OpenSprinkler Forums Hardware Questions OpenSprinkler Fuse Protection Issue, Burned Triac Reply To: Fuse Protection Issue, Burned Triac



Yes, the fuse is connected inline with the COM wire so all solenoids will go through the fuse since all are connected to the COM wire. I can’t explain the burn out. The circuit already has a number of protections in place: each zone has a RC snubber circuit to absorb sudden voltage/current changes, it’s protected by a TVS diode for transient high voltage, and there is an inline fuse on the COM wire. The fuse rating should be higher than 800mA because all triacs can sustain a quite high impulse current (up to several amps) in the event of transient high current. Generally, in the event of shorting, a very high amount of current would flow through the fuse, hopefully burning it out to protect the circuit. So exactly how the traic is burned, I don’t know. Is the expander completely unusable or is it that just the first zone is not?