On Saturday, August 2, 2014 4:01:14 PM UTC-4, wrote:
On Sat, 02 Aug 2014 11:02:16 -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.



Air conditioners are such a specific load that it really requires an

engineer to specify the circuit ampacity and over current protection.

That is why the U/L marking guide specifies this on the label.



Motor loads are subject to the 80% rule but that is 125% of the

nameplate FLA and you use table 310.16 to determine wire size, not

240.4(D)

And if the manufacturer(on the UL label) specifies #6 wire be used

for connection, it does NOT meet code if installed with #8 or #10

Except of course that the manufacturer did not say #6 or any gauge on the
UL label. Nor have I ever seen gauge on a similar label. The governing data
on the eqpt label is the 26A, if he chooses to follow that. The manufacturer
stated #6 gauge in the install manual, which was obviously written by a buffoon, because they don't understand the difference between conductors and
grounds. The install instructions say that it's to be installed with
4 conductors and then they show only a 240V connection, no neutral, just like
you'd expect with any other air conditioner. So, following that, even
after correcting it to 3 conductors, plus ground, you'd have an extra
wire that goes nowhere. Would you follow that too?

That 3.7 ton AC would have to be the most inefficient piece of crap ever
made to need #6. It would be so inefficient, it couldn't meet the min
SEER required today. It also states in the spec that the rated input power
is 4600 watts. 4600 watts = 19 amps. There is nothing there that comes
close to needing 6 gauge wire.