Cooling Celem Capacitors
- The dielectric in most Celem’s capacitors is polypropylene, which can be safely heated up to 90°C during operation without any degradation. Under full power when this temperature is achieved at the hottest point of the capacitor’s core, the external temperature of the capacitor’s surface is 45 - 50°C.
- We recommend to measure the capacitor’s copper surface and to make sure that it is below 40 degrees C. For operation below full power, the external temperature of the capacitor could be more than 40 degrees C. Please check here.
- Better cooling can be achieved either by using colder water, or by increasing the flow.
- For safety cooling margin the losses of a mounted Celem capacitor can be estimated to be of the order of 1/700. Therefore one should expect that 500kVAr capacitor at full power will generate 715W of heat.
- Water flow of 1 liter/minute when dissipating 1kW will be heated by 14 degrees C. (calculated by specific heat of water) This ratio enables to calculate the desired water flow, once power losses and water inlet temperature are given.
- Maximum inlet water pressure in Celem water cooled capacitors is 5 Bar.
- Both sides of a Conduction Cooled capacitor must be connected to a water cooled bus bar.
- When brazing the water tube to the bus-bar, it is recommended that the tube will be as close to the capacitor as possible.