1.To do a good job in the maintenance of the distribution box, it is necessary to fully understand the laying mode, structural layout, route and starting end position of power supply line control circuit. Switch cabinet is an electrical equipment. The external line of the switch cabinet enters the main control switch in the cabinet first, and then enters the sub control switch. Each branch circuit is set according to its needs. For example, instruments, automatic control, motor, magnetic switch, various AC contactors, etc., some of them are equipped with high-voltage room and low-voltage room switch cabinet, with high-voltage bus, such as power plant, and some are also equipped with low cycle load shedding to ensure the main equipment. According to the electrical wiring, the switchgear, measuring instruments, protective electrical appliances and auxiliary equipment are required to be assembled in closed or semi enclosed metal cabinet or on the screen to form a low-voltage distribution box. In normal operation, the circuit can be connected or disconnected by manual or automatic switch. The power cabinet is a combination of electrical control cabinets that provide power for the normal operation of the whole machine, including fuses, circuit breakers, contactors, frequency converters, high-voltage cabinets, transformers, etc. And should carry out a weekly inspection circuit, check and monitor the distribution box load size and heating. In case of heavy rain, flood and other special circumstances, the inspection frequency shall be increased temporarily.

2.Railways, along underground cable roads, are inspected every half a month. Check the cable head end, cable trench and cable throwing to see if there is ground collapse pit, with or without excavation trace, and the mark pile is intact. Diagnosis, distribution transformer separation position rationality diagnosis. The reactive functional operation simulation device shall be able to compensate the value or simulate the switching operation history data of the capacitor respectively through the difference compensation device, so as to determine the more reasonable value position for the operation of the automatic device which is reasonable for the distribution transformer. User quality analysis module voltage includes pass rate calculation, harmonic analysis, and voltage unbalance analysis of voltage. The calculation of voltage qualification rate shall include: each phase and three-phase synthesis, monthly, quarterly and annual accumulated time limiting voltage and cumulative time limiting voltage, voltage qualification rate, date of maximum voltage and minimum voltage value. Output voltage unbalance and harmonic analysis are used to analyze: phase and three-phase voltage and current waveforms and spectra, voltage and current distortions, negative sequence voltage components, unbalance. This may give the user load point, quarterly and annual cumulative customer outage (planned outage and outage failure) and duration of power supply reliability analysis. The reliability analysis of transformer equipment gives the fault isolation switch and load switch of accumulated electrical equipment shutdown and integrated maintenance downtime, failure rate and reliability rate, total number of overload and time, maximum load lasting for a period of time, cumulative operation time, equipment life consumption.