On Saturday, August 2, 2014 5:06:41 PM UTC-4, wrote:
On Sat, 02 Aug 2014 15:59:53 -0400, wrote:
On Sat, 02 Aug 2014 15:51:59 -0400, wrote:
On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
wrote:
wrote in :
And remember - if the unit draws a constant 26 amps, it is over-spec
for a 30 amp circuit (maximum 80% rated current for continuous use)
The term "continuous" has a clear, specific definition in the Code -- and an air conditioner
does not meet that definition.
You really should stop trying to give electrical advice.
OK - what does "continuous" mean? What minimum duty cycle is
required for it to be "continuous"? How long does the air conditioner
run on the hottest day of the year? Is the running current not
"continuous" in this case? Starting amps don't count. Do you KNOW what
the steady state running current of the AC unit in question is??
Continuous is 3 hours in the NEC.
My assumption is the AC unit would draw 26 amps for more than 20 min
utes at a time, up to full time operation, it is to be connected with
a 3 conductor (including ground) flexible stranded cable.
Your assumptions are no more valid than mine, whatever they are -
unless you KNOW what current the unit draws and KNOW it will never
approach 100% duty cycle
It is really not even a factor here. The "minimum circuit ampacity" is
an engineered value based on that particular piece of equipment and
takes into account all applicable factors.
In this case a 10 gauge copper wire will fulfill that requirement.
So why does the instruction specify a #6??????
If the manufacturer's UL listing spec requires a #6, it doesn't meet
code to connect with a #10.
We don't have access to the UL listing spec. All we have are the eqpt
rating plate and one page of the install manual. That one page, was
obviously written by a complete buffoon. They call for #6 and in the
diagram call it a cord. How many outside AC condenser/compressor units
have you seen installed on cords?
And then they call for 4 conductor cord. Lets take that literally too.
So, we have 4 conductors and a ground? WTF? OK, whooops, I guess
they really meant 3 conductors plus ground. So we get a big honking
#6 cord, with 3 conductors plus ground. Whooops! They only show two conductors actually used, ie like you'd expect for a 240V AC unit. So
I guess the extra one is for good luck, but heh, they said to do it
righ? In other words, whoever wrote that manual, proably in China,
didn't know WTF they were talking about.
On the other hand, we do know the unit is rated at 3.7 tons. That
the rated input power is 4600 watts and that the eqpt label says the
min circuit ampacity is 26A. All that says #6 is nuts and that 10g
would suffice. Since 26A is close, I'd go with #8. And I would not
use a cord, which I don't think would even pass code here. I'd put
THWN, #8, 2 conductors plus ground, inside liquidtight. The OP as
always, can do as he chooses.