On Mon, 21 Jul 2014 20:43:21 -0700 (PDT), email@example.com wrote:
OK good deal but I bet you still only need 2 current carrying
conductors and a ground (10 ga)
A/C units are usually just 120v or 240v.
My guess is if they really are saying 50a and 6ga wire this is a heat
pump with toaster heat backup.
If you used THHN/THWN in a raceway you could use #8 (in the 75c
column) for 50a with a 10g ground. That fits in a 3/4" raceway. You
are going to need a wet location wiring method going to the condenser
anyway. Romex won't work.
Romex is limited to 60c.
On 7/21/2014 6:30 PM, firstname.lastname@example.org wrote:
air conditioner system.
(unoccupied) 3/4" size punch outs left; but there
is a 1/2" punch out. It is possible for me to fit
this 6-3 with ground in there, but does anyone know
whether this is prohibited by the NEC?
On a practical note, I'd be sure to have a Romex
in the punch out. Just to run the wire through the
hole leaves the risk of the panel metal wearing
through the insulation and causing a short.
How many tons of cooling? I remember using 10 AWG
for 2 1/2 ton system one time.
On Tuesday, July 22, 2014 6:43:07 AM UTC-4, Stormin Mormon wrote:
I think Gfre might be on to something when he suggested it might
also have resistance electric heat and maybe that's why the need
for #6. If the OP gives the make and model we could probably find
the specs and install intructions and I'd like to take a look.
I'm still skeptical that a mini-split could really need #6. As I said,
my 5 ton central AC uses #8, but being AC only, it doesn't have any
You can enlarge the 1/2" punch outs to accept a 3/4" cable clamp.
The ideal way to do this is with a knockout punch, but they tend to be
rather expensive for a one time job. Step drills will also work, but
they're almost as expensive as a knockout punch.
I went through this recently with my garage heater and used a metal nibbler
to enlarge the hole. You can see photos on this page ("Relocating the power
cord" about halfway down the page):
Be sure to turn off the main breaker before you start working in the panel,
and vacuum up any little metal bits that may fall inside the panel.
That's not all you missed, and no, your reply is not corrected, it's still wrong because you're
still missing the main point that whether the cable physically fits or not is meaningless. The
ONLY thing that counts is whether the connector is listed for such use.
The main reason for emphasizing the distinction is so that newbies are not mislead by your
incorrect post into thinking that -- for example -- because they can fit three 14-2 cables in a
standard Romex connector it must be OK to do so.
On Tuesday, July 22, 2014 11:49:38 AM UTC-4, Doug Miller wrote:
Another good point. Would be a shame to pay for 3 conductors and then
wind up not even having a place to connect one. I'd be curious to learn
the make/model of this beast so we can see the install instructions. I'm
still skeptical of 6 gauge for a mini-split.
Hi, I'm the OP.
The unit is a Sea Breeze SMZ42H46ZOGX.
The instruction manual and even the promo literature explicitly calls out a
6AWG Stranded 3 Conductor cable, with a 50amp breaker.
Weird thing is that of the 3 conductors, it appears to send one to ground (
g). And since I have a "6-3 Romex NM-B with ground", I now seem to have an
extra (unused) wire... the neutral.
Do you agree?
On Thu, 31 Jul 2014 20:25:57 -0700 (PDT), email@example.com wrote:
When I look this up I do see where the manual says you need 6 ga wire
but it also says "Minimum circuit ampacity 26a" which would be 10
gauge copper according to the NEC. It really sounds like the chinese
book writer does not understand the electrical code.
Does the label on the outside unit say "26a" on the minimum circuit
Maximum over current protection probably says "50a"
Sounds like you're suggesting they overcompensated, but I will not be so bold as to disregard a specification that explicitly says use 6AWG with a 50Amp breaker.
From the literature:
Rated Voltage & Frequency and Phase :208-230 / 1PH
Min./ Max. Operating Voltage :187 / 253 VAC
Circuit Breaker Size (A): 50
Min. Circuit Ampacity (A): 26
Wiring (Outdoor unit to Power Disconnect): 3C- 6 AWG (minimum)
On Thu, 31 Jul 2014 22:12:19 -0700 (PDT), firstname.lastname@example.org wrote:
If the label on the unit says this, an electrical inspector will
accept 10 ga wire. I doubt he would ever look at your book.
You certainly never get in trouble spending more money on wire tho, as
long as the box and the raceway (if used) is big enough
Ok here is the logic
The manufacturer probably specified a 50 amp breaker to reduce trips during the startup inrush. You all know an a/c has a large inrush current.
Now if you are using a 50 amp breaker you MUST use #6ga or larger wire to be safe and meet code.
The breaker and wire size must match to be safe.
But it does seem the directions were confusing re the number of conductors needed.
6-2 is three total conductors, 2 that carry current and one safety ground.
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