Prevent electric shock measures of the detection capacitor

Some workers believe that the capacitor is equipped with a discharge device, and no manual discharge is required for maintenance. In fact, this idea is wrong. Since the charge stored in the capacitor is discharged through the discharge device, there is still the possibility of residual charge (especially inside the capacitor), so no matter which type of discharge device is installed, it must be repaired after manual discharge.

The method of manual discharge is: first fix the grounding end of the grounding wire, and then discharge the capacitor multiple times with the grounding rod until there is no discharge spark and discharge sound. If the internal fault of the capacitor is repaired, although there may be residual charge in the fault part through manual discharge, insulating gloves should be worn to short-circuit the faulty capacitors before they can be repaired.

The patrol inspection of the capacitor bank shall perform daily inspections of the capacitor bank in operation and special inspections.

1. Daily inspection inspection project of capacitor bank:

(1) Check whether the capacitor is running under rated voltage and rated current, and the value of the three-phase ammeter should be balanced;

(2) The casing is completely clean, free from cracks or discharges;

(3) The terminals of each connecting line should be tight and not hot;

(4) The capacitor casing has no deformation, expansion and oil leakage;

(5) There is no abnormal sound inside the capacitor;

(6) There is no flashover outside the capacitor;

(7) The casing is grounded intact;

(8) The capacitor room should be well ventilated, and the operating environment temperature should not exceed 45 °C;

(9) The protective devices of the capacitors are all put into operation;

(10) Check the capacitor circuit breaker, transformer, reactor, discharge coil, etc. should be no abnormality.

2. When there are the following situations, the number of inspections should be increased:

(1) When the system voltage is too high;

(2) When the capacitor bank is put into operation after being overhauled, modified or long-term deactivated;

(3) When running with defects and abnormal operation of the equipment;

(4) When there is a bad weather or a suspicious phenomenon in operation;

(5) When there is an important power supply task.

3. When the capacitor group is short-circuited and the fuse is blown, special patrol inspection should be carried out immediately. In addition to the above items, the inspection items should be tested when necessary. The power supply cannot be re-closed until the faulty capacitor or the breaker trip fuse is detected.