First, installation

1. It is strictly prohibited to carry capacitors with casing. When the capacitor is hoisted, attention should be paid to avoid collision and friction, and care should be taken to avoid damage to the casing.

2, capacitors can be installed on the frame, for good ventilation, each layer of capacitor spacing should not be less than 50mm. The row spacing should not be less than 150mm. Capacitor bottom distance from the ground indoor products should not be less than 200mm, outdoor products should not be less than 300mm, the device top clear distance should not be less than 1000mm.

3. The electrical connection of the capacitor must use a soft connection, and the connection should be carried out by clamping two wrenches (preferably using torque wrenches) up and down, and the tightening torque should not be greater than 30N.m.

4, the fuse selection and capacitor matching, reliable quality of the fuse, in strict accordance with the manufacturer's way of installation.

5, when the capacitor is installed on the insulation bracket, the housing potential must be fixed.

6. When the capacitor shell is grounded, the grounding part should be kept in good contact.

Ii. Protection

1, capacitor banks should take appropriate protection measures, such as the use of unbalanced differential voltage, neutral line imbalance current, bridge difference current, and open triangle voltage protection, the use of short delay overcurrent, bus interphase short-circuit quick break and overvoltage, voltage loss relay protection.

(2) When the capacitor is installed on each capacitor specifically to protect the fuse of the capacitor as required, the fuse should comply with the relevant standards, the fuse should be able to withstand the surge current when the capacitor is put In, and the peak surge current should not exceed 100In (In is the rated current of the capacitor). The rated current of the selected fuse is generally 1.5 times to 1.6 times the rated current of the protected capacitor, and the fuse is installed in strict accordance with the manufacturer's regulations to prevent the explosion of the capacitor fuel tank.

3, other protection: In order to limit atmospheric overvoltage and operating overvoltage, zinc oxide arrester protection can be used.

Three, cut

1, when the voltage on the bus exceeds the specified. When the allowable value is large, do not connect the capacitor bank to the network.

2. The capacitor bank shall not be re-connected within 10min after it is disconnected from the network.

3, capacitor use circuit breaker must use circuit breaker products, the rated current of high-voltage circuit breaker should be not less than 1.5 times the rated current of the capacitor bank, the selection of high-voltage circuit breaker without heavy breakdown, for the high-voltage circuit breaker required to remove the short-circuit fault, the rated breaking current should be greater than the short-circuit current of the device installation site system. The aging test report of circuit breaker interrupter chamber is also available. The aging test is beneficial to remove the gas, oxide and impurities on the electrode surface, improve the voltage level of vacuum interrupter chamber, and avoid the re-breakdown of the break.

4. When the voltage on the capacitor terminal rises more under light load, part or all of the capacitor should be cut out.

Iv. Discharge

1, each time the capacitor composition is disconnected from the network, its discharge should be automatic.

2, in order to protect the capacitor bank, the automatic discharge device should be directly connected with the capacitor (no circuit breaker in the middle, knife switch, etc.). Capacitor banks with non-dedicated discharge devices (e.g., V-wired voltage transformers for high-voltage capacitor banks) and capacitor banks directly connected to the motor may no longer be equipped with discharge devices.

3. Before contacting the conductive part of the capacitor disconnected from the network, even if the capacitor has automatically discharged, the outlet end of the capacitor must be short-circuited and connected with the ground wire for separate discharge.

5. Maintenance

1. Daily maintenance:

A. The capacitor room should have staff or equipment on duty to record the operation in detail.

B, it is recommended to check the appearance of the capacitor every day, such as the capacitor should be free of leaking oil, joint heating and shell swelling.

C, the temperature of the capacitor installation site should be monitored and recorded.

D. The surface of the capacitor bushing should not be covered with dust to prevent pollution flashover accidents.

2, regular inspection:

Capacitors can be inspected regularly once a year. Capacitors operating under special conditions can appropriately shorten the inspection period according to the specific circumstances. The specific contents of the inspection are as follows:

A. Measure the unit capacitance and compare with the previous record. If there are significant changes, timely replacement with the same specifications of the product. Check whether the capacitor is leaking oil or has been polluted. Clean up any dirt.

B, often check whether the contact of all electrical connection points is good, if there is an accident should be handled in time to avoid accidents. All electrical connections in the capacitor bank must be tight and reliable, and any contact or poor connection may cause high frequency oscillation caused by arcing, causing the capacitor to overheat and overvoltage.

C, check the setting value and operation of the relay protection.

(3) Once the capacitor fails, it should be recorded immediately (voltage, current, load and capacitor capacitance, number, etc.), and it should not be put into operation again before the cause is identified and the correct treatment is made.

4, strengthen the inspection of the fuse arc extinguishing tube. Timely replacement of corroded and relaxed fuses to avoid the deterioration of fuse breaking performance and reignition, heavy breakdown caused by the expansion of the accident. After the one - or two-phase fuse of the three-phase line circuit is blown, all the three-phase fuse should be replaced.