3 heaters, 3 thermostats, parallel?

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Qwertyjjj

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In the current setup, I have 3 baseboard heaters all on the same circuit (20A 2 pole).
Bedroom 1: 24vac low voltage, 750W, thermostat is connected directly to a transformer on the baseboard.
Bathroom: 240vac high, 500W, thermostat is connected directly to the radiator.
Bedroom 2: 24vac low, 1000W, has a thermostat but it doesn't seem to be connected to the heater...not sure where the connection is.
Junction point in a cupboard that I presume houses the parallel connections.

I want to do the following:
- change both low voltage thermostats to high voltage ones.
- move the heater in Bedroom 1 to the other side of the room.

How can I wire in 2 new thermostats and change this to 240 in a parallel system where each thermostats controls the heater independently.
How is the low voltage stat in bedroom 2 controlling the heater if it's not connected to the heater and on the same circuit as all the others?!
 

DonL

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The T-Stat does not care where the power comes from, for what is is controlling.

The 24Vac transformer that the T-stat is connected to Isolates.

When you hook things together, AC phase can come into play. On 240V even more so.

Your post is a bit confusing. It may be just me.

Be careful playing with electricity.


Good Luck.
 
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Qwertyjjj

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The T-Stat does not care where the power comes from, for what is is controlling.

The 24Vac transformer that the T-stat is connected to Isolates.

When you hook things together, AC phase can come into play. On 240V even more so.

Your post is a bit confusing. It may be just me.

Be careful playing with electricity.


Good Luck.
what part's confusing?
This is a current circuit, I didn't connect it. :)

The 24vac t-stat connected to 1 heater isolates but I can see the connection to the heater.
The 240vac t-stat connects directly to the heater.
However, the 3rd heater has a 24vac t-stat controlling it but it's not connected to the heater so where is it isolating?

Maybe the easiest way would be just to pull 3 new wires for each heater but that's 3 2 pole positions taken up in the 200A panel then.

In theory, I should just be able to remove the 24 low vac and replace it with a 240 if wired into the heater? The thermostat I have has only 2 black wires but as I understand it, they now come with 4?
http://www.aubetech.com/manuel/1/TH104PLUS.pdf
 
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DonL

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what part's confusing?
This is a current circuit, I didn't connect it. :)

The 24vac t-stat connected to 1 heater isolates but I can see the connection to the heater.
The 240vac t-stat connects directly to the heater.
However, the 3rd heater has a 24vac t-stat controlling it but it's not connected to the heater so where is it isolating?

Maybe the easiest way would be just to pull 3 new wires for each heater but that's 3 2 pole positions taken up in the 200A panel then.

In theory, I should just be able to remove the 24 low vac and replace it with a 240 if wired into the heater? The thermostat I have has only 2 black wires but as I understand it, they now come with 4?
http://www.aubetech.com/manuel/1/TH104PLUS.pdf


Looks like French to me. A pro that knows French may be by shortly.

Good Luck.
 

Jadnashua

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There are line voltage thermostats and low-voltage thermostats. A low voltage thermostat is probably easier to install than a line voltage one, especially if you want your sensing circuit to be remoted somewhat. All the low-voltage one does is control a contactor or relay (maybe a solid-state one) to turn power on and off. The line-voltage ones use a 240vac coil on the relay or contactor verses a 24vac coil on the low-voltage one. While it would work, it is not safe to just break one power lead with the 240vac circuit to the heaters...you need a double-pole relay or contactor to do that. If you now understand this, it should not be a really hard task. If you don't, you probably should not be doing it yourself, at least not without some more research.
 

Qwertyjjj

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Ignore the French, just look at the diagrams :)
It seems like they suggest to only break one leg of the power in the 2 wire setup in the manufacturer's instructions? This is also how the electrician connected it.
Personally I find the 240 thermostats easier than the 24vac. Why go through a relay (plus the cost of relay and 24vac stats are more expensive) when you can just go direct to the heater?
 
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Qwertyjjj

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Does this plan look ok?
(all using 12/2 wire 20A 2 pole breaker, 240 t-stats and 240 baseboards)? It is wired with 2 wire t-stats using the existing power supply cables to the heaters as the junction point.
If the newer t-stats have 4 then I'd have to have double the wire I think to go to the thermostat first and then back to the baseboard to break both legs of the power.
 
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hj

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A 240 v. system MUST have both feed wires going THROUGH the thermostat so that it completely disconnects the heater when the thermostat is off, or satisfied.Your wiring diagram looks like a spider web.
 

Qwertyjjj

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A 240 v. system MUST have both feed wires going THROUGH the thermostat so that it completely disconnects the heater when the thermostat is off, or satisfied.Your wiring diagram looks like a spider web.
not if it's a single pole thermostat...it's not possible to do it
 

Jadnashua

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A single pole line voltage thermostat would work on a 120vac heater, but should not be used on a 240vac unit for safety reasons. While opening only one leg will stop the heater from working (or should!), you'll still have 120vac to ground constantly in the heater that is supposedly off; not a good situation.
 
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