On Tuesday, August 18, 2020 at 8:59:18 PM UTC-4, J. Clarke wrote:
On Tue, 18 Aug 2020 17:33:19 -0700 (PDT), Brian Welch
wrote:
On Tuesday, August 18, 2020 at 4:55:54 PM UTC-4, DerbyDad03 wrote:
On Tuesday, August 18, 2020 at 4:30:20 PM UTC-4, Brian Welch wrote:
On Tuesday, August 18, 2020 at 3:04:41 PM UTC-4, DerbyDad03 wrote:
On Tuesday, August 18, 2020 at 10:31:10 AM UTC-4, dpb wrote:
On 8/17/2020 9:27 PM, Bill wrote:
Scott Lurndal wrote:
Bill writes:
I think it goes without saying that you should be running 20 amp
circuits (12 gauge wire), doesn't it? Use 15 amp for the lighting.
Or even AWG 10 for the 20A circuits if the run is long enough.
Just curious, what length (in feet) would justify that?
Surprisingly short if use full current ratings -- 20A @ 120V is 2% drop
at 36 ft for #12, 57 ft for #10. For 240V, double the distance (altho
rounding the numbers in the table are 71/113 instead of 72/114).
I found one calculator that said use 10 AWG at 16' for full 20 amps
at 120V, 1% drop.
What I don't like is that many of the calculators are strictly formula based
and don't factor in "code" in any way. Shorten the length enough and you can
use 14 AWG for a 20 amp draw. You'd think they'd include an "IF" clause that
didn't allow the calculator to go below the minimum gauge allowed based on
the amperage entered.
Not an electrician and do not play one on TV.
The possible flaw in your argument re 14ga/20amp is (right or wrong, willing to learn) is what happens if a future homeowner decides to extend that circuit w/add'l outlets/load. Does that affect the safety of the installation?
TIA...
I'm not sure what you mean by "your argument re 14ga/20Amp".
I'd *never* argue for or even suggest using 14 AWG for a 20 amp circuit.
Nowhere in the NEC is that allowed.
I was pointing a *flaw* in some of the calculator that I tried. They appear to
ignore code and return 14 AWG for a "short" run even if the user entered 20 amp
as the maximum draw. I'm saying that the calculators should include limits
and never return a result that would violate code.
Understood, sorry for any misunderstanding...
It really depends on what you're calculating. If you're calculating
6" pigtails for an internal connection, 14 may be fine.
This site calculates 14 AWG for a 20 amp circuit up to 56', allowing up to
3% voltage drop.
http://www.csgnetwork.com/wiresizecalc.html
The description says "Our calculator yields results that are within code in
most locations however we advise you to check your local electrical code."
Am I wrong that the NEC requires 12 AWG for all circuits protected by a
20 AMP breaker, which I would assume would be the case if you expected
a maximum draw of 20 amps?