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



I had a similar issue (the burned triac part) with my shiny new v3 OpenSprinkler. Installed, set it up, created a test program to sequence through the stations as a quick test. First two stations (numbering in order of test program, not zone #s) worked fine, the third station never started. Went back inside to the controller, and was met by an acrid smell and a blank display. Unplugged it, noticed transformer was quite warm.

Opened the case and the culprit was obvious – zone 2 triac (which was the third station in the test program).

All of the solenoids connected to the corresponding COM wire (two boxes, two COM wires) show as open. I’d say I also melted the COM wire, but (a) the fuse on the board seems to be intact (it measured about 1 Ohm), and (b) AC supply is rated at 1A. How is possible to blow the triac without blowing the fuse?

I’ll be running new wires to the valves, but I’m trying to puzzle through what actually happened to be sure I address the root cause. As I understand it, the fuse is on the COM ports, and since the current is sensed relative to DC ground, this effectively makes COM the hot AC line, and the switched port of the triac will tie the individual solenoid wire to board ground through the sense resistor. Is this correct?

I should also note: my purchase of the new Opensprinkler was triggered by the demise of the OsPi we’d been using for the last five or six years. I don’t know really when it died – maybe a week prior to the order. When my wife pointed out that the plants were dying I realized the OsPi was dead and being misled by some troubleshooting errors I ordered the new one (the WiFi performance with the OsPi was abysmal so connection was never a sure thing – while the v3 was alive it was much better!)

When I let the smoke out of the new one, I opened up the case of the defunct OsPi. And found the Zone 2 triac toasted there also. But in this case, the fuse had blown.