Intelligent protection and monitoring device for electric motors

product details

overview

The 800 motor intelligent protection monitoring device is a new type of motor protection and installation control device developed based on the latest microcomputer processing technology on existing motor protector products. This product has conventional motor protection and control functions, and has a more complete LCD Chinese display, making it more intuitive, convenient, and user-friendly to use.

This product adopts a modular design structure, with a small volume, compact structure, and easy installation. It can be directly installed and used in low-voltage control terminal MCC cabinets and various drawer cabinets of 1/4 unit and above.

This product supports DCS/PLC hard wired mode (DC4~20mA analog output, with 20mA corresponding setting current and alarm/protection signal output according to user needs) and RS-485 network communication mode, making it convenient for users to centrally control MCC.

The motor protection device integrates functions such as measurement, protection, control, interlocking, and communication, and can protect and control three-phase asynchronous motors and increased safety motors. It is an ideal product for motor protection in industries such as petroleum, chemical, coal, power, metallurgy, and municipal.

Product Features

★ It can accurately measure the operating current, voltage, etc. of the motor.

★ It can provide comprehensive protection for electric motors, including blocking, short circuit, leakage, imbalance (phase failure), starting timeout, overload, underload, overvoltage, undervoltage, PTC separation, etc.

★ It can achieve six starting modes for electric motors: direct start, direct bypass start, forward reverse start, forward reverse bypass start, star delta start, and autotransformer voltage reduction start.

★ Provides RS-485 communication function, 4~20mA analog transmission output function, can be connected to secondary instruments or computer systems, and supports custom protocols. MOD BUS-RTU and PROFIBUS-DP communication protocols.

★ With multiple programmable input/output interfaces, it can meet various process and control requirements.

★ Adopting high-performance microprocessor (MCU). Fast response speed, timely and reliable action.

The use of a switching power supply provides better stability, stronger anti-interference ability, wider operating voltage, and lighter weight.

★ Complete software and hardware design, with self checking and self calibration functions, high reliability and stability.

The overall appearance of the machine is compact and beautiful, and the installation method is flexible and convenient.

★ LCD Chinese display.

basic function

The motor protector is suitable for protecting and controlling three-phase asynchronous motors with AC 380V/660V, increased safety motors, and motors with variable frequency speed regulation. The rated current range of the main circuit motor is 0.1~400A.

Technical Parameter

This product is composed of a power module, a data processing module, an input/output module, and a sensor module. The modular design provides great convenience for product maintenance and upgrades. This product achieves the following functions: protection function, control function, measurement function, and network communication function.

Protection function

This device continuously monitors and provides real-time protection for three-phase current, supply voltage, leakage current, thermistor PTC resistance, analog input, and actual rotation during the start-up process. Various protection functions are independent of each other, allowing multiple protection functions to be triggered simultaneously, and the tripping instruction is discovered by the protection function that reaches the tripping condition first. Various protection functions can be set and adjusted according to the actual situation through the upper computer or control panel. All protection parameters are provided by customers or default at the factory, meeting the needs of traditional protection to more than 10 comprehensive protection functions.

Blockage protection

Severe blockage or overload operation of motor drive equipment is defined as locked rotor fault. When the ratio of three-phase current to rated current exceeds the locked rotor setting coefficient (4-8), start the locked rotor system (la/le>4&Ib/le>4&Ic/le>4) ●

Locking protection parameters:

Control function:

This product has two control modes for motor start stop: remote control and panel control, which can be set in the menu.

Panel control:

Panel control is controlled by the buttons on the operation display unit to directly control the start and stop of the motor. The "start" button corresponds to the start 1 mode, and the "stop" button stops the motor operation.

Remote control:

There are two forms of remote control: PC leg system and DCS control. When receiving the PC startup command, this device starts 10% of the motor as usual; When receiving a shutdown command from the PC, this device controls the relay button to shut down the motor. When a control terminal of DCS is closed, this device controls the motor according to the definition of the corresponding terminal (start 1, start 2, stop).

Measurement function:

This product performs AC sampling on three-phase current and adopts current frequency tracking technology and self calibration technology. The current measurement is accurate and rapid, with a measurement accuracy better than level 1, and a signal range of 10~55Hz,

Network communication function/DCS interface:

This product supports RS-485 network communication function and DCS/PLC hard wired mode (DC4~20mA analog output, alarm/protection signal output); Convenient for users to centrally control MCC.

Network communication function:

The physical layer of the network communication function complies with the RS-485 standard and supports MODBUS-RTU protocol and PROFIBUS-DP protocol.

DCS interface:

Status input: DCS start 1, DCS start 2, DCS stop.

Alarm/protection signal output: 4 programmable outputs.

Analog output: Programmable 4-20mA analog output (factory default is A-phase current), powered by 24VDC inside the device.

Switch input:

The rated capacity of the contacts is 5mA/24VDC. This device provides 6 switch inputs, all of which are passive contacts. The input stage adopts optoelectronic isolation circuits, and the signal power supply is 24VDC,

Provided internally by the device; This device detects input point rotation. When the detected current is greater than 2mA, the contact is defined as closed; When the detection current is less than 0.5mA, the connection is defined as

Point to disconnect.

4-20mA current output:

The physical layer of this device's communication complies with the RS-485 electrical standard, and communication protocols include custom protocol, MODBUS-RTU protocol, and PROFIBUS-DP protocol (optional).

MODBUS-RTU communication port configuration: baud rate 9600, parity check NONE, data bit 8, stop bit 2, start bit 1, communication address 0~255 can be set;

PROFIBUS-DP communication port configuration: baud rate adaptive, maximum data transfer rate of 12MBIT/S, communication address 0~126 can be set, TM.gSD file provided, hardware optoelectronic isolation.

Startup mode:

This device supports multiple startup modes: direct (soft start) startup, forward and reverse startup, and star delta startup. Please refer to "Typical Applications" for the startup schematic.

Direct (soft start) startup:

Direct starting is the basic starting method for motors. When a start command is received from the PC, DCS.I/0, or control panel, the control relay J2L output contact of this device closes and the motor starts.

Forward and reverse startup:

When receiving the forward start command (remote board control), control relay J2 to close by clicking, and the motor rotates forward; When receiving the reverse start command (remote board control), if the control relay "3" is closed, the motor will reverse.

Star Triangle Startup:

When the motor is in a star shape during startup, the starting current is only one-third of the delta connection, and the motor starts with star shaped voltage reduction. After the conversion time is up, Y - △ conversion is performed, and the motor runs in a delta connection. The conversion time should be less than the starting time, that is, the Y - △ conversion must be completed before the motor starts.

Typical applications:

Direct (soft start) startup:

Direct starting is the basic starting method for motors. When receiving a start command from the PC, DCS.I/0, or control panel, the J2 output contact of the control relay of this device will close and the motor will start; If the protection relay J1 is disconnected, fault protection will be executed. If the short-circuit relay J4 is closed, the air switch will trip. If the alarm relay J5 is closed, it will be used for alarm output. SB1 is the on-site start button, and SB2 is the on-site stop button.

Direct start control schematic diagram:

Note 1: When the motor le<100A, an external protective CT is not required; when the motor le>100A, an external protective CT is required, and the wiring of the CT can be found in Note 2;

Star Triangle Startup:

When receiving a start command from PC, DCS.I/0, or control panel, the J2 output contact of the control relay of this device closes, and the motor is connected to star start. The starting current is only one-third of the delta connection, and the star machine starts with star voltage reduction; After the conversion time, the output contact of control relay 2 is disconnected, and the input contact of control relay J3 is closed for Y - △ conversion. The motor operates in a delta connection. The conversion time should be less than the starting time, that is, the Y - △ conversion must be completed before the motor starts. When there is a star delta starting circuit on site, control relay J2 to close the starting motor by tapping the output contact; SB1 is the on-site start button, and SB2 is the on-site stop button. If the protection relay is disconnected, fault protection will be executed. The short-circuit relay J4 will close and the air switch will trip. The alarm relay J5 will close for alarm output.

Schematic diagram of star delta start control:

Note 1: When the motor le<100A, no external protective CT is required; When the motor le>100A, an external protective CT is required, and the wiring of the CT should refer to Note 2;