Function and Purpose
The NJBK7-800 series motor protector (hereinafter referred to as the protector) is suitable for AC motors with an AC frequency of 50Hz, rated insulation voltage up to AC690V or below, and a rated operating current of 1A-800A. It provides protection against overload, blockage, phase failure, three-phase imbalance, undercurrent, grounding, PTC temperature, communication failure, etc. The protector has an RS485 interface and a 4mA-20mA analog output interface, which allows networking communication and enables remote monitoring, control, and fault query of the motor through a host computer. For high current specifications, flexible Rogowski coils are used to collect current, offering advantages such as a wide set current range, high accuracy, and convenient installation. The protector is generally used in conjunction with AC contactors.
Detailed Parameters
| Parameter Category | Parameter Item | Parameter Value |
|---|
| 3.1 Main Parameters and Technical Performance | 3.1.1 Altitude | No more than 2000m. |
| 3.2 Ambient Air Temperature | -5℃~+40℃, and the average value within 24 hours does not exceed +35℃. |
| 3.3 Atmospheric Pressure | When the highest temperature is +40℃, the relative humidity of the air does not exceed 50%. At lower temperatures, higher relative humidity is allowed, for example, at +20℃, the air humidity can reach 90%. For occasional condensation caused by temperature changes, special measures should be taken. |
| 3.4 Pollution Level | Level 3. |
| 3.5 Inclination of Installation Surface from Vertical | No more than +5°. |
| 3.6 Explosive Hazard Medium | In places without explosive hazard medium, and where there are no gases or considerable conductive dust that can corrode metal and damage insulation. |
| 3.7 Equipment Exposed to Rainfall and Places Not Fully Filled with Steam | In places with equipment exposed to rainfall and where the equipment is not fully filled with steam. |
| 3.8 Places Without Significant Vibration, Impact, and Vibration | In places without significant vibration, impact, and vibration. |
| 3.9 Installation Category | Category III. |
| 3.10 Enclosure Protection Level | IP20. |
