"you only need to energize the solenoid"..
I had been wondering how I was going to keep the Sanyo in heating mode.
The 'Indoor unit' will be replaced by a refrigerant-to-water heat exchanger.
The 4-Way Valve (connectors RV0 & RV1) will need to be 'Energized'
or maybe left off?
Notice that RV1 is the second Relay in the relay stack.
(Note: T-Run/Test connector is in the center bottom of PCB).
I'm betting the default power-up is Cooling mode. If that's true, I'll have to make a mod.
If RV1 is hot after power up, I'll just unplug the connector.
Or, if RV1 is off after power up, I'll need to jumper across the relay. (RV1 to AC2).
(In this case, I would use an SSR as the jumper. So as to allow for DIY Defrost mode in winter).
OR,
If I'm wrong and the default power-up is heating mode. I'm Golden.
One goal is to hack/configure the unit to power-up in the heating mode, as it's default.
Then use the 'T-Run/Test' connector to start-up heating mode (remotely).
If that hack-config is possible, then I could leave the unit powered on,
to keep the crank-case oil nice and warm..
It the hack fails to work, and the T-Run has to be shorted before power-up,
then AC power would need to be used to control the Off-On function.
That would mean running a hot AC power line to the crank-case heating element.
It's starting to look like this project might be possible..
~~~
Recently, one poster had a bad install that was hard to figure out..
The mini-split would only run in Cooling mode. No matter that he had selected heating.?.
His Electrician had wired the 230v mini-split with 115v !! And it cooled just fine..
So, maybe the AC2 (AC power source for the relays) was stone cold.?.
And it needed to be energized ??
Makes me wonder if his crank-case heater was off too..?.
