At present, the energy efficiency level of distribution transformers, transformer DC resistance testing, transformer ratio group testing, and transformer insulation resistance testing are common testing items for transformer power outage maintenance. To complete the above tests and operations, it is necessary to separately configure transformer energy efficiency level instruments, transformer DC resistance testers, transformer ratio group testers, and transformer insulation resistance testers. Four types of instruments need to be carried during each test.  


Wuhan Kaidi Zhengda Electric Co., Ltd. has developed a four in one distribution transformer testing system powered by large capacity lithium batteries (direct resistance+transformation ratio+insulation resistance+energy efficiency level). We only need one set of equipment to complete the testing of four projects without the need for frequent disconnection of testing wires.

1. One wiring can complete direct resistance testing and variable ratio testing.
2. Direct resistance testing function, which can be used to test Yn, Y, and △ windings in three-phase automatic mode and calculate the three-phase unbalance rate; The maximum output current is 20A, which can meet the testing of low-voltage coils of distribution network transformers.
3. Variable ratio testing function, with testing functions for three-phase, single-phase, and Z-type transformers; PT/CT ratio and polarity testing functions; Blind testing function.
4. Energy efficiency rating function, with capacity, load, no-load, and zero sequence impedance testing functions.
5. Insulation resistance testing function, maximum output short-circuit current of 5mA, and adjustable from 1mA to 5mA. It has the functions of insulation resistance IR, absorption ratio DAR, and polarization index PI testing.
6. It has multiple wired and wireless communication interfaces, which facilitate the expansion of instrument functions.
7. The instrument adopts an embedded Linux operating system, which has high security, smoothness, and ease of use.
8. The instrument adopts an A7+M4 dual core architecture, which meets both real-time measurement and smooth operation requirements.
9. Industrial grade 7-inch large screen display, with a fresh and simple display style design, fully touch combined with one click shuttle operation, creating a comfortable and convenient human-machine interaction experience for you.
10. This instrument is powered by a large capacity lithium battery and comes with a built-in charger.

 

Direct resistance test
Output current: 20A, 10A, 5A, 1A, 0.1A, ≤ 10mA
Measurement range:
20 A gear 0.5m Ω～ 100m Ω 10 A gear 1.0m Ω～ 300m Ω
5A gear 10 m Ω～ 1.0 Ω 1A gear 200m Ω～ 6.0 Ω
0.1A gear 2.0 Ω～ 60 Ω≤ 10mA gear 30 Ω～ 50 k Ω
Accuracy: ± (reading x 0.2%+2 words)

 

Variable ratio test
Measurement range: 0.9 to 10000
Accuracy:
± (reading x 0.1%+2 words) (less than or equal to 500)
± (reading x 0.2%+2 words) (greater than 500 but less than or equal to 3000)
± (reading x 0.3%+2 words) (greater than 3000)
resolving power:
0.9～9.9999(0.0001) 10～99.999(0.001)
100～999.99(0.01) 1000～9999.9(0.1)
10000 and above (1)

 

Capacity and empty load testing
Measurement range:
Voltage AC 50V~850V
Current AC 0.5A~100A
Capacity 30kVA~65000kVA
Accuracy:
Voltage and current: ± (reading x 0.2%+2 words)
Power (0.2 ≤ cos π≤ 1): ± (reading x 1.0%+2 words)
Capacity: ± (reading x 10%+2 words)

 

Insulation resistance test
Output voltage: 500V, 1000V, 2500, 5000V optional
Short circuit current: 1mA~5mA optional
Current testing range: 10mA
Accuracy of current testing: ± (reading × 5%+0.2nA)
Capacitance test range: 20 μ F
Accuracy of capacitance test: ± (reading × 15%+0.03nA)
Capacitor discharge rate: from 10000V to 10V, 0.5s/μ F

 

Usage conditions and appearance
Working power supply: built-in lithium battery, capacity 11AH
Charging voltage: AC220V
Operating temperature: -10 ℃ to 50 ℃
Relative temperature: ≤ 90%, no condensation
Weight: 12kg
Size: 438 × 318 × 190 (mm)