HCL 2508 (200A) Circuit Resistance Tester

Overview

        The conductivity performance of the conductive circuit of the breaker (hereinafter abbreviated as switch) plays an important role in ensuring safe operation of the switch. The conductivity performance can be reflected by the resistance of the conductive circuit. Therefore, it is specified in IEC standards and by the manufacturer that circuit resistance shall be measured. What’s more, clear indexes are given to all types of switch circuits. Generally speaking, the double arm electric bridge was used in the past. Because the voltage and current of the electric bridge are very low, the distribution of testing data is great when there is impurity between movable contact and static contact of the switch or there is surface oxidation etc. And the anti-interference of the electric bridge is bad at same time. This instrument manufactured by our company is extensively used to measure contact resistance, circuit resistance of various electrical switches and contact resistance of cable and wire, welding seam.

Technical parameters

1. Testing current: 50A, 100A and 200A;

 2. Range of measuring:        
                 0 - 100 mΩ, at 50A

                 0 - 20 mΩ, at 100A

                 0 - 4mΩ, at 200A

3. The minimum resolution: 0.1μΩ

4. Accuracy:  0.5%±0.2µΩ

5. Output voltage: DC10V    

6. Duty: continuous type

7. Power supply: AC220V±10％ at 50Hz±1Hz

8. Power consumption: ≤1000W

9. Operation temperatures: -20℃ - 40℃

10. Relative humidity：≤80%, without condensation

11. Weight: 8..7kg

12. Size: 350mmx230mmx260m

Performance and features

1．The testing current is high enough to fully meet the requirements indicated in the national standards for testing of contact resistance;

2．A high output voltage, a wider measuring span up to 100MΩ;

3．The test current is supplied by a high precision, switching type current constant power supply (200A), and therefore with no needs to be adjusted, so that a fast and accurate measurement can be provided.    

4．Wiring through four terminals effectively eliminates impacts on the test results caused by the resistance of test wires;  

5．The product provides faster test, indicating results 5 seconds or so after test start-up;

6．The product equipped with over-heat protection circuit can be continuously work for a long time and therefore provides high reliability and stability;   

7．The product is an easy operation, lightweight type and applicable to field use.

Operating Method and Test
Firstly, connect the specified test wires in accordance with the color (red to red, black to black), the coarse current wire is connected to the I+, I- columns and twist tightly, the thin voltage wire is connected to V+,V- columns and twist tightly; secondly, use two tongs to clamp two ends of the test object.(See Figure 1)

Note: All connection surfaces of test clamp should be reliably contacted with the test object. 

Question 1:
When measuring, the resistance value displays too large or at 1 (over the range)on the circuit resistance tester.  How to solve it?

Answer: 
Check whether the measured resistance value is too big;
Check whether the voltage input lines are connected inside the output current lines;Check whether the voltage output lines are well connected and tested joints are oxidized.