Bathroom heater switch requirements

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mwm1752

Senior Member
Location
Aspen, Colo
Is it considered fix electric heat due to installation or purpose? What if your space heat was electric baseboard & this HVL is considered as a supplemental heat?
 

kwired

Electron manager
Location
NE Nebraska
Is it considered fix electric heat due to installation or purpose? What if your space heat was electric baseboard & this HVL is considered as a supplemental heat?
It is still electric heat and is still fixed in place.

Bring in a portable cord and plug connected heater and now you no longer have fixed electric space heating.
 

Onlyincali

Member
Location
California
iwire mentioned the 15A circuit already, but any continuous load can only be 80% of the circuit's max ampacity, so 16A for a 20A circuit, 24A for a 30A circuit, 32A for a 40A, 40A for a 50A, etc.

Thanks guys, last question...

I just did the install and heater wire of the unit says 14A on it. The manual states the heater is 1400amps and the heater blower is 25 amps. Isn't that much closer to 13amps? If its truly a 14a draw, then it ISN'T safe on the 15a switch....right?

In fact, if a heater is considered a constant load (as stated above) then even a 13a load wouldn't be acceptable on this 15a switch.... Right? Sorry for all the questions. Thanks for the replies
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Thanks guys, last question...

I just did the install and heater wire of the unit says 14A on it. The manual states the heater is 1400amps and the heater blower is 25 amps. Isn't that much closer to 13amps? If its truly a 14a draw, then it ISN'T safe on the 15a switch....right?

In fact, if a heater is considered a constant load (as stated above) then even a 13a load wouldn't be acceptable on this 15a switch.... Right? Sorry for all the questions. Thanks for the replies
I think some of your amps are watts.....
 

Onlyincali

Member
Location
California
Fixed. Good catch.
Thanks guys, last question...I just did the install and heater wire of the unit says 14A on it. The manual states the heater is 1400 watts and the heater blower is 25 watts. Isn't that much closer to 13amps? If its truly a 14a draw, then it ISN'T safe on the 15a switch....right? In fact, if a heater is considered a constant load (as stated above) then even a 13a load wouldn't be acceptable on this 15a switch.... Right? Sorry for all the questions. Thanks for the replies
 

JFletcher

Senior Member
Location
Williamsburg, VA
Thanks guys, last question...

I just did the install and heater wire of the unit says 14A on it. The manual states the heater is 1400W and the heater blower is 25W. Isn't that much closer to 13amps? If its truly a 14a draw, then it ISN'T safe on the 15a switch....right?

In fact, if a heater is considered a constant load (as stated above) then even a 13a load wouldn't be acceptable on this 15a switch.... Right? Sorry for all the questions. Thanks for the replies

Switches are sized for the load. A 15A switch will be fine here. A 600W dimmer can handle 600W of lighting, continuous; it doesnt get 'derated' down to 480W just because the lights may be on all day.

The formula for figuring Watts (W) is Volts (V) times Amperes (I). To figure amps, you divide Watts by Volts.

1400W + 25W = 1425W/120V = 11.875A
 

Onlyincali

Member
Location
California
Switches are sized for the load. A 15A switch will be fine here. A 600W dimmer can handle 600W of lighting, continuous; it doesnt get 'derated' down to 480W just because the lights may be on all day.

The formula for figuring Watts (W) is Volts (V) times Amperes (I). To figure amps, you divide Watts by Volts.

1400W + 25W = 1425W/120V = 11.875A


Thank you!
Just to clarify the 80% rule while we're on this topic....

A switch is rated for constant loads. IE: a 15amp switch can handle 15a continuous loads...always. Right?
A circuit must obey the 80% rule for constant loads. (IE: a circuit can only be loaded to 80% of its rated ability if the load is constant (on for greater than 3 hours))

In other words, a circuit running a 20a breaker, 12g wire, and 3 15a switches (still considered a 20 amp circuit) can run a CONSTANT load of 15a through ONE of those 15a switches and still be legal....right?

Are receptacles rated the same way or do they fall under the 80% rule too? IE: 20a breaker, 12g wire, and two 15a outlets. Still considered a 20a circuit because more than one outlet is being used...right? Can one of those 15a outlets be used for a constant 15a load or does the receptacle itself need to follow the 80% derated rule?

Thanks! I always learn a lot from you guys! (Its sad that I trust face-less people on the internet more than my own subs!)
 

JFletcher

Senior Member
Location
Williamsburg, VA
Thank you!
Just to clarify the 80% rule while we're on this topic....

A switch is rated for constant loads. IE: a 15amp switch can handle 15a continuous loads...always. Right?
A circuit must obey the 80% rule for constant loads. (IE: a circuit can only be loaded to 80% of its rated ability if the load is constant (on for greater than 3 hours))

In other words, a circuit running a 20a breaker, 12g wire, and 3 15a switches (still considered a 20 amp circuit) can run a CONSTANT load of 15a through ONE of those 15a switches and still be legal....right?

Are receptacles rated the same way or do they fall under the 80% rule too? IE: 20a breaker, 12g wire, and two 15a outlets. Still considered a 20a circuit because more than one outlet is being used...right? Can one of those 15a outlets be used for a constant 15a load or does the receptacle itself need to follow the 80% derated rule?

Thanks! I always learn a lot from you guys! (Its sad that I trust face-less people on the internet more than my own subs!)


Receptacles are a bit trickier. See 210.21(B)(1-4) - 2008 NEC reference.
 

JFletcher

Senior Member
Location
Williamsburg, VA
But at same time take a look at the cord cap used on appliances, you almost never see a 20 amp cord cap installed unless it draws more then 15 amps.

I cant remember the last time I saw a 20A cord on a 120V appliance or tool. I have seen 240V 20A plugs, which will fit a 120V 20A receptacle if you cut off the plug ground pin and install the plug upside down (ran into that more than once on PTAC plugs at a hotel I used to work at :happysad:).
 

kwired

Electron manager
Location
NE Nebraska
I cant remember the last time I saw a 20A cord on a 120V appliance or tool. I have seen 240V 20A plugs, which will fit a 120V 20A receptacle if you cut off the plug ground pin and install the plug upside down (ran into that more than once on PTAC plugs at a hotel I used to work at :happysad:).

I can't remember last time either, but can probably produce a big list of things that should have them or even a 30 amp cord cap. If it won't plug into a 5-15 receptacle it won't have as much sale demand so they push things to the limit and still put a 5-15 cord cap on it.
 
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