OpenSprinkler Forums Hardware Questions expansion board Re: Re: expansion board

#27878

Ray
Keymaster

One thing you should check is if station 22 and 24 solenoids are shorted. To do so you can measure the resistance between the COM wire and station #22 (same with #24). The typical coil resistance should be around 30 ohm. If it’s too low (like below 15 ohm), you should consider replacing the solenoid. OpenSprinkler doesn’t have shorted solenoid detection feature yet. In the case of shorted solenoid, the fuse is supposed to blow, but if the fuse doesn’t kick in quickly enough, it might damage the triac. Another possibility is damage due to high transient voltage.

If you don’t need #22 and #24, you can use a diagonal cutter to carefully clip away the damaged triac. If you do need #22 and #24, send an email to [email protected] so we can arrange for support.