NJBK8 Motor Protector

Product category:
Protection Relay
Product code:
P-517
Model:
NJBK8

Function & Use (Application Scenarios)

Relays, protective relays products are mainly applicable to the NJBK8 series motor protector (hereinafter referred to as the protector), a multifunctional comprehensive motor protector. Applicable to AC frequency 50Hz/60Hz, rated insulation voltage up to AC690V or below, rated

Surprise on inquiry

Product highlights

  • Smart Communication Support
  • Modular design
  • Accurate meter monitoring
  • Control response is stable
  • Engineering Application Compatibility

Model

NJBK8

Main Product Parameters

CategoryRelay Protection and Automation DevicesSecondary CategoryProtective Relay
ParametersRated current specifications (A): 05, 20, 40, 100, 300, 800; Rated operating voltage Ue (V): AC220V~440V or AC380V~690V (H type); Rated control circuit power supply voltage Us (V), frequency (Hz): AC110V~AC240V, 50Hz/60Hz; DC110V~DC350V

Product details

Function and Application

The NJBK8 series motor protector (hereinafter referred to as the protector) is a multifunctional integrated motor protector. It is suitable for AC motors with an AC frequency of 50Hz/60Hz, rated insulation voltage up to AC690V, and rated operating current of 1A~800A (the 5A specification can be expanded to 2000A) that operate continuously or intermittently. It integrates protection, measurement, control, communication, and maintenance, and can meet various application scenarios. Its comprehensive protection functions ensure the safe and stable operation of the motor. The product adopts a modular design concept, and users can select and customize functions according to their needs to adapt to various application scenarios.

Detail Description

Parameters:
Rated Current Specifications (A): 05, 20, 40, 100, 300, 800
Rated Operating Voltage Ue (V): AC220V~440V or AC380V~690V (H type)
Rated Control Circuit Power Supply Voltage Us (V), Frequency (Hz): AC110V~AC240V, 50Hz/60Hz; DC110V~DC350V

Detailed Parameters

Parameter ClassificationParameter ItemParameter Value
4.1 Rated Control Power Supply Voltage of the ProductAC110V~AC240V, 50Hz/60Hz; DC110V~DC350VMain Circuit: Rated Insulation Voltage AC690V, Rated Frequency 50Hz, Rated Impulse Withstand Voltage 1.2/50µs, 4kV
Rated Short-Circuit Current Limit (KA)125
Rated Insulation Voltage UI VAC690
4.2 Basic Parameters of the Auxiliary CircuitContact Number3 Normally Open Contacts, 1 Normally Closed Contact
Rated Thermal Current Ith AAC-15: 1.5, ACa15: 0.47, DC13: 1
Usage CategoryAC240, AC415, DC30
Rated Operating Voltage Ue VAC240, AC415, DC30
Rated Operating Current Ie AAC240: 1.5, AC415: 0.47, DC30: 1
Rated Insulation Voltage UI VAC415, DC30
Rated Impulse Withstand Voltage Uimp (1.2/50 µs) kV2.5
4.3 Product Functions are shown in Table 3.Basic Protection FunctionsInverse Time Overload Protection, Thermal Memory Function, Underload Protection, Locked Rotor Protection, Blockage Protection
Extended Protection FunctionsTimed Overload, Short Circuit, Phase Failure, Current Unbalance, Over Power, Under Power, Current Overflow, Phase Sequence, Overvoltage, Undervoltage, Start-up Timeout, Start-up Overfrequency, External Fault, Leakage, Grounding
Parameter MeasurementThree-phase Current, Three-phase Voltage, Demand/Earthing, Power, Energy Metering
Other FunctionsRTC Clock, Event Recording, RS485 Communication, 6DI, 4DO DO
4.4 Structural FeaturesThe main unit uses a panel-mounted installation method, and the current transformer uses a rail-mounted or assembled installation method. Plug-in terminal blocks facilitate user wiring. Multiple current specifications are available to meet different power motors. It has a programmable 4mA~20mA analog output function. Multiple DO outputs facilitate complex motor control.
4.4.1 Set all protection parameters using the buttons.
4.4.2 TFT LCD screen displays three-phase current, voltage, power true etc. electrical parameters and fault related information.
4.4.3 LED light indicates the working status of the protector (start, operation, stop, fault).
4.4.4 Supports button, DI input, and communication control for motor start and stop simultaneously.
4.4.5 Current transformers use a rail-mounted or assembled installation method.
4.4.6 Plug-in terminal blocks, convenient for user wiring.
4.4.7 Multiple current specifications are available to meet different power motors.
4.4.8 It has a programmable 4mA~20mA analog output function.
4.4.9 Multiple DO outputs facilitate complex motor control.

Requirement confirmation

Application, rating, quantity and drawings are checked first.

Factory matching

Supplier capacity, certificates and production slot are reviewed.

Order transaction

Confirm commercial terms, sign the commercial contract, and confirm the related document checklist.

Shipment control

Packing photos, inspection records and delivery status are tracked.