Fujitsu Ac units

[Jerseydaze]

I am wiring a Fujitsu Split room Ac combination unit the unit has 2 wall units ans one out door unit (condenser) If I am reading the manual right I need three disconnects outside .One on the branch and two fused down to 5 amps for the 14 gage connection between the wall units.Does this sound right anyone done these before i dont remember ever seeing three disconnects like this.Any advise appreciated here is the manual.

http://www.fujitsugeneral.com/PDF_06/InstallationManual/(IM)AOU24-36RML-Inner.pdf

 

[Pullnwire]

I have done quite a few of these, they work great and are very high tech. they have a variable speed compressor and fan coil, very efficient. The first disco is for the main power into the condensor. The second two are are to fuse down the feed to the fans inside to 15 amps. If the unit is small and only has a 15 amp 208 feed, then you only need a 2 pole switch for a disconnect. Be careful, there are a few things that are important. fujitsu requires stranded wire between the condensor and the fan coils. I have used 12-3 stranded mc or #14 thhn in flex. They sell "inverter wire, but it is a buck a foot and all it is is #14 4 coductor speaker wire (300v) that says Fujitsu on it.
Also, be sure to pay attention to the terminal # and colors you land between the units. it will not work if you cross one up.

 

[Chamuit]

Be careful, there are a few things that are important. fujitsu requires stranded wire between the condensor and the fan coils.

Another thing, you cannot have any splices on the stranded wire between the units. We had to go back on a job were the house electrician had pulled the wires through 4 j-boxes and spliced at each one. It didn't like that. We had to re-pull all the wires (~150') through all the j-boxes continuously for two units.:roll:

 

[quogueelectric]

Another thing, you cannot have any splices on the stranded wire between the units. We had to go back on a job were the house electrician had pulled the wires through 4 j-boxes and spliced at each one. It didn't like that. We had to re-pull all the wires (~150') through all the j-boxes continuously for two units.:roll:

I am sorry but I find the no splices hard to believe there is no reason I can see to support this statement.

 

[Pullnwire]

I am sorry but I find the no splices hard to believe there is no reason I can see to support this statement.

all I know is it dont work if you even look at the wires funny. the blk and white are power and the red is a comm line to the drive. some black majic voodoo stuff.

 

[Chamuit]

I am sorry but I find the no splices hard to believe there is no reason I can see to support this statement.

That's what we were told by the install supervisor which was the explanation from the factory as to why the units were not working.

 

[Pierre C Belarge]

What about the disconnect for the inside unit mounted on the wall?

 

[quogueelectric]

That's what we were told by the install supervisor which was the explanation from the factory as to why the units were not working.

I have read the pdf manuals for these units they are verry impressive. I cant wait to wire one I see them all over the place and I hear they are verry efficient.

 

[Chamuit]

What about the disconnect for the inside unit mounted on the wall?

Ya got me! We did have a DPST switch . . .

 

[quogueelectric]

Ya got me! We did have a DPST switch . . .

Couldnt you just cord and plug it flushmount??

 

[Chamuit]

Couldnt you just cord and plug it flushmount??

This was a pre-existing condition. Our only job was to re-pull the wire continuously from point A to point B. I would imagine that a cord and plug would work. Come to think of it, this is an auto detailing place. The fewer soft cords laying around, the better.

Edit - There were signal wires too. So, a C n P wouldn't work.

 

[Jerseydaze]

any great design ideas is for a finished home

 

[Pierre C Belarge]

the inside units are not cord and plug connected, as far as the ones I have seen. They are supplied from the outside condensor. The line voltage units require a disconnecting means...usually a switch of some sort.

There are some units that are coming low voltage for the inside unit. These are either of 16v, 24v, 32v. The installation instructions with those show they do not require a disconnecting means.