Split A/C unit electrical question

Reply

  #1  
Old 04-29-17, 03:24 PM
S
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 173
Received 0 Votes on 0 Posts
Split A/C unit electrical question

Installing a mini split airconditioner. The power will run thru the attic. Then I planned to run my UF-B down thru the decorative channel along with the tubing and 4-wire 'signal cable' to the outdoor unit and outdoor cutoff switch. It's about a 10ft vertical drop to the outdoor unit. HOWEVER, the instructions say "do not intertwine or cross the signal cable with any other wiring". Why can't I include my power wire? Interference? Has anyone else included other wiring? Will I have to run separate conduit?
SteveS
 
Sponsored Links
  #2  
Old 04-29-17, 03:39 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,411
Received 752 Votes on 707 Posts
All the splits I've installed use regular electric wire for the control signal as it's carrying main power from the outside unit to the inside unit. I know of no problem with crosstalk between those cables.

If you want to leave the make and model I'll check for specifics.
 
  #3  
Old 04-29-17, 06:09 PM
S
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 173
Received 0 Votes on 0 Posts
It's a Senville model 12CD.
My signal cable I got from a elec supplier. A nice 4 wire hot cold water resistant thing.
 
  #4  
Old 05-03-17, 07:10 PM
S
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 173
Received 0 Votes on 0 Posts
When I bundle everything together, I'll tape the signal cable on the opposite side of the tubing/drain hose from the 12-2 power wire. Separate them the best that I can.
Better work OK.
 
  #5  
Old 05-03-17, 07:57 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,411
Received 752 Votes on 707 Posts
Pretty stingy with the online technical support.

You should be ok. I've never had any problems from them being too close together.

With the bulk of my split system installs..... the same gauge wire was required between the units that was required for the supply to the outside unit.
 
  #6  
Old 05-05-17, 06:32 PM
S
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 173
Received 0 Votes on 0 Posts
Same gauge wire, eh? Maybe I'll ask the elec inspector when he stops by. Maybe I won't even mention it.
What surprised me was this:
I used 12-2 romex thru my attic, then UF down to the outdoor unit. Regarding the splice - he said I could splice it in the attic. I specifically asked if it had to be accessible, but he said a box in the attic was Ok. As long as it is above the insulation. So that's what I did.
It's at the opposite end of the attic as the access door. And about a foot of blow-in insulation. Like parting the Red Sea.
 
  #7  
Old 05-05-17, 07:02 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,411
Received 752 Votes on 707 Posts
As long as it's accessible in the future....it's ok.
 
  #8  
Old 05-06-17, 04:35 PM
H
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,824
Received 1 Vote on 1 Post
control cable

OEM from Panasonic told me the other day, The Sanyo I was working on requires an 18/2 shielded cable with drain and grounded. I hadn't heard of a drain and some others I spoke to with hadn't either. I have a friend that works in a cable co and he told me the shield has two sides. One is an aluminized mylar/ metallic that surrounds the cable with the metallic side inside along with an uninsulated wire that appears silver in color. This is the drain. It is always in contact with that mylar shield touching the aluminized side and carries any stray voltages or flux lines to ground to prevent signals from interference. This signal is 12VDC. He told me he's had issues with several machines and this shielded drain cable helps... Your not supposed to run two different lines, like high voltage with low voltage, in the same conduit, on the older stuff, unless it had the same insulation like THHN. The new stuff with all the circuitry may be a bit more sensitive especially when its converted to DC as many control lines are.
 
  #9  
Old 05-12-17, 07:39 PM
S
Member
Thread Starter
Join Date: Nov 2004
Location: north dakota
Posts: 173
Received 0 Votes on 0 Posts
Hey PJ,
How long of a run have you made with the tubing? Is 40ft too far?

And, have you ever mounted the condenser on a roof?
My bilevel, the garage roof is about 5 feet below the house roof. BUT, from the garage roof it is just 1 foot thru the wall to an upper bedroom, and about 15ft to another room. And the garage roof is on the north end of the house. It would be in the shade of the house roof.
 
  #10  
Old 05-12-17, 08:14 PM
R
Member
Join Date: Oct 2016
Posts: 1,721
Received 92 Votes on 86 Posts
The unit should list maximum lineset lengths in the manual. Every manufacturer has different limits. It would be easier to mount to a wall then roof. The unit must be securely mounted so it cannot fall over
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: