In article , D Smith wrote:
(Doug Miller) writes:

In article , sylvan butler
wrote:
On Sat, 20 Jan 2007 13:42:27 GMT, Doug Miller wrote:
In article , sylvan
butler
wrote:

Since the L14-30 is a 30amp system, if you use 20amp outlets on each
leg, you may draw 50% more power thru an outlet than it is designed to
handle.

How do you figure that?

What is the amperage rating on an L14-30? 30 amps.

What is the amerage rating on a standard "duplex" outlet? 15 or 20 amps.

How do you propose plugging a 30A device into a 15A or 20A receptacle?

IIRC, his original proposal was to wire this system to several outlets.
Let's see: 15A off the toaster oven in the top plug, 15A off the hair
dryer in the bottom plug, 15A off the table saw in the plug on the other
wall, 15A off the garage door opener running off the extension cord so he
can get his car out of the house.... Do we see anything that adds up to
over 30A here?

Nothing that overloads any of the *receptacles* -- which was the claim I was
objecting to: "... you may draw 50% more power through an outlet that it was
designed to handle" is utter nonsense.

...saying nothing about the defective toaster oven that shorts out and
draws 29A all on its own through its 15A plug...

Of course, it's completely Code-compliant to install a 15A receptacle on a 20A
circuit anyway, and your hypothetical toaster would cause just as big a
problem under that circumstance, too.


Unless he has something that splits the incoming 30A up between several
15A breakers (which I don't remember him planning to do, but he may
have...) that feed different outlets (e.g. he feeds a panel), then he is
looking for trouble.



be up to code?

Probably not.

Why not? What article is it in violation of?

I'm not going to waste my time trying to find the reference. But if you
think you can safely wire a 20amp outlet into a 30amp circuit, please go
right ahead.

Helloooooo.... When you split a 30A 240V circuit into two 120V circuits, you
do *not* get two 30A 120V circuits. You get two 15A circuits.

30A from one hot to neutral, 30A from other hot to neutral. All current
runs through the hots, with nothing on the neutral, as the load is
balanced. (If it isn't balanced, the neutral carries the _difference_
between the two loads.)

Yeah, you're right -- I can't imagine what I was thinking when I wrote that.
It's nuts.

But he still isn't going to overload any individual receptacles, unless he can
figure out a way to force a 30A plug into a 20A receptacle.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.