GE Multilin 239 Motor Protection Relay

GE Multilin 239 Motor Protection Relay

Performance Advantages

Comprehensive protection functions: Thermal overload (15 selectable curves), phase short-circuit, mechanical fault,

 thermal memory blocking, single-phase/current imbalance, earth fault (trip and alarm), over-temperature (via thermistor or optional RTD input), 

under-current, circuit breaker failure, etc., which can provide all-round protection for motors and related mechanical equipment, 

and effectively respond to all kinds of electrical and mechanical faults.

Compact and cost-saving design: The compact design reduces installation costs, which is more advantageous in space-constrained installation environments.

Flexible settings: With multiple setting groups, the protection and control parameters can be flexibly adjusted according to different application scenarios 

and motor requirements to meet diversified usage requirements.

Convenient testing: Built-in simulation function simplifies the testing process and facilitates testing and debugging of relays in the field, 

which reduces maintenance time and cost.

Powerful equipment monitoring: Real-time temperature monitoring through optional RTD input can detect motor overheating problems in time, 

and display status, current, temperature and other information, with fault diagnosis, trip records (the last 5 times) and other functions, 

so that operators can easily understand the operating condition of the equipment, and troubleshooting in time.

Convenient communication and upgrading: It supports Modbus RTU communication protocol, which is convenient for data interaction 

and remote control with other equipments; it can be upgraded on site by using flash memory, which can follow the pace of technological 

development and keep the advanced performance of the product.

Product Specification

Communication protocol: support Modbus RTU protocol, to ensure the compatibility and stability of communication with other devices.

Control power supply: DC control power supply input range of 90 - 300Vdc, can adapt to a variety of power supply environment.

Overload protection: Locked rotor start protection range is 0.5 - 11.0 xflc; overload curve trip time pickup level is 1 - 1500A.

Other accuracy specifications: Thermistor accuracy is ±5% or 100Ω (whichever is greater); unbalance accuracy is ±2%.

Switch input type: Dry contact switch input.

Physical Characteristics: Approximate shipping weight of 5 lbs. or 2.3 kg, compact design, fits most starters.

User Interface: RS485 serial interface, keypad, 40-byte backlit display, 6 LEDs, and compatibility with Enervista setup 

software for easy parameter setting, status viewing, and control.

Data format and rate

Data frame format: Asynchronous transmission data frame consists of 1 start bit, 8 data bits and 1 stop bit, total 10 bits.

Data Rate: Supports 1200, 2400, 4800, 9600 and 19200 baud rates.

Packet Format: Contains slave address, function code, data and CRC check code, the packet format of master request and slave response are similar.

Error checking: CRC-16 (16-bit Cyclic Redundancy Check) algorithm is used to check for transmission errors, 

if there is a checksum error, the slave will not respond.

Timing: The receiving device maintains packet synchronisation by measuring the time between character receipts. 

If no new character is received for more than 3.5 characters or the packet has not been received, the communication link is reset.

Supported Modbus Functions

Reading of set and actual values (function code 03/04): The set (‘Holding register’) and actual (‘Input register’) values of the relay can be read, 

up to a maximum of 125 registers at a time, with the data being transferred in two bytes, the lower byte first. 

The data is transferred in two bytes, with the lower byte first.

Execute operation (function code 05): The master can use this function to request the relay to perform a specific command operation, 

which corresponds to the command code in the memory map.

Storing a single setpoint (function code 06): the master stores a single setpoint in the relay memory and 

the slave response displays the entire master transfer.

Read device status (function code 07): Used to quickly read the status of the selected device, 

each bit of the returned status byte indicates different status information.

Loopback test (function code 08): Used to test the integrity of the communication link, the relay displays the request.

Storing multiple setpoints (function code 16): multiple setpoints can be stored in the relay memory, 

Modbus allows up to 60 holding registers to be stored at one time, the slave response will display the relevant information.