Built-in electrical protection devices

 

 
 
 

HRS fuses

Protection using HRC fuses integrated in the capacitor bank ideal (technically and economically) for capacitor banks with the following characteristics :

-Low power (<1000 kVar)
-Those equipement with three-phases connection capacitors
-Supply voltage less than 12 kV

The rating of the HRC fuses will be selected to have a value between 1.7 and 2.2 times the nominal current of the capacitor bank.
HRC fuse blow-outs are genrally caused by a short circuit inside the capacitor.

 

Unbalance or differential protectione

Protection sensitive, capable of detecting and reacting to a partial fault in a capacitor.
This protection generally applies to capacitor banks with the following characteristics :

-Medium or high power (>1000 kVar)
-Those with single phase connections capacitors
-Supply voltzgr greater than 12 kV

It consists of a current transformer connected between two electrically balanced points, combined with a current relay. When there is a fault in a capacitor there is an balance and therefor a current circulating in the current transformer, which will cause, by means of the relay, the banks'oeprating device (circuit breaker, swich, contactor,etc.) to open.