Working Principle and Model of Electric Meter (5)

What are the common faults of the electric meter?

1. There is a burnt smell in the bakelite junction box

Reason 1: When installing or replacing the circuit wires, the fixing screws in the box are not tightened. When the electrical load increases, the screw posts heat up due to poor contact, which burns the bakelite box and produces a burnt smell.

Solution: After removing the terminal cover of limb surgery, pull down the main switch knife, remove all the power wires, scrape the residue of the wire head with the knife again, put it into the terminal post, and tighten all the screws to eliminate the fault.

Reason 2: The quality of the wires connected to the electric meter from the indoor is poor, which causes an oxide layer between the copper column and the wire, especially the electric meter installed in a humid and unventilated place is prone to such problems. Thus increasing the resistance value makes the contact point heat up and damages the junction box.

Solution: The oil in the junction box should be completely removed and the wires should be replaced. Sometimes when the electrical equipment exceeds the actual ampere value of the meter, not only the junction box will be damaged, but the meter may also be destroyed by strong current. Therefore, when it is found that the rated current of the meter is very different from the total load of the actual electrical appliances used, the use time should be staggered or the watt-hour meter should be replaced to prevent the meter from being destroyed or an electrical fire occurs.

2. The aluminum plate stops or does not jump

The watt-hour meter is a precision measuring instrument, which is strictly calibrated before leaving the factory, and its sensitivity, reliability and stability should meet certain standards. When the load current is less than 0.025A, the aluminum plate of the electric meter does not rotate and does not jump, which is a normal range. If it still does not rotate under a large load, it is likely that the aluminum plate is stuck, the aluminum plate has been deformed or the electromagnetic mechanism has failed, and it should be submitted for inspection in time.

3. Self-rotating when no-load

The electric meter will rotate on its own when it is not loaded, that is, all the electrical equipment and lighting fixtures in the house are not in use, and the aluminum plate of the meter is still rotating or crawling slowly. Generally speaking, when the power supply voltage is 80% to 110% of the rated value, the rotation of the aluminum plate of the electric meter will not exceed one circle, which is a normal range. That is, the turntable rotates one circle clockwise. However, if the aluminum plate rotates slightly, it means that there is leakage in the electric meter circuit, and an electrician should be asked to check and deal with it. If there is no leakage, it is the fault of the meter itself, and it should be sent to the power department for maintenance or a new meter in time.

4. "Squeak" sound when running

When the watt-hour meter is running, there is a slight "humming" sound, which is normal. However, if there is an irregular noise in the watch, it is caused by the aging of some accessories inside the watch, the loosening of some components of the electromagnetic field, or the lack of oil in the rotating gear. It should be sent to the power department for verification and replacement of vulnerable parts. Sometimes, when the meter is in serious overload operation, it will also produce irregular noises. Some electrical appliances should be turned off in time to prevent damage to the meter.