Third Party Battery Breaker Requirements
Hazard of electric shock, explosion, or arc flash
All selected battery breakers must be equipped with instantaneous trip functionality with an undervoltage release coil or a shunt trip release coil.
Failure to follow these instructions will result in death or serious injury.
Design Requirements for Battery Breaker
|Battery breaker rated DC voltage > Normal battery voltage||The normal voltage of the battery configuration is defined as the highest nominal occurring battery voltage. This can be equivalent to the float voltage which may be defined as number of battery blocks x number of cells x cell float voltage. Ex: 32 blocks of 6 cells of 2.27 = 435 VDC.|
|Battery breaker rated DC current > Rated discharge battery current||This current is controlled by the UPS and must include maximum discharge current. This will typically be the current at the end of discharge (minimum operation DC voltage or in overload condition or a combination).|
|DC landings||Two DC landings for DC cables are required.|
|AUX switches for monitoring||One AUX switch must be installed in each battery breaker and connected to the UPS. The UPS can monitor up to two battery breakers.|
|Short-circuit breaking capability||The short-circuit breaking capability must be higher than the short-circuit DC current of the (largest) battery configuration.|
|Minimum trip current||The minimum short-circuit current to trip the battery breaker must match the (smallest) battery configuration, to make the breaker trip in case of a short circuit, up to the end of its life time.|