- **Protocols:** IEC 61850, Modbus TCP, CANbus
- **Engineering Software:** DEIF USW

## Electrical Interface

- **Frequency:** 50/60 Hz
- **Nominal Current:** 1 A / 5 A
- **Auxiliary Supply:** 18-36 Vdc / 100-240 Vac
- **Operating Temperature:** -25 to +70 °C

## Standards

- IEC 60255
- DNV GL Marine
- CE

## Sources

- https://www.deif.com

- **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.