The failure of the meter box caused by the ambient temperature and the cause analysis
Although the weather has not reached the time of high temperature and extreme heat, different types of faults have occurred in the residual current action protector in the meter box, such as:
(1) The residual current action protector is faulty;
(2) The converter contactor is faulty;
(3) Failure of the metering energy meter;
(4) Faults caused by internal wiring;
(5) Burnout of the fuse base and burnout of the motor caused by the lack of phase, etc.
Wenzhou Mingdun Electric made an analysis on the failure problems caused by the influence of ambient temperature on low-voltage electrical appliances.
The fault caused by the influence of ambient temperature on the meter box
①Reactive power compensation capacitors and fuses operating at high temperatures will also shorten their life.
②The electronic products in the meter box, such as residual current action protectors and electronic meters, will seriously affect the service life of the products when they are operated at high temperatures, and will also affect the performance stability of the protector and the reliability of the action. Measurement accuracy.
③Various low-voltage electrical appliances, mostly A-class insulation, have a limit allowable temperature rise of 65°C during long-term operation. The high temperature in the meter box and the production of the meter control box make it difficult for the internal heat of the low-voltage electrical appliance to dissipate outwards during operation, so after a certain period of time, it will burn out due to insulation aging; the plastic insulated wire will also be broken down by thermal aging.
Reasons for meter box failure caused by ambient temperature
The low-voltage electrical appliances in the distribution box are composed of fuses, AC contactors, residual current action protectors, capacitors and electrical measurement digital meters. These low-voltage electrical appliances are designed and manufactured according to international standards, and their normal working conditions are specified accordingly: the upper limit of ambient air temperature does not exceed +40℃; the average value of ambient air temperature for 24 hours does not exceed +35℃; ambient air temperature does not exceed +35℃ The lower limit of the temperature is not lower than -5°C or -25°C.
In the high temperature and hot weather in summer, the low-voltage electrical appliances in the meter box will also generate heat themselves during operation. In addition, the external ambient temperature is high, and the temperature inside the box will reach +60 ℃ or more. At this time, the temperature is much higher than these electrical appliances. The ambient temperature specified in the specification will cause the failure of the meter box. Reducing the temperature of the meter box and making technical improvements to the meter box are the methods to reduce the failure of the meter box.