CHNT NR4-G Series Thermal Overload Relays
CHNT NR4-G series thermal overload relays are matched protective devices for medium and large AC contactors. They deliver reliable overload and phase-loss protection for three-phase asynchronous motors, equipped with wide adjustable current ranges, stable bimetallic tripping characteristics and independent split installation structure. Cooperate with NC1, NC2, CJX series contactors to assemble complete motor starter units for all kinds of heavy-load motor control cabinets.
Model Parameters & Features Table
| No. | Model | Category | Key Features | Application |
|---|---|---|---|---|
| 1 | NR4-63G 1-1.6A | Split Thermal Overload Relay | Frame 63A, adjustable current range 1~1.6A, built-in phase loss protection | Micro low-power auxiliary motor, small precision equipment protection |
| 2 | NR4-63G 1.6-2.5A | Split Thermal Overload Relay | 63A frame, setting range 1.6~2.5A, manual reset mode | Small conveyor, light-duty fan motor overload safeguard |
| 3 | NR4-63G 2.5-4A | Split Thermal Overload Relay | Adjustable 2.5~4A, anti-vibration bimetallic strip | Mini water pump, packaging auxiliary small motor protection |
| 4 | NR4-63G 4-6A | Split Thermal Overload Relay | Current range 4~6A, sensitive overload tripping curve | Injection molding small unit three-phase motor matching |
| 5 | NR4-63G 5.5-8A | Split Thermal Overload Relay | 5.5~8A adjustable segment, low temperature drift design | Workshop conventional small mechanical equipment motor |
| 6 | NR4-63G 7-10A | Split Thermal Overload Relay | Setting range 7~10A, dual manual/automatic reset optional | Medium-power ventilation and circulation pump protection |
| 7 | NR4-63G 9-13A | Split Thermal Overload Relay | 9~13A adjustable range, long service life conductive parts | Multi-station small automation production line motors |
| 8 | NR4-63G 12-18A | Split Thermal Overload Relay | 12~18A medium current segment of 63 frame | Medium small mixing and stirring machinery overload protection |
| 9 | NR4-63G 17-25A | Split Thermal Overload Relay | 17~25A, stable full-load long-time operation | Small air compressor, refrigeration auxiliary motor safeguard |
| 10 | NR4-63G 23-32A | Split Thermal Overload Relay | Adjustable 23~32A, fast phase loss cut-off response | Medium-power factory main branch motor control circuit |
| 11 | NR4-63G 30-40A | Split Thermal Overload Relay | 30~40A current range, thickened wiring terminals | Large fan, water pump unit overload safety protection |
| 12 | NR4-63G 37-50A | Split Thermal Overload Relay | 37~50A heavy current segment, high heat-resistant housing | HVAC central air conditioning unit motor matching |
| 13 | NR4-63G 48-63A | Split Thermal Overload Relay | Max adjustable range of NR4-63G frame 48~63A | Medium heavy-load processing equipment main motor protection |
| 14 | NR4-180G 55-80A | Split Thermal Overload Relay | Frame 180A, low current range 55~80A, split independent base | Large workshop medium-power heavy-duty motor safeguard |
| 15 | NR4-180G 63-90A | Split Thermal Overload Relay | 63~90A adjustable segment, wide current adjustment dial | Pump station large circulation water pump motor protection |
| 16 | NR4-180G 80-110A | Split Thermal Overload Relay | 80~110A, strong overload impact resistance | Mine auxiliary equipment, metallurgy medium-power motors |
| 17 | NR4-180G 90-120A | Split Thermal Overload Relay | 90~120A medium range, stable continuous tripping performance | Large refrigeration unit, chemical industry equipment motor |
| 18 | NR4-180G 110-135A | Split Thermal Overload Relay | 110~135A high current segment, reinforced conductive pole | Factory centralized heavy-load production line motor control |
| 19 | NR4-180G 120-150A | Split Thermal Overload Relay | 120~150A, large wiring terminal space for thick cables | Construction engineering large water pump overload protection |
| 20 | NR4-180G 135-160A | Split Thermal Overload Relay | 135~160A heavy-duty range, high precision bimetallic strip | Large air compressor, mixing main motor safety device |
| 21 | NR4-180G 150-180A | Split Thermal Overload Relay | Max adjustable range of NR4-180G frame 150~180A | Super large industrial heavy three-phase asynchronous motor |
Product Overview
CHNT NR4-G series split thermal overload relays include two frame sizes: NR4-63G and NR4-180G. The current coverage ranges from 1A up to 180A, perfectly matched with NC2 large current AC contactors and high-current control main circuits.
Different from integrated buckled thermal relays, NR4-G adopts split independent installation structure, separated from contactor body, suitable for large current heavy industrial control cabinets with high heat dissipation requirements. Each model is equipped with an adjustable current dial, allowing users to set protection value according to the actual rated current of the motor. Built-in sensitive phase-loss protection function, which can rapidly disconnect the control loop once three-phase imbalance or phase loss occurs, effectively preventing motor winding burnout.
Two reset modes are optional: manual reset for high-safety equipment requiring on-site inspection after fault tripping; automatic reset for unattended circulating equipment. Standard NO and NC auxiliary contacts are reserved for connecting indicator lights and PLC fault signal feedback circuits.
The whole series complies with GB/T 14048.5 national standard, with low temperature rise, stable tripping characteristic and strong anti-electromagnetic interference ability. Widely applied in metallurgy, mining, chemical industry, water supply & drainage, large HVAC, heavy machinery manufacturing and other fields, providing long-term reliable overload and phase-failure safety protection for medium and high-power three-phase motors.
CHNT NR4-G Series Thermal Overload Relays
