Heated floor breaker sizing

[hhsting]

I have dwelling unit bathroom where heated floor mat is provided. Its Suntouch Tapat amp drawn at 240V single phase is 1A per 20 sf, watf density is 12W/sq ft.

The bathroom is 7.67ft x 12.17 ft so that 93.31 sq ft.

The total watts is 1116 watts at 240V single phase so the total amps comes to 4.67A.

I was wondering what would be the breaker size in panelboard be 20A or 15A? Plans show 20A with #12 awg cable

 

[tom baker]

Interesting plan review for heated bathroom floor….in my state the inspectors check that.

 

[david luchini]

See 424.3

 

[hhsting]

See 424.3

So then #12 awg with 20A breaker on 4.67A is ok?

 

[augie47]

New word for you: "Google"
Specifications for TapeMat: Floor heating mats are a simple way to heat an indoor space. This instruction manual is provided as a guide to installing TapeMats, including design considerations, installation steps, limitations, precautions, and floor covering guidelines. TapeMat is a complete heating mat consisting of a series heating wire and a power lead for connection to the electric power supply. The heating wire length cannot be cut to fit. Controls: TapeMats must be controlled by a SunStat® floor sensing thermostat. (Listed separately) Voltage: 120 VAC, 240 VAC, 1-phase (see Table 2) Watts: D12 and C12 Series - 12 W/ft2 (41 Btu/h/ft2 ), C15 Series 15 W/ft2 (51 Btu/h/ft2 ) Maximum circuit load: 15 A Maximum circuit overload protection: 20 A breaker GFCI: (Ground Fault Circuit Interrupter) required for each circuit (included in the SunStat control)

 

[hhsting]

New word for you: "Google"
Specifications for TapeMat: Floor heating mats are a simple way to heat an indoor space. This instruction manual is provided as a guide to installing TapeMats, including design considerations, installation steps, limitations, precautions, and floor covering guidelines. TapeMat is a complete heating mat consisting of a series heating wire and a power lead for connection to the electric power supply. The heating wire length cannot be cut to fit. Controls: TapeMats must be controlled by a SunStat floor sensing thermostat. (Listed separately) Voltage: 120 VAC, 240 VAC, 1-phase (see Table 2) Watts: D12 and C12 Series - 12 W/ft2 (41 Btu/h/ft2 ), C15 Series 15 W/ft2 (51 Btu/h/ft2 ) Maximum circuit load: 15 A Maximum circuit overload protection: 20 A breaker GFCI: (Ground Fault Circuit Interrupter) required for each circuit (included in the SunStat control)

Not exactly what i have from engineer. Doesnt say recommended breaker size?

Sent from my iPhone using Tapatalk

 

[tom baker]

The simple answer is to send the engineer an RFI.

 

[tom baker]

So then #12 awg with 20A breaker on 4.67A is ok?

0.00001 amp on 12 AWG with 20 A breaker is ok. Why would it not be ok?

 

[retirede]

0.00001 amp on 12 AWG with 20 A breaker is ok. Why would it not be ok?

I have circuits that often have zero amps on a 20A breaker.

 

[Klockopotomis]

Chances are your drawings say "field verify". So your actual usage is 4.6 ams with an additional continuous load brings you to 6 amps or under. A 15A circuit on 14AWG is plenty

 

[LarryFine]

0.00001 amp on 12 AWG with 20 A breaker is ok. Why would it not be ok?

Only if the manufacturer is depending on the breaker for overload protection, but it should be specified.