Quote:
Originally Posted by Mikesolar
Also, how come you use SSR instead of regular relays?
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I prefer SSR's for switching loads for a several reasons:
1. They have zero cross detect so no big electrical spikes or need for snubber circuits
2. They don't need a transistor driver circuit to switch them on/off
3. No contact wear due to arcing
4. Silent operation (not important in noisy environments)
They are also as cheap or cheaper than a conventional mechanical relay.
For low current switching I do use conventional relay modules. I know the commonly available relay modules are rated at 10A but I'm not sure I'd be happy putting 10A through one, just personal caution.
Some questions:
1. What do you need to provide (voltage and power wise) to the W, Y and O/B inputs? Is it mains power?
2. Why is there a separate connection for the rev valve if there are separate wires for heat/cool? Do you have a schematic of the machine?
3. It sounds like the 'regular t-stat' is already in use so will the room temperature come from a separate stat or from an NTC (this is for the failure detect you require)?
4. Does the hp look after its own power failure/restart and defrost cycles?