I hooked up a new Multiplus Compact 12/2000/80. No battery, just AC IN and AC OUT. When I turn on power it immediately trips the external breaker. I removed the wiring from the Multiplus and directly connected my AC IN/OUT lines together. This works fine so I know the problem isn't in my wiring.
If I check the resistance on the AC IN/OUT between line and common, I see 0.68 ohms on AC IN. This is probably ok since that appears to go to solenoid (among other things). However I see zero ohms between line and common on AC OUT. That doesn't seem right. A visual inspection doesn't reveal any problems.
Any suggestions?