At this home there is a 20 amp breaker in the electrical panel that is penc
il labeled as for the dishwasher and garbage disposal. At the junction box
on the kitchen wall near the sink we see the 12 gauge wire feeds from the p
anel. Three 14 gauge wires, hot-black/neutral-white/ground-green, are route
d from this box to another junction box underneath the sink through conduit
. A whip from the dishwasher is hardwired to the wires under the sink.
We want to add a GE half horsepower garbage disposal that is suppose to dra
w only 4.5 amps. Can we just pull another hot 14 gauge wire for the garbage
disposal and use the existing white neurtal already there for the dishwash
er? Does it matter whether 14 gauge is used rather than 12 gauge wires for
All the wires should usually be #12 BUT if you are serving a pure
motor load like the disposal, you could use #14. (125% of FLA) Not so
with the dish washer since it is not a pure motor load.
Whether they can share the circuit would depend on the nameplate
rating of the dishwasher.
Take 125% of the largest load and 100% of the other one. It has to be
20 or less.
On 12/8/2013 7:26 PM, email@example.com wrote:
I believe I've seen them on the same circuit before but I haven't done
house wiring as an electrician in years and the dishwasher here is on a
separate circuit. I'd have to go look at the outdoor breaker panel to
determine what size breaker and wire it is because I didn't install it.
Besides, I have a bit of trouble walking and it's raining hogs and frogs
outside right now. ^_^
On Sun, 08 Dec 2013 16:35:48 -0500, firstname.lastname@example.org wrote:
Not illegal or even unusual.
If you had a post light and a gate opener at the end of a long
driveway you might want 12ga on your 15a circuit going down there,
just for the voltage drop and between the opener and the light, 14
would be fine.
Is it worth doing to save a nickel on this 3' of 14. Not really but
it might not be illegal.
Bear in mind there are a few jurisdictions in the US that won't let
you use 14 for anything but that is a local amendment, made by idiots.
On 12/8/2013 5:54 PM, email@example.com wrote:
The city engineering department around here wants the breaker sized for
the wire. It's possible that in the warmer temperatures we experience
here in Alabamastan, the wire and breakers must be derated to deal with
it to prevent nuisance tripping. I have checked the temperatures of many
electrical panels with my infrared thermometer and they get quite hot at
times under normal loads. Of course I'm looking for that hottest breaker
which could indicate a bad connection. ^_^
On 12/8/2013 8:57 PM, firstname.lastname@example.org wrote:
I believe gfretwell is/was an electrical inspector and he is going by
the NEC. The problem comes in when you have a city engineering
department that has its own interpretation of the National Electrical
Code like where I live. Anyone getting an inspection must do as the
inspector demands even if you believe him/her/it to be wrong. You can
sometimes pull out the code book and win an argument but unless it's an
absolutely insane demand, it's best not to argue with the inspector. ^_^
On Sun, 08 Dec 2013 21:57:40 -0500, email@example.com wrote:
"The NEC does not address what an unqualified person might do". I got
that straight from the NFPA on a proposed change about something
I suppose I could blow everyone's mind by saying it is legal to use a
40a breaker on 14 ga wire if you are serving a 1HP single phase 120v
motor with internal overload protection.
It is a common question in the inspector test.
FLA is 16a (Table 430.248)
125% of that is 20a (430.22)
Table 316.16 says a 14 ga copper wire is OK for 20a in the 60c column.
The over current device can be up to 250% of FLA. 16 x 2.5 = 40a
(table 430.52) if the motor has overload protection.
On Monday, December 9, 2013 7:01:33 PM UTC-5, firstname.lastname@example.org wrote:
The overload protection in this case is inside the motor
itself. It's a common misconception among home inspectors too.
Some of them see a 50A breaker going to an AC compressor and assume
that it has to use the same size conductor that you would use
for a 50A oven. They see a smaller conductor and flag it,
though it's 100% code compliant to use a smaller conductor,
within the rating of the AC unit specs.
On Tuesday, December 10, 2013 1:05:44 PM UTC-5, email@example.com wrote:
You know, you're remarkably arrogant for someone who knows so
little. You didn't even know how motor loads are sized.
Gfre, who is/was an electrical inspector told you that
you were wrong.
And what I just told you is correct. The overload protection
is in the motor. That protects the motor and the *wiring*
from overload, because the motor is the load. Capiche?
Or would you like to dig your hole deeper?
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