The grounding resistance tester under UHV power can help many power workers conduct various power tests more conveniently.

Introduction and Application of DC System

In the power system, the DC system is a separate power supply part that is not affected by other electricity consumption, and its significance is also very important. The DC system consists of charging equipment, batteries, DC screens, DC sub screens, insulation monitoring devices, and loads. The main function is to provide DC power equipment for signal equipment, protection, automation equipment, emergency lighting, emergency power supply, circuit breaker opening and closing operations. Common DC systems include 24V, 36V, 48V, 110V, and 220V., In addition, there are some very common voltage levels.

The hazards of grounding in DC systems

The harm caused by grounding the DC system is self-evident. We all know that the power system operates in a flat state, and protective devices play a crucial role in data acquisition, monitoring, and subsequent hardware processing. The biggest hazard of grounding a DC system is the possibility of causing relays. Electrical protection, signals, automatic devices, etc. may malfunction, refuse to operate, trip, etc., which is what we often refer to as' inaction without action 'or' inaction without action without action '. In this case, once the power system loses its protective power source, it may cause widespread paralysis of the power system, and fault warning processing must be carried out to prevent the DC system from grounding operation.

How to deal with grounding faults in DC systems

The processing of DC systems requires the use of dedicated testing equipment for DC grounding fault testers, using the "waveform analysis method", which can accurately search without affecting system operation under uninterrupted power supply. The DC system fault tester consists of a signal generator and a signal receiver. It consists of three parts: a signal collector (caliper). When searching for faults in the DC system, the three must be used in conjunction. The specific solution is to insert the signal output lead into the signal generator, clamp the bus with the red clamp, and determine the signal with the black clamp. After the generator is connected correctly, turn on the power switch of the signal generator, and connect the signal generator to the busbar and the ground wire near the battery output end according to the grounding fault of the DC system. To improve detection accuracy, the signal generator can be connected to the DC fuse socket at the beginning of the branch closer to the fault area, or to the small DC bus below the circuit. During the detection process, the signal generator should always be connected to direct current. The power supply end of the branch, fault detector, and clamp meter are always tested at the load end of the DC branch, and the display results are displayed on the display panel.

Preventive measures

1. Due to the precision nature of the equipment, it should be handled with care during transportation, use, and storage. Components should be protected from strong vibrations such as falling or falling.

2. The signal source should be added between the faulty bus and ground.

3. The clamp caliper of the DC system grounding fault tester can only be used for DC circuits and cannot be used for AC circuits.

4. When there is no obvious grounding in each branch, pay attention to whether the grounding point is in the power supply part, such as the battery, charger, etc.

5. During the testing process, please turn off the power of the clamp meter and signal receiver when not in use to extend battery life.

6. When the power of the signal receiver is low, the battery should be replaced in a timely manner to improve the detection accuracy.

7. Due to the high sensitivity of the clamp gauge, do not hold it with your hands during testing. Keep the clamp gauge in a stationary state to avoid affecting the detection accuracy.