NJJ3 Counting Relay

Name: CHINT NJJ3 Electromagnetic Counting Relay
Brand: CHINT
SKU: NJJ3

Description

Product Overview

Digital counting relay for AC/DC control circuits, addition/subtraction/reversible counting

Main Features

Designed for industrial automation and control systems
Reliable performance and long service life
Easy installation and operation
LED display for clear indication

Technical Specifications

Parameter	Specification
Function	Counting and counting control
Frequency	AC 50Hz/60Hz
Voltage	AC/DC up to 240V
Standards	IEC 60947-5-1
Counting Modes	Addition, Subtraction, Reversible
Memory	Non-volatile, >10 years

Typical Applications

Industrial automation systems
Production line control
Machinery and equipment monitoring
Process control systems

Ordering Support

For detailed ordering information and technical support, please contact our sales team.

Product Catalog

Please refer to the catalog images below for detailed specifications:

Technical Datasheet & Downloads

📄 Technical Documentation & Product Specifications

Download official engineering datasheets, certified test standards (IEC / UL / CE), wiring diagrams, and dimensional drawings for CHINT NJJ3 Electromagnetic Counting Relay.

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

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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.