Zone valve wiring for override

cuda67racer2 · By: **cuda67racer2** On: Tue Jan 08, 2008 8:41 pm

I am in the process of installing a Harman VF3000 in a home that has a two zone system which is controlled by zone valves (Honeywell V8043F). Everything works fine with the exception of the high temp. override. The override is controlled by the Johnson Controls S350, Y350, A350 combo. This setup outputs 110 volts which I ran through a transformer to knock it down to 24 vac. Is there a way I can wire this to an existing zone valve and not have it "smoke" the thermostat that controls the corresponding zone valve when the thermostat is calling for heat at the same time as the override is on? Or is there a zone valve available that allows for two "thermostat" connections?

Thanks

stoker-man · By: **stoker-man** On: Tue Jan 08, 2008 10:03 pm

Are you trying to create a dump zone?

cuda67racer2 · By: **cuda67racer2** On: Tue Jan 08, 2008 10:20 pm

Yes, was trying to use the bigger of the existing zones as the dump zone so it doesnt overheat the house while cooling down.

Highlander · By: **Highlander** On: Tue Jan 08, 2008 10:40 pm

The S350 slave control module is for overheat protection, it has a form C or normally open and closed contact that will transfer 30 degrees higher than what the A350 aquastat is set to.

Not knowing exactly how you wired your system, I would suggest wiring the normally open contact in parallel to the thermostat wires that control your largest zone. I don't know how your circulator pump is controlled, typically the zone valves have a reporting switch which closes when the valve is energized. These switches are used to control the circulator pump either directly or through a relay. When you have an overheat condition, the normally open contact will close, turn on the zone valve for the largest zone and the circulator will then run when that zones reporting switch closes.

Hope this helps.

Flyer5 · By: **Flyer5** On: Tue Jan 08, 2008 10:47 pm

cuda67racer2 wrote:Yes, was trying to use the bigger of the existing zones as the dump zone so it doesnt overheat the house while cooling down.

You can use a double pole relay . You won't even need the transformer . Just get a 110v coil . Something like this http://cgi.ebay.com/AB-ALLEN-BRADLEY-70 ... p1638.m118 You would need a 8 pin base for this one but they are also available . Take your output from the high to activate the coil . Your zone valves can be fed from the secondary side in parallel with your thermostats . Dave

Flyer5 · By: **Flyer5** On: Tue Jan 08, 2008 10:50 pm

or this http://cgi.ebay.com/Potter-Brumfield-12 ... dZViewItem

cuda67racer2 · By: **cuda67racer2** On: Tue Jan 08, 2008 11:06 pm

Thanks for the replies. I was attempting to bring the 110 out of the NO side of the S350, take it to the transformer and then the 24vac out of the transformer to the zone valve. Yes I am using the end switches to activate the circulator pump, so this way as long as a zone valve is open a circulator is on. I may just need to retrace the wires as they come to the zone valve, I may not have them parallel. Either scenario to the zone valve (override or thermostat) works fine independently but when they both attempted to come on at once that is when the thermostat smoked lol.

thanks again

Flyer5 · By: **Flyer5** On: Tue Jan 08, 2008 11:18 pm

cuda67racer2 wrote:Thanks for the replies. I was attempting to bring the 110 out of the NO side of the S350, take it to the transformer and then the 24vac out of the transformer to the zone valve. Yes I am using the end switches to activate the circulator pump, so this way as long as a zone valve is open a circulator is on. I may just need to retrace the wires as they come to the zone valve, I may not have them parallel. Either scenario to the zone valve (override or thermostat) works fine independently but when they both attempted to come on at once that is when the thermostat smoked lol.

thanks again

Thats where the relay comes in . You would still be isolating the thermosts from eachother . You could also get a 24 v relay . Just make sure you get the correct type . The transformer you are using is probably 24vac output . I will try my luck at drawing something that can be posted here . Dave

Highlander · By: **Highlander** On: Tue Jan 08, 2008 11:24 pm

Think of your thermostat as a switch in series with a 24VAC supply and your zone valve. If you backfeed another 24V source into the valve, you have put your "switch" directly across this 24V supply, and have made a short circuit. The other thing to be aware of is that a 24VAC transformer will work in reverse and supply 120V on the primary if you have the secondary on another 24VAC device.

Why do you want to run 110V off the S350 contacts? Are you planning to use this to do something else with this output?

cuda67racer2 · By: **cuda67racer2** On: Tue Jan 08, 2008 11:30 pm

I was mainly running 110 volt out of the S350 due to just utilizing the poor instruction manual from Harman. I will grab the instructions for the Johnson Control and see if I can figure out how to get 24 vac out of it. Is there a way this can be wired to utilize the zone valve for the heating and the override?

Flyer5 · By: **Flyer5** On: Tue Jan 08, 2008 11:50 pm

See if this helps . Sorry it so rough .

beatle78 · By: **beatle78** On: Wed Jan 09, 2008 9:08 am

Hi guys,

I can't really hel;p on the technical side, but if your looking for relays that don't cost a fortune, try these out. They can be used with 220/110/24 VAC as well as some VDC.

http://www.grainger.com/Grainger/items/5LE35

If you search on ebay for RIBU1C you will find some as well.

http://search.ebay.com/search/search.dl ... category0=

Hope this helps,
Jeremy

Highlander · By: **Highlander** On: Wed Jan 09, 2008 11:09 am

Attached is a PDF drawing of a simplified heat dump using the S350 directly wired to the thermostat terminals.
There are many ways to hook something like this up, but this details the very basics of what its supposed to do.

Hope it helps

Flyer5 · By: **Flyer5** On: Wed Jan 09, 2008 4:55 pm

When I read this at 4:30 this morning I thought that you were trying to use both zones for dump .Sorry for the confusion .The reason you let the smoke out of the first thermostat is you were using 2 different transformers . That is creating a Phase to phase short of sorts . The last drawing is what you need . Dave

cuda67racer2 · By: **cuda67racer2** On: Wed Jan 09, 2008 5:24 pm

Dave,
Thanks that makes sense.

Thanks a lot
Bryan

Zone valve wiring for override

Zone valve wiring for override

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Re: Zone valve wiring for override

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Re: Zone valve wiring for override

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Re: Zone valve wiring for override