DIYbanter - View Single Post - Switch For Fan/Heater Unit On 20A Circuit

bud--

On 3/10/2014 2:42 PM, wrote:
On Monday, March 10, 2014 3:05:38 PM UTC-4, bud-- wrote:
On 3/9/2014 3:48 PM, David L. Martel wrote:

Derby,

Your unit draws more than 12 amps, so it needs 20amp wiring, fusing.
That's what needs to go to the switchbox from the main panel.

That is actually if the load is "continuous", which is over 3 hours. It
may be on that long. DD says the manufacturer wants a 20A circuit.

If you load a breaker over 80% and the load is on for over 3 hours the
breaker may trip. That is the only reason I know of for the 80% rule.

The heater draws just under 12 amps. So the wiring to and switch for the
heater should be for 20 amps.

The wiring has to be #12 because the circuit is #12.

The switch can be 15A. I would likely use a spec grade (better quality).

Neither of the switches that you are looking
at can handle 20 amps. Any hardware store will have 20 amp switches in many
styles and colors.

Your fan draws 1/4 of an amp. It will happily work with the humidity
sensor switch. 12-2 is overkill for the fan but you've already got it so use

it.

You need #12 because the circuit is #12.

I agree the humidity switch should be fine.

Dewstop - if the total load is 15A or less and Dewstop is rated 15A you
could use it. But it is expensive. Is it UL listed?

I don't see why the dewstop has to be rated at 15A. The fan draws less
that an amp. It's controlled by that electronic dewstop gizmo. That
would seem to me to be just like putting a ceiling fan controller or
a light dimmer that rated at 700W on any light circuit, be it 15A,
20A, etc. The light dimmer can't handle 15A, yet it's apparently
code compliant, no?

If all you are handling is the fan you don't need 15A, which I said
above for the humidity sensor.

DD also talked about using a "2 function switch" which would presumably
switch the heater.

After looking again, price for the humidity sensor looks OK.

I like timers for bath fans, where you can run it for 5 minutes after
you leave (or whatever). The fan control has a timer too.