[OD Electric]

This is a little complicated to explain. I have a 220v kick heater. The manufacturer instructions and diagram says you have to run a third wire to the snap disk thermostat if you use a remote thermostat. Otherwise you louse the protection of the snap disk thermostat. But if you do that one heating element is hot all the time and the heat thermostat shuts off one leg to the motor which defeats the purpose of the fan delay snap disk. To be safe you have to run 220v to the motor to take advantage of the fan delay and 220v to the remote thermostat to shut down the heater while the 220v fan can run till the heater cools down.
Is It a code violation to run 220v to the motor with one leg going through the fan delay snap disk. Otherwise the fan delay shuts off with the heat thermostat.
It’s a lot, but I hope I gave you enough information to understand my question
Thank you, James ODonohoe

 

[emtnut]

1st. I'd call your poco and see if they can up your voltage to 1920's levels.

 

[backstay]

It would relay help to either list the make and model or include the manufacturer’s wiring diagram.

I assume the t-stat is integral to the heater.

 

[Dennis Alwon]

It would relay help to either list the make and model or include the manufacturer’s wiring diagram.

I assume the t-stat is integral to the heater.

I think the t-stat is remote. I don't quite understand why another wire is needed. My understanding of a snap disk is the method it uses to make and break but how does that differ from a standard t-stat.

Why not use a regular T-stat --DP type

 

[99cents]

You’re saying the fan continues to operate momentarily after the thermostat shuts the heater down? Maybe that’s the reason for the third wire; it provides power to the fan after the two 240V legs are opened (that would mean there’s a neutral at the heater).

 

[backstay]

Most snap discs delay the heater’s fan so you don’t blow cold air.

 

[Forge Boyz]

Most snap discs delay the heater’s fan so you don’t blow cold air.

Most of the ones I've worked on also would run the fan after the element turned off to pull the heat away from it so it doesn't over heat. I know of an installation where a number of heaters are controlled by a thermostat and the elements keep burning out. They need that cool down time.

Sent from my SM-S908U using Tapatalk

 

[99cents]

Most snap discs delay the heater’s fan so you don’t blow cold air.

But how does it get power to continue operating?

 

[samgregger]

To answer your question, technically yes as you are not following the manufactures installation instructions.

 

[micromind]

I don't think it's necessary to open both legs of a 240 heater, a basic standard 2 pole wall-mount thermostat opens only 1 leg for control then when it's turned all the way down there's sort of a click or detent that opens the other leg. This qualifies it for use as both controller and disconnecting means.

In the OPs case, one of the wires is a constant hot. Another is the element controller and the third one is the fan controller. The reason is that once the element is disconnected, the fan needs to keep running to cool the element down.

 

[jamesodonohoe68]

It would relay help to either list the make and model or include the manufacturer’s wiring diagram.

I assume the t-stat is integral to the heater.

Yes, the t- stat was integral. But even that leaves 1 leg hot it's a single pole t-stat. I have 3 diagrams and all are different. I'll try and send pictures. Thanks for your interest

 

[jamesodonohoe68]

I think the t-stat is remote. I don't quite understand why another wire is needed. My understanding of a snap disk is the method it uses to make and break but how does that differ from a standard t-stat.

Why not use a regular T-stat --DP type

Because a 220v t-stat shuts off both legs which shuts down the 220v motor and doesn't cool down the element.

You’re saying the fan continues to operate momentarily after the thermostat shuts the heater down? Maybe that’s the reason for the third wire; it provides power to the fan after the two 240V legs are opened (that would mean there’s a neutral at the heater).

No neutral at the heater. The 3rd wire only sends current to 1 side of the 220v motor.

 

[samgregger]

Because a 220v t-stat shuts off both legs which shuts down the 220v motor and doesn't cool down the element.

No neutral at the heater. The 3rd wire only sends current to 1 side of the 220v motor.

So only switch one leg with the line thermostat.

 

[CAUSA]

I don't think it's necessary to open both legs of a 240 heater, a basic standard 2 pole wall-mount thermostat opens only 1 leg for control then when it's turned all the way down there's sort of a click or detent that opens the other leg. This qualifies it for use as both controller and disconnecting means.

In the OPs case, one of the wires is a constant hot. Another is the element controller and the third one is the fan controller. The reason is that once the element is disconnected, the fan needs to keep running to cool the element down.

X2 on this as well, this is very important for element longevity.

The thermostat should also should be:

Line current design capacity.

Proper heat anticipation function and set up. To prevent temperature over shooting with element cooldown mode.

Should be supplied by the manufacturer but check to see if it can perform the function.

 

[OD Electric]

Most snap discs delay the heater’s fan so you don’t blow cold air.

Not if 1leg of the 220v motor is disconnected by the t-stat.

 

[OD Electric]

Most of the ones I've worked on also would run the fan after the element turned off to pull the heat away from it so it doesn't over heat. I know of an installation where a number of heaters are controlled by a thermostat and the elements keep burning out. They need that cool down time.

Sent from my SM-S908U using Tapatalk

That’s what I found. 1leg to the element is always hot.

 

[OD Electric]

So only switch one leg with the line thermostat.

But than one leg to the element would be hot all the time.
What I did was run 220v up to the t-stat. And 2 12/2 to the heating unit. 1 12/2 from the t-stat to the heating elements and the other 12/2 to one side of the motor and the other to the snap disk thermostat. What do you guys think. Thanks.

 

[OD Electric]

It would relay help to either list the make and model or include the manufacturer’s wiring diagram.

I assume the t-stat is integral to the heater.

It would relay help to either list the make and model or include the manufacturer’s wiring diagram.

I assume the t-stat is integral to the heater.

I have pictures in my cell phone but don’t know how to send it to you.

 

[backstay]

But how does it get power to continue operating?

You don’t, fans in most heaters, furnaces don’t come on until the elements get hot.

 

[Dennis Alwon]

Because a 220v t-stat shuts off both legs which shuts down the 220v motor and doesn't cool down the element.

No neutral at the heater. The 3rd wire only sends current to 1 side of the 220v motor.

I have never heard of cooling off the elements. On a gas furnace the fan runs until the heat in the chamber get low. I have installed many kick space heaters and none were set up to be wired with the fan going with no element. It is a non issue