Okay.
1. The air duct cloth roof has very good flame retardant and antistatic properties, and also has strong strength and ventilation performance, which can ensure a long service life.
2. There are many different models of dryer cloth. Its performance is guaranteed and it is reliable for long-term use. It can reduce rainwater infiltration on the roof, so it is better to pave the roof with dryer cloth.
Mining equipment grounding devices are usually tested once a year. This is a common practice for equipment and devices. For specific reference standards, please refer to local standards, such as: DB37/-7 32h-2018 Mine Power Supply Grounding Test Specification
In fact, as a safety manager, the sensitivity of safety is not limited by the inspection period. Only in this way can we do Put safety first. For example. How often should safety helmets be inspected? Are the car's brakes only inspected once at the end of the year? What about seat belts? What about the extended leakage protection device? What about lightning protectors?
In many cases, electricians need to develop a good habit. During maintenance, they can make a rough judgment by measuring the phase, ground voltage and phase zero voltage.