Chint NR2 Thermal Overload Relay
Chint NR2 Thermal Overload Relay
Chint NR2 Thermal Overload Relay
Chint NR2 Thermal Overload Relay
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Chint NR2 Thermal Overload Relay
Chint NR2 Thermal Overload Relay
Chint NR2 Thermal Overload Relay
Chint NR2 Thermal Overload Relay
Chint ND9 Indicator Light
Chint ND9 Indicator Light
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CHINT NC7 Series 3-Pole 4-Pole AC Contactor 9A-85A
CHINT NC7 Series 3-Pole 4-Pole AC Contactor 9A-85A

Chint NR2 Thermal Overload Relay

Brand Name:Chint
Theory:Thermal Relay
Place of Origin:China
application:PROTECTIVE
Model Number:NR2
Contact Load:High Power
Protect Feature:Sealed
Model
Current Setting Range (A)
SKU: 1769741117554696192 Category:

Where to Use NR2 Thermal Overload Relay?

The Chint NR2 Thermal Overload Relay is a thermal overload relay designed to protect three-phase motors from overload and phase failure. It works in conjunction with contactors (such as Chint NC1/NC2/NXC series) to provide complete motor protection in motor control centers, industrial machinery, pump stations, and conveyor systems.

How Does a Thermal Overload Relay Work?

The NR2 uses bimetallic strip technology. When motor current exceeds the set value for a sustained period, the bimetallic strip heats up and bends, triggering the auxiliary contacts to open the contactor coil circuit - safely stopping the motor before damage occurs.

Key Features

  • Adjustable Current Setting - Dial adjustment from 0.1A - 630A to match motor FLC
  • Phase-Failure Protection - Detects and trips on phase loss (single-phasing) which can burn out motors
  • Temperature Compensation - Maintains accurate tripping across ambient temperatures from -25°C to +55°C
  • Manual/Auto Reset - Choose immediate restart or require manual intervention after trip
  • Direct Mounting - Mounts directly below corresponding contactor for compact installation

Technical Specifications

Model SeriesNR2
Current Range0.1A - 630A
Trip ClassClass 10 (Standard Motor Protection)
Protection FunctionsOverload + Phase Failure
Reset ModeManual / Automatic
MountingDirect mount on NC1/NC2/NXC contactors
StandardIEC 60947-4-1

FAQs

Q: How do I set the overload relay current?

A: Set the dial to match your motor's Full Load Current (FLC) as shown on the motor nameplate. For example, if motor FLC is 12A, set relay to 12A. The relay will trip at approximately 105-120% of this setting.

Q: What's the difference between NR2 and NXR series?

A: NR2 is the classic series with proven reliability. NXR offers enhanced features and modern styling while maintaining compatibility with Chint contactors.

Description

Chint original NR2 Overload Relay NR2-11.5 NR2-25 NR2-36 NR2-93 NR2-150 NR2-200 NR2-630 CHNT Thermal Overload Relay

   

Chint NR2 Thermal Overload Relay

 

General

1 Certificates: CE, KEMA, UL;
2 Electric ratings: AC 50/60Hz, 690V, 0.1A~630A;
3 Tripping class: 10A;
4 Mounting version:
   a. Plug-in: Available for NR2-11.5, 25, 36, 93, 150;
   b. Independent: Available for NR2-200, 630;
5 Standard: IEC/EN 60947-4-1

 

Features

1 3-phase bimetal
2 Continuously readjustable current settings
3 Temperature compensation
4 Tripping indicator
5 Test button
6 Stop button
7 Manual and automatic reset button
8 Electrically separated 1N/O plus 1N/C contact

 

Additional information
Current Setting Range (A)

0.1-0.16A, 0.16-0.25A, 0.25-0.4A, 0.4-0.63A, 0.63-1A, 1-1.6A, 1.25-2A, 1.6-2.5A, 2.5-4A, 4-6A, 5.5-8A, 7-10A, 9-13A, 12-18A, 17-25A, 23-32A, 28-36A, 30-40A, 37-50A, 48-65A, 55-70A, 63-80A, 80-93A, 80-104A, 95-120A, 110-150A
Model

NR2-11.5, NR2-25, NR2-36, NR2-93, NR2-150
Technical Datasheet & Downloads

📄 Technical Documentation & Product Specifications

Download official engineering datasheets, certified test standards (IEC / UL / CE), wiring diagrams, and dimensional drawings for Chint NR2 Thermal Overload Relay.

📥
Official Technical Datasheet (PDF) Complete electrical ratings, tripping characteristics, dimensions, and compliance specifications.
Request Official Datasheet (PDF)
📐
2D/3D CAD & Dimensional Drawings STEP, DXF, and PDF CAD drawing files for panel builders and switchgear designers.
Request CAD Model
Certified Standards: IEC 60898-1, IEC 60947-2, CE, RoHS, ISO 9001:2015
Manufacturer: Shanghai Newtrend Electric Co., Ltd. (Global Export Compliance)
Engineering Support: 24-hour response for custom voltage ratings, auxiliary contacts, and technical consulting.
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)?

A

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?

A

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?

A

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?

A

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?

A

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.

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