Product Overview: The 239 relay is designed to protect three-phase AC motors with a variety of protection functions and can be connected to a central control/monitoring system. It monitors phase currents, is suitable for motors of various voltages, and has a variety of optional features such as RTD monitoring, analogue outputs, etc. It is certified for use in many industrial environments. The product is certified for use in a variety of industrial environments.

Installation guide: Installation requires cutting holes in the panel according to the size and fixing with screws. Check the product label to confirm configuration and options before installation. External connections include control power, CT inputs, output relays, etc. Different connections have different requirements and require attention to grounding and insulation. There are also specific precautions for performing dielectric strength tests.
Operating instructions: Operation is via the front panel, which consists of keys, display and status indicators. The keys are used to select information, set parameters, etc.; the display can show a variety of information; and the status indicators reflect the operating status of the relay.

Programming settings: Setting points can be input through the front panel, RS485 port and computer or SCADA system connection. The setting content covers system configuration, protection function, output relay and so on, and different setpoints have different functions and value ranges.

Monitoring Function: It can monitor various operating parameters of the motor in real time, such as current, temperature, load, etc.. It can also view fault records, statistical data, etc., which is convenient for evaluating the motor running status and troubleshooting.
Specification Parameters

Current-related parameters: phase current input supports 1A and 5A sub-range, range 0.1 – 11×phase CT primary, accuracy ±2% of full scale; ground current input is divided into 5A sub-range and 50:0.025, with different accuracy for different ranges. There are 15 types of overload curves, overload pickup suppression 1.00 – 5.00 x FLC, pickup level 1 – 1500A. Short-circuit and earth tripping, circuit breaker failure, etc. have corresponding current setting ranges and time delay settings.

Other electrical parameters: Support multiple voltage control power supply, 90 – 300VDC/70 – 265VAC is standard, 20 – 60VDC/20 – 48VAC (MOD 501) is also optional. Communication interface is RS485, 2-wire half-duplex isolated, baud rate 1200 – 19.2kbps, Modbus RTU protocol. Analogue output can be selected from 0 – 1mA, 0 – 20mA, 4 – 20mA, different ranges correspond to different load capacity, accuracy ±2% of full scale reading.

Advantages
Comprehensive protection: It provides all-round protection for the motor, covering overload, short-circuit, blocking, under-current, unbalance, ground fault, overheating and other types of faults. For example, in overload protection, 15 optional curves can accurately match the thermal characteristics of the motor, effectively avoiding damage to the motor due to overload.

Convenient communication and monitoring: Equipped with RS485 communication interface, it can be connected to the central control/monitoring system to achieve remote monitoring, set point programming and fault diagnosis. At the same time, it can monitor various parameters of the motor in real time, such as current, temperature, running time, etc., which is convenient for the operator to grasp the running status of the motor in time.

Strong adaptability: it can be adapted to motors with various line voltages, and protection is achieved by monitoring the phase current through the current transformer. A variety of control power supply options, wide temperature operating range and high altitude adaptability, so that it can work stably in different industrial environments.