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

 

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.

 

It's a Senville model 12CD.
My signal cable I got from a elec supplier. A nice 4 wire hot cold water resistant thing.

 

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.

 

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.

 

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.

 

As long as it's accessible in the future....it's ok.

 

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.

 

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.

 

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