The PGA-1100 Diode Logic module is an optional accessory for the Littelfuse Arc Flash Relays.
It is used in installations with more than one breaker and more than one Arc Flash Relay. The purpose of the unit is to separate the trip paths, so the breakers can be tripped independently from each other. Typical applications are switchboards with two incoming feeders and one tie breaker or switchboards with several protected zones and tripping of a common upstream circuit breaker.
 
The unit has three input diodes to handle the outputs of three Arc Flash relays and three output diodes to handle the trip coils of three circuit breakers. If more than three relays/circuit breakers are needed, more units can be added by connecting terminal 8 of one box to terminal 4 of the next one, thus increasing the number of inputs and outputs with multiples of three.
 
For more application information please refer to the arc flash relay manuals.