Chassis wiring vs. power transmission

Aaron Fude

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Jul 29, 2009, 11:41:25 PM7/29/09

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I'm learning to interpret the table here (about 1/3 of the way down):

http://www.powerstream.com/Wire_Size.htm

What are examples "Chassis wiring" and what is "power transmission"?

My specific situation: I have a 70 foot run of 10/3 wire to a subpanel
inside my house. How many amps can I have on that subpanel?

Thanks,

Aaron

Smitty Two

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Jul 30, 2009, 12:31:21 AM7/30/09

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In article <h4r4p9$trf$1...@news.eternal-september.org>,
Aaron Fude <aaro...@gmail.com> wrote:

Chassis wiring is *short* lengths of wiring inside a machine. I use 16
gauge in an industrial food processor that draws about 15 amps. That's
well under the chassis wiring limit, but far more than you could draw
through house wiring. It's all about ohms per foot.

Aaron Fude

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Jul 30, 2009, 1:15:13 AM7/30/09

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So then the table tells me that I can only have 15amps in my subpanel.
That can't be right.

Aaron Fude

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Jul 30, 2009, 1:15:36 AM7/30/09

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Thanks for your insightful response, BTW.

dpb

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Jul 30, 2009, 1:26:46 AM7/30/09

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Aaron Fude wrote:
...

> So then the table tells me that I can only have 15amps in my subpanel.
> That can't be right.

At <=2% voltage drop @120V, yes...240V is 30A @75 ft which would be the
subpanel supply voltage I would presume.

--

Smitty Two

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Jul 30, 2009, 1:40:55 AM7/30/09

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In article <h4ra92$dg1$1...@news.eternal-september.org>,
Aaron Fude <aaro...@gmail.com> wrote:

From the notes accompanying that table:

"The Maximum Amps for Power Transmission uses the 700 circular mils per
amp rule, which is very very conservative."

"NOTE: For installations that need to conform to the National
Electrical Code, you must use their guidelines."

DAGS "NEC wire ampacities" or similar for links to other tables, or wait
for the resident a.h.r. code junkies for further info, but yes, I'm
pretty sure you can pull more than 15 amps through 10 AWG wire.

Wayne Whitney

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Jul 30, 2009, 12:28:41 PM7/30/09

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On 2009-07-30, Aaron Fude <aaro...@gmail.com> wrote:

> My specific situation: I have a 70 foot run of 10/3 wire to a
> subpanel inside my house. How many amps can I have on that subpanel?

NEC 2008 section 240.4(D):

(D) Small Conductors. Unless specifically permitted in 240.4(E) or
(G), the overcurrent protection shall not exceed that required by
(D)(1) through (D)(7) after any correction factors for ambient
temperature and number of conductors have been applied.

[ . . .]

(7) 10 AWG Copper. 30 amperes

Cheers, Wayne

ehp...@gmail.com

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Feb 23, 2017, 12:27:43 AM2/23/17

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hi, must be a solenoid treat like a "chassis wiring" or like a power transmission? (my english is bad)

gfre...@aol.com

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Feb 23, 2017, 1:12:41 AM2/23/17

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On Wed, 22 Feb 2017 21:27:34 -0800 (PST), ehp...@gmail.com wrote:

>hi, must be a solenoid treat like a "chassis wiring" or like a power transmission? (my english is bad)

Without more details I would say chassis wiring if it is in a listed
enclosure.
What context are we talking about