Selecting Transformers for Electric Baseboard Heat

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Molo

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Hello All,
We have electric baseboard heat in multiple rooms with multiple thermostats. It hasn't been used in years and we want to get it running. We want to replace the transformers that are mounted on the sub-panel. The sub-panel is dedicated to the heat and has 7 transformers mounted on the outside. The transformers have the low-voltage thermostat wire coming into them and heavier wires going into the panel. I want to be sure we are replacing the transformers with the correct equipment, and would appreciate some direction on how to select the correct transformers.

Thanks in Advance,
Bill
 

DonL

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No model number or nothing ?

Any should do. lol

Why are you replacing them ?


Good Luck.
 

Molo

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No model number or nothing ?

Any should do. lol

Why are you replacing them ?


Good Luck.

There are model numbers, but I'm sot sure the existing are correct. I'm trying to determine what are the correct transformers to use for this application
 

Jadnashua

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Are they 24vac output thermostat control transformers? Sounds like it. There should be a VA rating stamped somewhere on the frame. That is essentially a rating that tells you how much power it can provide. You need one that can provide at least that much so that it doesn't overheat when closing the power contactor that breaks the power to the units. A bigger one will work, but will have more standby losses. A smaller one may just end up burning up, or failing to activate the contactor.
 

Molo

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Are they 24vac output thermostat control transformers? Sounds like it. There should be a VA rating stamped somewhere on the frame. That is essentially a rating that tells you how much power it can provide. You need one that can provide at least that much so that it doesn't overheat when closing the power contactor that breaks the power to the units. A bigger one will work, but will have more standby losses. A smaller one may just end up burning up, or failing to activate the contactor.

If this was a brand new project, with no existing units in place, how would I select the appropriate relay? I don't know if the existing ones are correct, so I don't want to use them as a reference.
Thanks
 

DonL

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If this was a brand new project, with no existing units in place, how would I select the appropriate relay? I don't know if the existing ones are correct, so I don't want to use them as a reference.
Thanks


If you do not know what you are doing, You should not be Playing with Electricity.

You need PPE and the works, to be safe.


Kick back and drink a Red Hook.
 

Molo

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If you do not know what you are doing, You should not be Playing with Electricity.

You need PPE and the works, to be safe.


Kick back and drink a Red Hook.

I am not going to do the work myself. Just doing some homework on the proper equipment.
And oh yes, how do I change the picture next to my posts?
 

Jadnashua

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You would need to know the actual load of the heaters. The relay contacts will be rated for up to a certain number of amps and max voltage levels...then, you need to know what voltage the coil of the relay is designed for (typically it's either low-voltage - 24vac nominal, or it could be 120-vac or 240vac). WHen you read the spec on the relay, it will also usually have different ratings for the type of circuit (say a motor verses a resistive load - your heaters are likely a resistive load unless they also contain a motor).
 

Molo

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You would need to know the actual load of the heaters. The relay contacts will be rated for up to a certain number of amps and max voltage levels...then, you need to know what voltage the coil of the relay is designed for (typically it's either low-voltage - 24vac nominal, or it could be 120-vac or 240vac). WHen you read the spec on the relay, it will also usually have different ratings for the type of circuit (say a motor verses a resistive load - your heaters are likely a resistive load unless they also contain a motor).

Thanks Jad,
There may be only a couple of electricians in my area who could figure this out. Most would just replace what is there, and this is not what I want to do. I wonder if the heater manufacturer can recommend a relay.... I'll post back with their response.
 
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