Pipe Stat wiring question

Anthonyk2010

I got a sunvic stat today and can't understand the wiring.

I have three terminals 1,2,3. 3 is the common(not sure what common is?)

It sayes: Terminal 3 to 2 makes temp rise

Terminal 3 to 1 makes temp fall

I want a motorised valve to close when pipe hit set temp, which way do i wire it?

This is the link to what i'm talking about http://www.sunvic.co.uk/smt.html

DublinDilbert

Their use of language is quite confusing.

They way i would read it is:-
When the temperature is below the set point terminals 3->1 are connected.
When the temperature is above the set point terminals 3->2 are connected.

This would be very easy to test with a multi-meter, as terminals 3->1 should be connected at room temperature.

If you want to close (ie apply power) to a valve, when the temperature reaches the set point, you need to connect to terminals 3 & 2.

Anthonyk2010

DublinDilbert wrote: »

Their use of language is quite confusing.

They way i would read it is:-
When the temperature is below the set point terminals 3->1 are connected.
When the temperature is above the set point terminals 3->2 are connected.

This would be very easy to test with a multi-meter, as terminals 3->1 should be connected at room temperature.

If you want to close (ie apply power) to a valve, when the temperature reaches the set point, you need to connect to terminals 3 & 2.

Goodman Dilbert, agree about the language, they make simple things confusing

Thanks again.

danjo

From the info supplied I would connect 3 to the supply voltage and 2 to the motorized valve. The voltage will then be supplied to the MV, activating the valve, when the temperature rise reaches the level set by the control knob.

Bruthal

danjo wrote: »

From the info supplied I would connect 3 to the supply voltage and 2 to the motorized valve. The voltage will then be supplied to the MV, activating the valve, when the temperature rise reaches the level set by the control knob.

The op says he wants the valve to close when the pipe reaches the set temp. This would indicate terminals 3 and 1 be used, if indeed the motorised valve is required to close(de-energised) when the pipe temp reaches the set point. It can be confusing whats actually required

Maybe its a bypass valve setup or something.

Anthonyk2010

robbie7730 wrote: »

The op says he wants the valve to close when the pipe reaches the set temp. This would indicate terminals 3 and 1 be used, if indeed the motorised valve is required to close(de-energised) when the pipe temp reaches the set point. It can be confusing whats actually required

Maybe its a bypass valve setup or something.

I have a three zone system: up stairs, down stairs and hot water.

I want to set the pipe stat to 60 deg and when water hits 60 the valve closes and turns off burner and when temp drops below 60 valve opens and burner starts again.

Thanks guys

Bruthal

Anthonyk2010 wrote: »

I have a three zone system: up stairs, down stairs and hot water.

I want to set the pipe stat to 60 deg and when water hits 60 the valve closes and turns off burner and when temp drops below 60 valve opens and burner starts again.

Thanks guys

You could get the pipe stat to do that, it would have to be fitted on the return pipe into the boiler. But the boilers own temperature control dial does the same thing already, except does not close any valve. Are there motorised valves on each zone at present?

The reason for seperate zone valves is so one part of house can be heating while others are off. There would not be much point in putting in one valve to close off the entire heating system each time the pipe stat reaches set point.

The normal way its done is the 3 zones have a 3 channel time clock, the time clock has 3 timed outputs to open the 3 zones motorised valves, via room stats and a cylinder stat in the case of the hot water cylinder. Then the motorised valve switch contacts are all wired in parallel to bring on the boiler when any motorised valve is powered on, and turns off the boiler when all 3 valves close due to room stats/cylinder stat reaching set point etc.

Anthonyk2010

robbie7730 wrote: »

You could get the pipe stat to do that, it would have to be fitted on the return pipe into the boiler. But the boilers own temperature control dial does the same thing already, except does not close any valve. Are there motorised valves on each zone at present?

The reason for seperate zone valves is so one part of house can be heating while others are off. There would not be much point in putting in one valve to close off the entire heating system each time the pipe stat reaches set point.

The normal way its done is the 3 zones have a 3 channel time clock, the time clock has 3 timed outputs to open the 3 zones motorised valves, via room stats and a cylinder stat in the case of the hot water cylinder. Then the motorised valve switch contacts are all wired in parallel to bring on the boiler when any motorised valve is powered on, and turns off the boiler when all 3 valves close due to room stats/cylinder stat reaching set point etc.

Ya thats what i have 3 channel timer, 2 room stats and a pipe stat each connected to a motorised valve.

i'm replaceing a pipe stat but its a different make so i'm confused about the wiring.

Bruthal

Anthonyk2010 wrote: »

Ya thats what i have 3 channel timer, 2 room stats and a pipe stat each connected to a motorised valve.

i'm replaceing a pipe stat but its a different make so i'm confused about the wiring.

I see now what you mean, so if you want the pipe stat to close the valve at reaching 60 degrees for example, use terminal 3 for live into stat, and 1 for live to valve from stat.

This would be according to the way dublin dilbert sees it, and it looks that way to me also, but your right, the instructions are very bad.

With the stat set at 60 degrees, test from 3 to 1 with continuity tester and see its closed while stat is just in your hand at room temp,
This would show to use terminals 3 and 1.

If you have no tester then just connect and see it works. Motorised valve will go on as you set temp up to 60 showing its right.

Anthonyk2010

robbie7730 wrote: »

I see now what you mean, so if you want the pipe stat to close the valve at reaching 60 degrees for example, use terminal 3 for live into stat, and 1 for live to valve from stat.

This would be according to the way dublin dilbert sees it, and it looks that way to me also, but your right, the instructions are very bad.

With the stat set at 60 degrees, test from 3 to 1 with continuity tester and see its closed while stat is just in your hand at room temp,
This would show to use terminals 3 and 1.

If you have no tester then just connect and see it works. Motorised valve will go on as you set temp up to 60 showing its right.

Thanks robbie. i'll have a go at in the morning.

is it safe to say common wire is live?

Bruthal

Anthonyk2010 wrote: »

Thanks robbie. i'll have a go at in the morning.

is it safe to say common wire is live?

Yes, but it would not actually matter if the live was into terminal 1 and live out to common, as long as there was nothing being connected to the other terminal, but best practice is live feed to common.

beanie10

Anthonyk2010 wrote: »

I got a sunvic stat today and can't understand the wiring.

I have three terminals 1,2,3. 3 is the common(not sure what common is?)

It sayes: Terminal 3 to 2 makes temp rise

Terminal 3 to 1 makes temp fall

I want a motorised valve to close when pipe hit set temp, which way do i wire it?

This is the link to what i'm talking about http://www.sunvic.co.uk/smt.html

Either way you have to use connection 3 (common). So connect your live in to 3. The next step is to guess between 1 and 2. You will know you have the right one when you turn the stat up to max and the valve is still open, turn stat down to minimum and the valve closes. When you have it operating correctly set the stat to the required temp.