We have been having problems with our FP-1000 loosing communications with the Field Point units it connects to immediately after it initializes. I posted a question previously asking, “What will cause the FP-1000 to fail initialization?” But, in researching this problem we discovered that is most likely is initializing successfully but might be loosing communications with the other Field Point units because the unit next to the FP-1000 is a FP-RLY-422 that is being knocked off line because of ‘Flyback Voltage’ from the circuit breaker relays it is energizing.
How do we determine the correct protection circuit to prevent this from happening? This FP-RLY-422 is controlling 4 circuit breakers. Each is a 208 VAC, 3 Pole breaker that are 50 amp, 32 amp, 25 amp and 10 amp and are electrically held closed. The circuit is designed so that when the FP-RLY-422 is activated it is switched from the NC state to the NO state and energizes the breakers. Within half of a second of this the FP-RLY-422 then returns to the NC position and the FP-1000’s Network and Access LEDs extinguish. Most of the time we can manually open the breakers then perform another initialization and the FP-1000 stays online.
Does this sound like a ‘Flyback Voltage’ problem and would we use a varistor across the load or a diode?
