Chint NRE8 Electronic Overload Relay

Name: Chint NRE8 Electronic Overload Relay
Brand: CHINT
SKU: 1769746268709462016

Brand Name:Chint
Theory:Thermal Relay
Place of Origin:China
application:PROTECTIVE
Model Number:NRE8
Contact Load:High Power
Protect Feature:Sealed

Type

Current Setting Range

The Chint NRE8 Electronic Overload Relay is an advanced electronic overload relay providing precise motor protection with digital accuracy. Unlike thermal relays, the NRE8 uses current transformers and microprocessor technology for superior protection in critical applications such as HVAC systems, pumping stations, conveyor systems, and process automation.

Electronic vs Thermal Overload - Key Advantages

FAQs

A: Choose NRE8 for: critical motors where downtime is expensive, applications requiring earth fault protection, wide current adjustment range needs, or environments with temperature extremes where thermal relays may drift.

Description

Chint NRE8 NRE8-25 NRE8-40 NRE8-100 NRE8-200 NRE8-630 25A 40A 100A 160A 200A 315A 400A 500A 630A CHNT Electronic Overload Relay

Chint NRE8 Electronic Overload Relay

General

1 Certificates: CE, UKrSEPRO, UL;

2 Electrical ratings: AC50/60Hz, 690V;

3 Standards: IEC/EN 60947-4-1, UL508

Features
  1 Three-phase electronic type, tripping class10A;
  2 Energy saving up to 80% compared with bimetallic type;
  3 Phase-failure protection;
  4 Current setting continuously adjustable;
  5 Two indicator lights available for indicating normal, overload time-delay, phase-failure and phase-failure time-delay status respectively;
  6 Manual test mechanism;
  7 Manual reset button;
  8 A pair of N/C and N/O contacts;
  9 Two mounting versions: independent or combined with a contactor.

Additional information

Current Setting Range	0.1-0.4A, 0.25-1A, 1-4A, 4-16A, 10-40A, 30-120A, 80-200A
Type	Electronic Overload Relay

Technical Datasheet & Downloads

📄 Technical Documentation & Product Specifications

Download official engineering datasheets, certified test standards (IEC / UL / CE), wiring diagrams, and dimensional drawings for Chint NRE8 Electronic Overload Relay.

📥

Official Technical Datasheet (PDF) Complete electrical ratings, tripping characteristics, dimensions, and compliance specifications.

📐

2D/3D CAD & Dimensional Drawings STEP, DXF, and PDF CAD drawing files for panel builders and switchgear designers.

Technical FAQ & Selection Guide

💡 Frequently Asked Technical Questions & Selection Guide

Pure engineering specifications, tripping curve parameters, and electrical selection guidance for panel builders and system designers.

AC-1 / AC-3 Duty

How to calculate contactor rating based on motor power and utilization categories (AC-1 vs AC-3 vs AC-4)?

AC-3 rating applies to standard squirrel-cage motor starting and stopping during normal run (starting current 5–7x In). For non-inductive or purely resistive heating loads, use the higher AC-1 rating. For severe inching, jogging, and plugging applications (AC-4 duty), derate the contactor or upsize by 1 to 2 frame sizes to prevent contact erosion.

Coil Voltage Selection

How to choose the correct control coil voltage, frequency, and electronic wide-voltage options?

Standard AC coils include 24V, 48V, 110V, 220V/230V, 380V at 50/60Hz. For DC control loops or PLC outputs, specify DC coils or electronic wide-range AC/DC coils (e.g. 100V–250V AC/DC) which feature built-in surge suppression, low holding power consumption, and immunity to voltage dips.

Overload Coordination

How to size and coordinate the matching thermal overload relay (TOR) for Type 2 protection?

Select a thermal overload relay whose current setting range straddles the motor full-load current (FLA). Set the dial precisely to 1.0x motor nameplate FLA. For IEC 60947-4-1 Type 2 coordination, pair the contactor and relay with backed-up upstream fuses or fast-acting MCB/MCCB to prevent welding under fault conditions.

Auxiliary & Interlocks

What auxiliary contact blocks and mechanical interlocks can be added for motor reversing?

Units feature built-in 1NO or 1NC auxiliary contacts, expandable with top-mounted 2-pole or 4-pole auxiliary contact blocks (F4 / AX) and pneumatic timer delay blocks. For forward/reverse motor starters or star-delta starter assemblies, add side-mounted mechanical interlock units (MI) with electrical interlocking.

Ambient & Altitude Derating

How do ambient temperature and installation altitude affect contactor performance?

Standard ratings are calibrated for -5°C to +40°C. For ambient temperatures exceeding 55°C or altitudes above 2000m (where reduced air density diminishes heat dissipation and dielectric insulation), derate operational current by 2% per 100m above 2000m and verify insulation voltage limits per IEC standards.