Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
My main panel doesn't seem to have any spare (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?
All advice (and NEC references) appreciated!
Regards,
Theodore.

wrote in
:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air
conditioner system. My main panel doesn't seem to have any spare
(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? All advice (and NEC references) appreciated!

I doubt very much that this would meet Code. First of all, you can't just pass the cable
through the knockout hole -- for the protection of the cable and the connections, Code
requires some sort of fitting on the hole (e.g. a cable clamp aka "Romex connector") which
secures the cable to the box. And I can't imagine that any fitting which would fit a 1/2"
knockout is listed for use with anything as large as 6-3; for example, the Romex connectors
used with 1/2" knockouts are listed for 14-2 through 10-3.

Does the panel have any vacant 1" knockouts? Or can you ream the 1/2" hole to 3/4"?

Doug Miller wrote:
wrote in
:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air
conditioner system. My main panel doesn't seem to have any spare
(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? All advice (and NEC references) appreciated!

I doubt very much that this would meet Code. First of all, you can't just pass the cable
through the knockout hole -- for the protection of the cable and the connections, Code
requires some sort of fitting on the hole (e.g. a cable clamp aka "Romex connector") which
secures the cable to the box. And I can't imagine that any fitting which would fit a 1/2"
knockout is listed for use with anything as large as 6-3; for example, the Romex connectors
used with 1/2" knockouts are listed for 14-2 through 10-3.

Does the panel have any vacant 1" knockouts? Or can you ream the 1/2" hole to 3/4"?

Hi.
The length of cable must be long, otherwise wouldn't 8-3 do? Enlarging
hole is easy using rimmer, cabinet is not really heavy gauge steel.

On Monday, July 21, 2014 7:17:12 PM UTC-4, Doug Miller wrote:
wrote in

:



Hi,

I'm running a 6-3 Romex NM-B with ground for my new air

conditioner system. My main panel doesn't seem to have any spare

(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? All advice (and NEC references) appreciated!



I doubt very much that this would meet Code. First of all, you can't just pass the cable

through the knockout hole -- for the protection of the cable and the connections, Code

requires some sort of fitting on the hole (e.g. a cable clamp aka "Romex connector") which

secures the cable to the box. And I can't imagine that any fitting which would fit a 1/2"

knockout is listed for use with anything as large as 6-3; for example, the Romex connectors

used with 1/2" knockouts are listed for 14-2 through 10-3.



Does the panel have any vacant 1" knockouts? Or can you ream the 1/2" hole to 3/4"?

Aside from that, does he really need #6 for an AC? Presumbably a home AC?
I have a 5 ton, which I believe is the largest made and it's rated for #8. I
wonder if he's sizing based on breaker, instead of sizing based on the
install instructions and eqpt rating. Meaning I have a 50 amp breaker on
my 8 gauge, 5 ton and it's to code because it's a motor load, not an oven.

On 07/21/2014 06:43 PM, wrote:
On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), wrote:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
My main panel doesn't seem to have any spare (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?
All advice (and NEC references) appreciated!
Regards,
Theodore.

Get one of these

http://www.harborfreight.com/knockou...kit-91201.html





I agree, I'd punch it out.



(sorry if you got an email, I hit the wrong button)

On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), wrote:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
My main panel doesn't seem to have any spare (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?
All advice (and NEC references) appreciated!
Regards,
Theodore.
Can you get the 6-3 cable through the required cable connector, is
the big question. If you can fit the 6-3 into the connector that
threads into the 1/2" knockout, you are gold. If not you will need a
knockout punch to enlarge the hole to 3/4" size (Greenlee punch)

On Mon, 21 Jul 2014 17:23:30 -0600, Tony Hwang
wrote:

Doug Miller wrote:
wrote in
:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air
conditioner system. My main panel doesn't seem to have any spare
(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? All advice (and NEC references) appreciated!

I doubt very much that this would meet Code. First of all, you can't just pass the cable
through the knockout hole -- for the protection of the cable and the connections, Code
requires some sort of fitting on the hole (e.g. a cable clamp aka "Romex connector") which
secures the cable to the box. And I can't imagine that any fitting which would fit a 1/2"
knockout is listed for use with anything as large as 6-3; for example, the Romex connectors
used with 1/2" knockouts are listed for 14-2 through 10-3.

Does the panel have any vacant 1" knockouts? Or can you ream the 1/2" hole to 3/4"?

Hi.
The length of cable must be long, otherwise wouldn't 8-3 do? Enlarging
hole is easy using rimmer, cabinet is not really heavy gauge steel.
I assume you mean a reamer - which leaves all kinds of conductive
swarf all through the panel. The only RIGHT way to do it is with a
"knoclut punch" - aften referred to by the most common brand - a
"greenlee punch" Any electrician worth his salt will have one. All you
get that way is a metal ring.

On Mon, 21 Jul 2014 19:43:33 -0400, wrote:

On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), wrote:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
My main panel doesn't seem to have any spare (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?
All advice (and NEC references) appreciated!
Regards,
Theodore.

Get one of these

http://www.harborfreight.com/knockou...kit-91201.html

That will do the job. Wouldn't want to make my living with it, but it
will make a few holes, for sure. A lot cheaper than Greenlee

Tony Hwang wrote in :

The length of cable must be long, otherwise wouldn't 8-3 do?

Conductor size is determined by amperage, not by length.

Enlarging hole is easy using rimmer,

LMAO! The tool he needs is a *reamer*. A "rimmer" is something altogether different.

trader_4 wrote in news:33f37dfc-9d21-481f-9d0e-b98ec7ca68b6
@googlegroups.com:

Aside from that, does he really need #6 for an AC? Presumbably a home AC?
I have a 5 ton, which I believe is the largest made and it's rated for #8. I
wonder if he's sizing based on breaker, instead of sizing based on the
install instructions and eqpt rating. Meaning I have a 50 amp breaker on
my 8 gauge, 5 ton and it's to code because it's a motor load, not an oven.

Whether he needs AWG-6 or AWG-8 is not really relevant -- neither one is listed for use with
any Romex connector or clamp that I'm aware of which will fit in a 1/2" knockout.

Another question for the OP: do you really need 6-3 (or 8-3, as the case may be) for an air
conditioner? If it's central AC, it's almost surely a pure 240V load, and 2-conductor cable will do
-- and if it's a window AC, 10-3 is almost surely sufficient.

wrote in :

On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), wrote:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
My main panel doesn't seem to have any spare (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?
All advice (and NEC references) appreciated!

Can you get the 6-3 cable through the required cable connector, is
the big question. If you can fit the 6-3 into the connector that
threads into the 1/2" knockout, you are gold.

WRONG. The big question is whether the required cable connector is listed for use with 6-3
cable. If the connector is not listed for use with 6-3 cable, it's a Code violation to use it for
that, whether the cable fits or not.

On 07/21/2014 06:30 PM, wrote:
Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.

That must be one bad ass air conditioner. Wouldn't want your electric bill.

On Tue, 22 Jul 2014 01:10:49 +0000 (UTC), Doug Miller
wrote:

trader_4 wrote in news:33f37dfc-9d21-481f-9d0e-b98ec7ca68b6
:

Aside from that, does he really need #6 for an AC? Presumbably a home AC?
I have a 5 ton, which I believe is the largest made and it's rated for #8. I
wonder if he's sizing based on breaker, instead of sizing based on the
install instructions and eqpt rating. Meaning I have a 50 amp breaker on
my 8 gauge, 5 ton and it's to code because it's a motor load, not an oven.

Whether he needs AWG-6 or AWG-8 is not really relevant -- neither one is listed for use with
any Romex connector or clamp that I'm aware of which will fit in a 1/2" knockout.

Another question for the OP: do you really need 6-3 (or 8-3, as the case may be) for an air
conditioner? If it's central AC, it's almost surely a pure 240V load, and 2-conductor cable will do
-- and if it's a window AC, 10-3 is almost surely sufficient.
Wire size is PRIMARILY dictated by load, but cable length comes into
play due to excessive voltage drop. You can never go wrong going one
size oversized.

On Tue, 22 Jul 2014 01:14:05 +0000 (UTC), Doug Miller
wrote:

wrote in :

On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), wrote:

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
My main panel doesn't seem to have any spare (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?
All advice (and NEC references) appreciated!

Can you get the 6-3 cable through the required cable connector, is
the big question. If you can fit the 6-3 into the connector that
threads into the 1/2" knockout, you are gold.

WRONG. The big question is whether the required cable connector is listed for use with 6-3
cable. If the connector is not listed for use with 6-3 cable, it's a Code violation to use it for
that, whether the cable fits or not.
Well, you show me a romex connector that will take a 6/3 cable that
isn't listed for use with 6/3 and you may have a point. The POINT is,
there is no romex connector that WILL accept a 6/3 - listed or not..

On Mon, 21 Jul 2014 22:19:30 -0400, wrote:
I missed the 1/2" requirement in my last reply - this is the corrected
reply.

Can you get the 6-3 cable through the required cable connector, is
the big question. If you can fit the 6-3 into the connector that
threads into the 1/2" knockout, you are gold.

WRONG. The big question is whether the required cable connector is listed for use with 6-3
cable. If the connector is not listed for use with 6-3 cable, it's a Code violation to use it for
that, whether the cable fits or not.
Well, you show me a 1/2 inch romex connector that will take a 6/3 cable that
isn't listed for use with 6/3 and you may have a point. The POINT is,
there is no romex connector that WILL accept a 6/3 AND fit a 1/2" hole - listed or not..

Hi, I'm the OP.
Yes, the mini split a/c system specs explicitly call for a 50amp breaker and #6 AWG (although I shudder to think that it'll actually use that much, with a 16 SEER).

I think I answered my own question by finding several "conduit fill charts" online that say 1/2" conduit can only have 2 #6 wires, so rules are there to keep me safe and I'm fine with that.

I also failed to notice one last 3/4" knock-out, so I'll be using that one.
Many thanks to all the good technical solutions and suggestions!
Regards,
Theodore.

On 7/21/2014 6:30 PM, wrote:
Hi,
I'm running a 6-3 Romex NM-B with ground for my new
air conditioner system.
My main panel doesn't seem to have any spare
(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?
All advice (and NEC references) appreciated!
Regards,
Theodore.

On a practical note, I'd be sure to have a Romex
connector

http://www.contractcleanersupplies.c...-connector.jpg
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.


--
..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On 7/21/2014 8:31 PM, wrote:
The length of cable must be long, otherwise wouldn't 8-3 do? Enlarging
hole is easy using rimmer, cabinet is not really heavy gauge steel.
I assume you mean a reamer - which leaves all kinds of conductive
swarf all through the panel. The only RIGHT way to do it is with a
"knoclut punch" - aften referred to by the most common brand - a
"greenlee punch" Any electrician worth his salt will have one. All you
get that way is a metal ring.


HF sells step bits which can be used to enlarge
the hole. Of course, you need a shopvac in action
at the same time to catch the chips.

Instead of a rimmer, use a knoclut punch. Amazing,
one good misssspelled word desserves anothher.


..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On 7/21/2014 11:43 PM, wrote:
Hi, I'm the OP.
Yes, the mini split a/c system specs explicitly call for a 50amp breaker and #6 AWG (although I shudder to think that it'll actually use that much, with a 16 SEER).

I think I answered my own question by finding several "conduit fill charts" online that say 1/2" conduit can only have 2 #6 wires, so rules are there to keep me safe and I'm fine with that.

I also failed to notice one last 3/4" knock-out, so I'll be using that one.
Many thanks to all the good technical solutions and suggestions!
Regards,
Theodore.

So, what's the tons or BTU that
needs such a big wire?


..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On Tuesday, July 22, 2014 6:43:07 AM UTC-4, Stormin Mormon wrote:
On 7/21/2014 6:30 PM, wrote:

Hi,

I'm running a 6-3 Romex NM-B with ground for my new

air conditioner system.

My main panel doesn't seem to have any spare

(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?

All advice (and NEC references) appreciated!

Regards,

Theodore.



On a practical note, I'd be sure to have a Romex

connector



http://www.contractcleanersupplies.c...-connector.jpg

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.



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
resistance heat.

On 7/22/2014 8:37 AM, trader_4 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
resistance heat.


OP had been providing some info, but now
I sense some resistance. We'll have to amp
it up a bit.

--
..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On 07/21/2014 10:43 PM, wrote:
Hi, I'm the OP.
Yes, the mini split a/c system specs explicitly call for a 50amp breaker and #6 AWG (although I shudder to think that it'll actually use that much, with a 16 SEER).

I think I answered my own question by finding several "conduit fill charts" online that say 1/2" conduit can only have 2 #6 wires, so rules are there to keep me safe and I'm fine with that.

I also failed to notice one last 3/4" knock-out, so I'll be using that one.
Many thanks to all the good technical solutions and suggestions!
Regards,
Theodore.




Though your A/C is not likely to draw anywhere near 50 amps
continuously, it will have a very high initial startup current.

By using #6 wire the voltage drop should be minimal.

Hi Theodore,

I'm running a 6-3 Romex NM-B with ground for my new air conditioner
system. My main panel doesn't seem to have any spare (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?

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):

http://www.watsondiy.com/heater.htm

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.

Good luck!

Anthony Watson
www.mountainsoftware.com
www.watsondiy.com

On Tuesday, July 22, 2014 10:08:58 AM UTC-4, philo* wrote:
On 07/21/2014 10:43 PM, wrote:

Hi, I'm the OP.

Yes, the mini split a/c system specs explicitly call for a 50amp breaker and #6 AWG (although I shudder to think that it'll actually use that much, with a 16 SEER).



I think I answered my own question by finding several "conduit fill charts" online that say 1/2" conduit can only have 2 #6 wires, so rules are there to keep me safe and I'm fine with that.



I also failed to notice one last 3/4" knock-out, so I'll be using that one.

Many thanks to all the good technical solutions and suggestions!

Regards,

Theodore.









Though your A/C is not likely to draw anywhere near 50 amps

continuously, it will have a very high initial startup current.



By using #6 wire the voltage drop should be minimal.

It's also minimal with #8 and the percent voltage drop difference
between #6 and #8 is insignificant. Which is why you can wire even a
5 ton AC with number #8.

wrote in :

On Mon, 21 Jul 2014 22:19:30 -0400, wrote:
I missed the 1/2" requirement in my last reply - this is the corrected
reply.

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.

wrote in
:

Hi, I'm the OP.
Yes, the mini split a/c system specs explicitly call for a 50amp
breaker and #6 AWG (although I shudder to think that it'll
actually use that much, with a 16 SEER).

Do you really need 6-3 cable, though? Or will 6-2 suffice?

On Tuesday, July 22, 2014 11:49:38 AM UTC-4, Doug Miller wrote:
wrote in

:



Hi, I'm the OP.

Yes, the mini split a/c system specs explicitly call for a 50amp

breaker and #6 AWG (although I shudder to think that it'll

actually use that much, with a 16 SEER).



Do you really need 6-3 cable, though? Or will 6-2 suffice?

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.

On 07/22/2014 09:42 AM, trader_4 wrote:









Though your A/C is not likely to draw anywhere near 50 amps

continuously, it will have a very high initial startup current.



By using #6 wire the voltage drop should be minimal.

It's also minimal with #8 and the percent voltage drop difference
between #6 and #8 is insignificant. Which is why you can wire even a
5 ton AC with number #8.




I am sure you can but if the mfg says #6 I'd just go with what they say.

On 07/22/2014 07:45 AM, Stormin Mormon wrote:
On 7/22/2014 8:37 AM, trader_4 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
resistance heat.


OP had been providing some info, but now
I sense some resistance. We'll have to amp
it up a bit.





Per Ohm's Law, to increase the current you will need to raise the voltage.

On 7/22/2014 2:22 PM, philo wrote:
On 07/22/2014 07:45 AM, Stormin Mormon wrote:
On 7/22/2014 8:37 AM, trader_4 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
resistance heat.


OP had been providing some info, but now
I sense some resistance. We'll have to amp
it up a bit.





Per Ohm's Law, to increase the current you will need to raise the voltage.

Well, figuring a static load. What did you say?
I can't hear you with all that static.

--
..
Christopher A. Young
Learn about Jesus
www.lds.org
..

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 (http://i899.photobucket.com/albums/a...s3e1fd5ca.jpg). 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?

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 literatu

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)

It's strictly a heat pump/AC.
No resistance heat that I can see on the specs.

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.

Mark

On Friday, August 1, 2014 7:54:14 AM UTC-4, wrote:
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.

I'm surprised it took this long for someone to post this, which is
wrong. Breakers for equipment with motor loads are not sized like
a circuit for receptacles or a heater. It's perfectly permissible to
have a 50A breaker on an #8 gauge wire for an AC. The overcurrent
protection is in the eqpt and it's rated for that installation.

I agree with Gfre, whoever wrote that manual, wherever they are located,
(China?), doesn't know what they are doing. Proof that they don't is
clearly demonstrated by them calling for 3 conductor cable, while they
really mean 2 conductor plus ground. Another very curious thing that
I've never seen before, look at what goes from the outside unit to power
the evaporator unit(s) that shown in the posted link. And in the spec
they call that 4 conductor. What they are showing looks like 3 conductors
plus ground, all used. So, what they are clearly showing is a
240V only connection coming in to the outside unit, then a 240V connection
*with neutral* leaving it to power the evaporator(s). That seems *very*
strange to me.... It seems like they have established their own neutral,
unconneced to the service neutral, going to the other units.
Any thoughts Gfre?

Regarding the conductor sizing, I agree with Gfre. The spec sheet says
26A min circuit ampacity. The rated power input is 4600W max. Based on that,
10g would be sufficient. Does this thing have backup resistance electric
heat by any chance? I doubt it because it's not in the spec sheet. If
it were my install, I'd go by the rating plate. At 26A, I'd just bump it
up to 8g, 2 conductors. If anything, I'd say the big honking cable with
an extra unused conductor is more likely to draw an inspectors attention,
because it looks odd and likely a DIY.


In most places this should have a permit. Why not write down what's on the
eqpt tag and take that, the manual, and the spec sheet and go ask the
inspector?




The breaker and wire size must match to be safe.

Wrong.




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.



Mark

And wrong again. 6-2 is TWO conductors, plus a ground. The ground is
*not* a conductor.

trader4 says: " It seems like they have established their own neutral,
unconneced to the service neutral, going to the other units. "

My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.

Side note: kind of strange to me that the indoor units are 220VAC. Call me paranoid, but

trader4 says: " It seems like they have established their own neutral,
unconneced to the service neutral, going to the other units. "

My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.

Side note: kind of strange to me that the indoor units are 220VAC. Call me paranoid, but I wouldn't have minded a true neutral and only 120VAC to each indoor unit.

On Friday, August 1, 2014 9:44:01 AM UTC-4, wrote:
trader4 says: " It seems like they have established their own neutral,

unconneced to the service neutral, going to the other units. "



My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.



I was thinking of it strictly in terms of power and the fact that in
the diagram, that wire is marked N(1). Marking it N and having it wired
right there with the two hots, sure strongly suggests it's a neutral.
Do they talk about what that N(1) means at all?

But if those wires are the only link between the outside and inside eqpt,
then I agree signalling would have to go on it. It's even possible it
serves both functions, but if it's like you're suggesting, it makes sense
electrically. But if it's signalling, I wonder what code says about
that? ie, combining signalling, which would normally be low voltage with
240V? I guess it they use 240V to do the signalling, then it's OK, but
they couldn't AFAIK use 24V or similar.

Regarding using 240V to run the evaporators inside the house, I'd have
no problem with that. In Europe, many places, 220 is standard receptacle
voltage. Also, something many folks miss, it's pretty hard to wind up
with 240V going through you. You'd have to make contact with *both* hot
legs. Far more likely is standing in water, touching ground and one hot,
in which case, it's still 120V.

On Friday, August 1, 2014 10:46:28 AM UTC-4, wrote:
On Fri, 1 Aug 2014 06:42:25 -0700 (PDT), wrote:



trader4 says: " It seems like they have established their own neutral,

unconneced to the service neutral, going to the other units. "



My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.



Side note: kind of strange to me that the indoor units are 220VAC. Call me paranoid, but



The mini splits are usually "inverter" designs so they do generate

their own voltages in the unit. I bet the voltages going to each

inside unit are not line voltage at all. The ones I have use a low

voltage (24 or so)

Interesting. I just assumed line voltage in, line voltage out,
which I guess it isn't. As you point out, all they really need is
power for the fan and a communications link of some kind, so how
they do it is up to them.

On Fri, 01 Aug 2014 00:32:34 -0400, wrote:

On Thu, 31 Jul 2014 20:25:57 -0700 (PDT), wrote:

SMZ42H46ZOGX

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
ampacity line?
Maximum over current protection probably says "50a"
26 amps is more than 80% of 30 amps. Generally a circuit should not
excede 80% of the circuit protection rating (fuse or breaker - and I
assume wiring). Also, if I remember and read correctly, the
specification is for a "stranded" wire - which "generally" should be
sized up 1 size. So up one from 10 because it is over 80% circuit
capacity, and up one for stranded would be a #6 stranded cordWhich
would explain the recommendadation - and would allow a #8 solid
conductor.
Still. not hurting anything but the pocketbook using #6, and using
3+ground instead of 2+ground is costing a lot more than the guage
upgrade. Remember - it was talking about a "3 conductor stranded cord"
- which is black/white/green. Using solid cable that is 2+ground -
black, white, and bare.