Yueqing Chirx Electron Co.,Ltd

Our company is one of core enterprise in Wenzhou and one of best Chinese capacitor manufacture.

Home > News > Content
CBB60 Motor Run Capacitor Test And Operation And Maintenance
- May 24, 2017 -

The CBB60 Motor Run Capacitor  is a static reactive power compensation device. Its main role is to provide reactive power to the power system to improve the power factor. The use of local reactive power compensation, can reduce the transmission line transmission current, play a line to reduce energy loss and pressure drop, improve power quality and improve equipment utilization of the important role.

First, the protection of CBB60 Motor Run Capacitor  

1. Proper protection of the capacitor bank

Such as the use of balanced or differential relay protection or the use of transient over-current relay protection, for 3.15kV and above capacitors, each capacitor must be installed on a separate fuse, the rated current fuse should be the characteristics of the fuse And the inrush current to select, usually 1.5 times the rated current of the capacitor is appropriate to prevent the capacitor tank explosion.

2. When necessary, several protective measures

① If the voltage rise is frequent and long time, take measures to make the voltage rise of not more than 1.1 times the rated voltage.

② with the appropriate current automatic switch protection, so that the current rise of not more than 1.3 times the rated current.

③ If the capacitor with the overhead line connection, the appropriate arrester can be used for atmospheric over-voltage protection.

④ In the high-voltage network, short-circuit current exceeds 20A, and short-circuit current protection device or fuse can not reliably protect the ground short circuit, you should use single-phase short circuit protection device.

3. Correctly select the protection mode of the capacitor bank

To ensure the safe and reliable operation of the key to the capacitor, no matter what kind of protection, should meet the following requirements:

① protection device should have sufficient sensitivity, regardless of the capacitor group within a single capacitor failure, or part of the components damaged, the protection device can be reliable action.

② It is possible to selectively remove the faulty capacitor or to check the damaged capacitor after all the power of the capacitor bank has been disconnected.

③ protection device can not malfunction when the capacitor is stopped and the power system is grounded or other fault.

④ protection device should be easy to install, adjust, test and operation and maintenance.

⑤ consumption of electricity to be less, operating costs to be low.

4. Capacitor does not allow automatic reclosing device

The opposite should be installed without pressure release automatic trip device. Mainly because the capacitor discharge takes some time, when the capacitor group switch trip, if immediately reclosing, the capacitor is too late to discharge.

In the capacitor may be remnant with the reclosing voltage polarity of the opposite charge, which will close the moment to produce a large impact current, resulting in expansion of the capacitor shell, fuel injection or even explosion.

Second, the CBB60 Motor Run Capacitor  connected and disconnected

1. CBB60 Motor Run Capacitor  group

Check the discharge network before using the megger.

2. When connecting and disconnecting the capacitor bank, the following points must be considered

① When the voltage on the busbar (bus) exceeds 1.1 times the maximum allowable voltage, it is forbidden to connect the capacitor bank to the grid.

② in the capacitor group from the grid after the break 1min shall not re-access, but the automatic repeat access except.

③ When the capacitor bank is turned on and off, use a circuit breaker that can not generate dangerous overvoltages, and the rated current of the circuit breaker should not be less than 1.3 times the rated current of the capacitor bank.

Third, the discharge of CBB60 Motor Run Capacitor  

1. capacitor discharge

Discharge should be performed automatically each time it is disconnected from the grid. The terminal voltage is rapidly reduced, regardless of the rated voltage of the capacitor is the number of capacitors in the disconnect from the grid after 30s, the terminal voltage should not exceed 65V.

2. How to protect the capacitor bank

In order to protect the capacitor bank, the automatic discharge device should be mounted on the load side of the capacitor circuit breaker and is often connected directly to the capacitor (the circuit breaker, disconnector and fuse are not allowed in the middle). A capacitor bank with a non-dedicated discharge device.

For example, for a voltage transformer for a high-voltage capacitor, an incandescent bulb for a low-voltage capacitor and a capacitor group directly connected to the motor may not be equipped with a discharge device. When using the lamp, in order to extend the lamp life, should be appropriate to increase the number of light bulb series.

3. The capacitor discharges separately

Even if the capacitor has been automatically discharged before the conductive part of the capacitor which has been disconnected from the grid, it must be discharged with an insulated grounded metal rod and shorted to the outlet of the capacitor.

Fourth, the operation of the capacitor maintenance and maintenance

1. Capacitor operator requirements

① should be on duty, should do a good job of equipment operation records.

② on the operation of the appearance of the capacitor group inspection inspection should be carried out according to the regulations every day, such as the discovery of shell expansion should stop using, so as to avoid failure.

2. How the capacitor is maintained

① Check the capacitor group per phase load can be carried out with ammeter.

② When the capacitor group is put into the ambient temperature can not be lower than -40 ℃, the operating environment temperature of 1 hour, the average does not exceed +40 ℃, 2 hours on average shall not exceed +30 ℃, and an average of no more than +20 ℃. If it is over, use manual cooling (install fan) or disconnect the capacitor bank from the grid.

③ The temperature check of the installation site and the inspection of the hottest temperature on the capacitor housing can be carried out by means of a mercury thermometer and the temperature record (especially in summer).

④ The working voltage and current of the capacitor shall not exceed 1.1 times the rated voltage and 1.3 times the rated current when used.

⑤ connected to the capacitor, will cause the grid voltage increases, especially when the load is light, in this case, should be part of the capacitor or all the capacitors from the power grid disconnected.