low voltage motor protection relay

Low voltage motor protection relay is a series of protective devices developed for the fault when the low voltage motor is used, set the protection device with protection, measurement, control and communication in one.the protection device collects three-phase current, three-phase voltage, and calculate F, P, Q, COS, Se, Eq and other data,When the protection meet the action condition ,the output of the driving relay is driven to achieve the purpose of protecting the low voltage motor.

one.The 926MD description of protective relay protection for low voltage motor

     major function  ：Start timeout, overload, broken phase, grounding, plugging turn protection, current imbalance, short circuit, under load, temperature, under voltage, over voltage, high frequency, low frequency and other related protection functions

 

     protected mode  ：in the process of starting , only start the timeout protection, broken phase protection, current imbalance protection, grounding leakage protection, short-circuit protection, after the completion of the start, the protection of the relevant inputs are put into operation

 

Two,the 926MD starting mode of low voltage motor protection relay

    Direct starting, bidirectional reversible starting, dual-speed motor starting, resistance reduction starting, star / 3D start, auto transformer starting, self-starting, restarting, external shutdown.Note: please indicate the start mode when ordering.

 

 

three． The 926MD main parameters of low voltage motor protection relay：

     working power supply  ：85~265V AC and DC general.

     range of application  ：Suitable for AC 50Hz(60Hz Instructions for ordering)，500kW and below the motor。

     busbar voltage  ：when alternating voltage is Less than 660V，Direct access to the voltage input or through the PT connected to the voltage input 

  

   Communication status：RS-485 communication，ModBus Agreement

     Digital Input /digital output：9  input acquisition,4  relay exit.

      Digital Input  input supply internal power supply（External do add power， otherwise blame by yourself）。

      digital output ：AC250V/5A, DC 30V/5A.

      DC output：1 way 4-20mA can choose output（Normal without the need to order, please note）

      Event record: can record at least 50 event trip record information.

      Installation method: using standard DIN guide rail installation or screw fixed installation in two ways

      Attention: 500kW above the low voltage and low voltage motor protection relay uses: 9431D motor protection control device。

 

four. The 926MD Description of protective relay selection for low  voltage motor：

    when the 926MD rated current of low voltage motor protection relay  is within 200A,use the Low voltage motor protection relay with current transformer ,do not need to match CT: when the rated curent is above 200A,use external current transformer,The  CT two current is 5A,The CT two side 5A current signal is connected to the three-phase current input hole of the protection mutual inductor.CT ratio set in 

the internal low voltage motor protection relay . 

     five．The 926MD Composition and structure of low-voltage motor protection relay    

     The low voltage motor protection relay is composed of three parts.：LCD show ,Controller (connection) and external transformer.

 

six．The 926MD Interference performance of low voltage motor protection relay：

     Can withstand the III standard IEC1000-4-2 level, test voltage 6kV electrostatic discharge test.

     Can withstand the IEC1000-4-3 standard III level, dry meat field strength 10V/m radiated electromagnetic field interference test.

     Can withstand the III standard IEC1000-4-4 and fast transient interference test.

     Can withstand the III standard IEC1000-4-5 level surge test.