I have a dedicated 20 amp breaker that feeds a dedicated circuit for all the GFCI outlets in the bathroom (5). I also have a SunTouch floor thermostat attached to a warming pad under the floor that says it can go on a 15 amp or 20 amp circuit depending on the size of the floor. I was planning to attach the thermostat in line (series) with this 20 amp circuit. Does anyone foresee any issues?
Electrical – add Suntouch floor thermostat to 20 amp breaker circuit with in-line GFCI outlets
electricalthermostatwiring
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This Blender which is used in the "Will it Blend" commercials requires a dedicated 20amp circuit. I have a smaller model but it still pulls 10amps! Now most people don't have these, but there certainly are all sorts of mixers, blenders, bread makers, etc. that might require this type of amperage.
I believe that you are required by NEC (in new builds anyways) to have dedicated 20amp outlets in the kitchen. I think that it's not so much that a single device will pull 20amps, but two devices plugged into a single outlet might.
From your diagram it looks like the grounded (neutral) conductor connected to the light (that trips the GFCI), does not come from the GFCI device. It looks like the grounded (neutral) wire is coming from the feeder to the circuit, instead.
Because of this, you'll have current flow through the GFCI device on the ungrounded (hot) conductor that does not flow back through it on the grounded (neutral) conductor. The GFCI sees this as a ground-fault, since the current on the ungrounded (hot) and grounded (neutral) conductors are different.
To remedy the situation, you can either not provide GFCI protection to the light, or connect the grounded (neutral) conductor from the light to the LOAD side grounded terminal of the GFCI device.
Essentially, this is what it looks like you have now.
Notice that the grounded (neutral) conductor bypasses the GFCI device.
No GFCI Protection
To fix this you could not GFCI protect the light, which would involve making a wiring change in the switch box. You'll have to move the wire feeding the switch from the LOAD side of the GFCI, to the ungrounded (hot) conductor feeding the box. The final circuit would look something like this.
In this situation, your original diagram would look like this.
GFCI Protection
The other option is to connect the grounded (neutral) conductor from the light to the GFCI, which would require running an additional conductor between the light box and the switch box. You'd then use the extra conductor to run from the grounded (neutral) LOAD terminal of the GFCI, to the grounded (neutral) terminal on the light.
If you go this route, your original diagram will look like this.
NOTES:
- This answer is based on the assumption that your diagram is correct.
- If local codes require the light to be GFCI protected, you'll have to do what is necessary to provide GFCI protection to the light.
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Best Answer
The Suntouch has a built-in GFI. Don't connect load sides of GFI's to other GFI's. They'll burn each other out.
If you're running a 120v mat, you're going to pull alot of amperage. Best to see if you can try a temporary hookup to the circuit in question, then try a hair dryer (and/or whatever other appliances you'd run on that circuit) on that circuit at the same time the floor heat is on, to see if it'll hold. You'll probably be pulling somewhere near 11-15 amps (that's a guess, you need to check) with that size mat, so you're getting close.