Perhaps *you* won't ever turn on all the heaters at once, but what about the
next homeowner? Resistance heating is definitely subject to the 80% rule,
which means that the circuit is limited to 15A * 240V * 80% = 2880 watts. Four
750W heaters is 3000 watts. Not much over the limit, but still over. With all
four in use, the breaker won't trip, but it is possible to overheat the
On Oct 25, 11:27 am, firstname.lastname@example.org (Doug Miller) wrote:
I hear your concerns. While I plan to own this place for many years,
I am a big proponent of doing things right and not handing my problems
off to someone else. I certainly could not handle it if any harm came
to someone downstream from my actions.
I will add a new circuit and string a new 14 gauge wire for the new
Again my thanks to the group knowledge base.
On Oct 25, 5:09 am, email@example.com (Doug Miller) wrote:
If I can add an additional question - just for my personal
At a junction box, why is it bad to step down the gauge of a wire to
match the draw of the load on that wire?
In my case, if I had 12 gauge wire to a junction box, why would 14
gauge from the box to the individual heaters be a violation? If each
is only capable of drawing a few amps, and the "pipe" to the box is
I asked an actual electrician about this once, and he said it was
because the NEXT silly SOB might add yet something else to that leg of
the circuit. (Hey! I can grab power from that box right there! etc...)
There is nothing wrong with that, but (with a few exceptions*) the
breaker has to protect the smallest sized wire. So with a long run
of 12 gauge wire (to reduce voltage drop) that then taps off with a
14 gauge wire, you need a 15A breaker.
*there are some exceptions, like the "10 foot tap rule" which might
be used for a kitchen with a split cooktop and oven on the same 40A
I can't answer specifically being electrically challanged (grin), but i do
know when we had our sunroom install, we opted to have 2 of the outlets
direct to my under-utilized electrical service box. The house was upgraded
from 100 amp to 200 amp service about 15 years ago. The electricians smile
when they see the box as apparently we have oodles of excess there. Enough
to run plenty more outlets direct without 'sistering'.
Hence I have 2 outlets in the sunroom each on their own line, and a reserved
line set aside if we want to run a 240V back there for a powerful heater. I
don't know enough to say more other than we asked both be able to run
anything at the same time with a standard 3 prong plug such as an accessory
AC unit or accessory heater. Obviously we wouldnt be heating and cooling at
the same time, but you get the drift. I've used my 1500watt heater with no
problems. When it gets really cold, I also plug in (other outlet) the
monster radient heater to take the chill off fast.
This summer, we had an extra line run as well for the garage heater. Heats
400sqft, set at lowest to keep pipes from freezing. It's all on it's own
circuit too (GFCI not required but we did that for added safety as its other
side of the kitchen sink with water lines over it).
Thought I would finish the story here. We decided to keep the 1000
watt/ 240V heater unit since there would be no load issues with the
I ran a new circuit with 14/2 Romex to the heater location, leaving
six feet of wire hanging beside the panel. I bought and wired the
(internal) thermostat for the heater according to the supplied
diagram, and bought the compatible 2 pole 15 amp circuit breaker.
My electrician friend visited - he verified my thermostat wiring,
checked the wire routing, wired and installed the new circuit breaker
all in about 10 minutes. Works like a champ.
The whole thing took a while to figure out, but little time to
implement. We now have warm floors when needed in the kitchen. Tnx
to everybody who helped out.
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