3 way valve

[Theo]

I have some instructions for a (Japanese) heating controller which has an output for a hot water/central heating 3 way valve. The terminals are labelled:

1ph 230V, 1A 1=Neutral, 2=Phase, 3=Signal

That's all it says. There is a diagram of 3 wires going to a T-shaped valve (3 triangles pointing towards the midpoint) with a motor on top, which leaves me none the wiser. It doesn't define what 'signal' does, nor does it indicate which position it should go, nor what happens if you apply mains to 'phase' or 'signal'

I think it's intended so you get one or other of DHW and heating, not together. (ie what we would call W-plan)

Is this kind of labelling a standard in any way, such that 'phase' and 'signal' are well defined?

I watched this video:

which suggests you apply current to both inputs of a 3 port valve to switch from DHW to heating.

Does this accord with the wiring description above? Or is 'phase' a permanent live and 'signal' a switched live? Or maybe 'signal' is an output from the valve to indicate when the valve has changed over?

I should probe it to see what it does, but I don't want to fry anything by wiring it up wrong.

Anyone recognise this? There's various things it could be, but a bit lacking on anything to go on. It's probably the usual way they do things in Japan, whatever that might be...

Thanks Theo

[Steve Walker]

Phase is another word for Live and Signal will switch it over.

I don't know how it works. It may be as you have stated or it could be that it sits to one position unpowered, another if power is applied and the third if Signal is applied as well.

[ARW]

Would be my guess

[Smolley]

Try it out on the bench.

[John Rumm]

Yup a diversion valve will stay in one position when unpowered, and move to the other when powered. Hence you would only need a switched live feed to move it. So probably "signal" in this case.

You could check with a multimeter - but I would guess that neutral and phase is the permanent live that powers the controller. The signal is the "call for heat" output. See if mains shows up on signal when the controller is demanding heat.

On the bench with nothing connected to signal other than the SMM you should be fine.

Yup if you have a traditional mid position valve, then it will spring return to the DHW position. It can be used as a changeover valve if required:

In system:

Details of circuit:

So my guess would be "signal" connected to white and grey wires on a normal mid position valve would give you all flow to the CH output, and no power at all will do all flow to DHW.

[Roger Mills]

Dunno - I'm mistificated!

In British systems, a diverter valve (W-Plan) has 2 wires plus earth and a mid-position valve (Y-Plan) has 4 wires plus earth.

Yours valve seems to be neither fish now fowl!

[Theo]

Hmm, that was a possibility I hadn't considered - 'signal' means 'changeover' rather than 'port A'. So every pulse on 'signal' causes it to toggle?

Will do, when I get a chance. (These pins are outputs, mains comes in to the controller via another port)

I spent some quality time on Yahoo auctions and Google Translate, best I could come up with was things like this:

an image so can't be translated, the words underneath say '(Indicates the switching status when CS is energized.)'

5 wires, of which two seem to go to RL and GL (red light and green light?). Appears C is neutral, mains changes over between pins S and O.

S looks like a normally-live and O is a normally-open.

When S is live, switch LS1 is closed, red light is on.

When O becomes live, motor powered through switch LS2. Presumably at some point the switches change over and the green light comes on. That also cuts power to the motor. I'd guess you then apply current to S again to flip it the other way.

That would be quite nice if so, because it would then directly convert to S-plan - each of S and O to neutral can drive a 2-port valve.

Alternatively that valve still works if S is permanently live, which wouldn't be right for S-plan. I shall have to test it and see.

Thanks for the links - I keep forgetting to check the wiki for this kind of stuff, it's very handy!

Theo

[John Rumm]

For most common valves, they require power to be maintained for the duration of the call for heat. So if you want CH, then the thing must be driven all the time you want CH.

(there are some Motor on/Motor off values that don't have a spring return, and when left unpowered will stay put - but these are far less common IME)

So "Signal" likely to be a switched live - i.e. a state driven thing and not an event.

If you point a phone at the page when displayed on screen, translate or "lens" will do a real time translation of the text.

You can also upload a file to google drive, then open in docs, and select translate from the tools menu. That will let you save a new copy in a language of your choice...

Alas it does not work well for heavily formatted pages like your PDF, but does get some of it:

Perhaps we should take its from the question, what are you attempting to achieve?

(If the answer is, have your controller drive a bog standard mid position valve or a diversion valve, then I expect it is pretty straight forward)

[Theo]

That's what I would have expected. And 'phase' probably means permanent live.

Hmm, interesting but none the wiser!

This is an unused output on an ASHP. I'm wondering if it's possible to drive an S-plan setup. If 'signal' is a simple level output (live for position X, not live for position Y) it should be feasible to drive some

2-port valves via a relay (NO for X, NC for Y). If we have to provide feedback (ie an output that closes to confirm the 3-way valve has changed over, eg before the pump is started) then that gets more complicated. I suppose you could series the switches in the 2-port valves, or something like that.

Theo

[John Rumm]

Yup, some measurements on the controller are needed to work out what you are actually dealing with...

Or include a bypass valve to make sure there is always a free path if all the other valves are occluded.