MEWOI-S903 3phase relay protection test set,Microprocessor Protection 3Phase Relay Tester

MEWOI-S903 3phase relay protection test set,Microprocessor Protection 3Phase Relay Tester

  • Main Features:: 1. AC current source (3 * 30A),2. DC current source:0--± 10A,3. AC voltage source,4. DC voltage source,5. switching value terminal

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1Meet all test requirements on site.The instrument has standard four phase voltage and three-phase current output. It can test not only various traditional relays and protection devices, but also various modern microcomputer protections, especially for transformer differential protection and standby automatic switching device. The test is more convenient and perfect.

2All kinds of technical indexes fully meet the standard of DL / t624-1997 "technical conditions for microcomputer based test device of relay protection" issued by the Ministry of electric power.
3Classic Windows XP operation interface, friendly man-machine interface, easy and fast operation; high performance embedded industrial control computer and 8.4 inch resolution 800 × 600 TFT true color display screen, can provide rich and intuitive information, including the current working state of the equipment and various help information.
4This Windows XP system has its own recovery function to avoid system crash caused by illegal shutdown or misoperation.
5Equipped with ultra-thin industrial keyboard and photoelectric mouse, it can complete all kinds of operations through keyboard or mouse just like ordinary PC.
6The main control board adopts DSP + FPGA structure and 16 bit DAC output. It can generate 2000 high density sine wave per week for fundamental wave, which greatly improves the quality of waveform and the accuracy of the tester.
7The high fidelity linear power amplifier ensures the accuracy of small current and the stability of large current.
8USB interface is used to communicate with PC directly without any connecting line, so it is convenient to use.
9. Can be connected to laptop (optional) to run. Laptops and industrial computers use the same set of software, so there is no need to relearn the operation method.
10.It has the function of GPS synchronization test. The device can be built-in GPS synchronous card (optional) and connected with PC through RS232 port to realize synchronous test of two testers in different places.
11. Equipped with independent dedicated DC auxiliary voltage source output, the output voltage is 110V (1a), 220V (0.6A).It can be used for relays or protection devices that need DC power supply.
12.It has the function of software self calibration, which avoids opening the case to calibrate the accuracy by adjusting the potentiometer, thus greatly improving the stability of accuracy.


1.    AC current source (3 * 30A)

Single phase current  output (RMS)

0 -- 30A / phase,  accuracy: 0.2% ±  5mA

Three phase parallel  output (RMS)

0 -- 90A / three  phase in phase parallel output

Allowable working  value of phase current for a long time (effective value)


Maximum output power  per phase


Maximum output power  of three phase parallel current


Maximum output  allowable working time of triple parallel current


frequency range

0 -- 1000Hz,  accuracy 0.001Hz

Harmonic number



0--360The accuracy is 0.1 degree

2. DC current source

DC current output

0--± 10A / phase, accuracy: 0.5% ± 5mA

3. AC voltage source

Single phase voltage  output (RMS)

0 -- 120V / phase,  accuracy: 0.2% ±  5mv

Line voltage output  (RMS)


Phase voltage / line  voltage output power


frequency range

0 -- 1000Hz,  accuracy: 0.001Hz

Harmonic number



0--360Degree, accuracy: 0.1 degree

4. DC voltage source

Single phasevoltage  output amplitude

0--± 150V, accuracy: 0.2% ± 5mv

Output amplitude of  line voltage


Phase voltage / line  voltage output power


5. switching value terminal

Switch input  terminal


Air contact

1 -- 20 mA, 24 V,  internal active output of the device

Potential reversal

Passive contact: low  resistance short circuit signal

Active contact:  0-250V DC

Switch output  terminal

4Yes, no contact, breaking capacity: 110V / 2a, 220V /  1a

6. others

Time frame

1ms -- 9999s,  measuring accuracy: 1ms

Volume and weight of portable series single machine

Volume 328 x 168 x 250mm3, about 12.5kg

Power Supply


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