The description of the OpenEVSE says that it can control two relays, but in most images an videos I see that the power to the relay block is just one pair of cables (12V and 0V), so there is not actually a relay test taking place.
Also if there were two relay outputs, how do you perform a relay test? Even if you turn only one relay at a time, any one J1772 plug terminal pin would get live 240V with respect to Ground, not really safe.
AM I missing something?
OpenEVSE can power either 2 SPST or 1 DPST relays. DPST is more popular. The relay is cycled only if the Auto detect service level is set for countries that use split phase.
0 hots detected NO GROUND Error
1 hot setected Level 1
2 hots detected Level 2
Stuck Relay test runs continuously whenever the relay is open. Ground test runs continuously whenever the relay is closed.
The test feature for ground does intensionally leak a very small current to ground. Turn one relay on and read AC detect chips then turn the other on and read the chps again.
See the flow chart attached