stupid but important question

On the hookup of the air handler to subpanel:

Is it two hots and a ground or

two hots and a neutral.


also on a metal flex can a neutral be a bare ground wire,



I know yall going to fry me on this , thats why it is a stupid question, I just need to be sure, having a brain fart with all these little details.

 

Depending on the rating of the air handler. If it is rated at 240V, then generally it is 2 hots and a ground.
Other than the conductors feeding from the utility transformer to your meter, the neutral may never be a bare ground wire.

 

Brown bag you scare me..........


I enjoy helping homeowners with there electric problems but to think some unsuspecting homeowner is paying you to do electric work in there house is scary.......

 

Mike, I think you may be making a few unsupported assumptions.

 

mike, I,m the homeowner. i do not do this for a living, I work for a civil engineer in foundations. This is my house


but I also did the framing, concrete, roofing, plumbing, Hvac, painting, sheetrock, rough in. just so many detail you forget some, question pop into mind. I just want to make sure before I screwed up something, Also my inspector is someone brother in law, he is really uneducated. The inspector dept here only cares about fees and returned visit not doing it right. I,m about a week away from all finals so I,m double checking everything asking questions.

I was just confused about the netrual on this air handler because there is not one. I was wondering if they designed the bare ground as the neutral and that scare me so I started asking "stupid" question.

All the air handler I have saw had a 120 v, low voltage transformer. So I,m wondering if I need to run a neutral through the flex even if not needed. This is really not compicated to me, just that one air handler.

 

If you have components in that air handler that uses only 120 volts then you must use an insulated white neutral conductor and must not use a bare wire for anything other than bonding the metal case of the appliance to the grounding system. Never are you supposed to carry current on a bare wire. If 120 volt components are in the air handler then you have to have a current carrying conductor [insulated neutral] to carry the unbalanced load that 120 volt component creates back to the panel.

Most air handlers have a transformer in them for low voltage. If you have a control circuit with a transfomer in that air handler than you most likely have a black and white wire coming from that control transformer that is 120 volt component.

If your control transformer has a black and red wire then most likely you have a 220 volt transformer that does not need that neutral.

Most air handlers for a heat pump system only use 220 volt components and no white neutral would be required. However some do use 120 volt components. Those that have 120 volt components inside that air handler will required ain insulated white wire.

HOpe this helps

Wg

 

I went and look again, It has a 240 low voltage transformer. I was just concern about no neutral that why I started asking questions.

 

The air handlers if with no 120 volt components would need not neutral conductor just two hots and an equipment grounding conductor. Much like a outside a/c unit all 220 volt components needs no white neutral conductor.

Good Luck

Wg

 

Brownbag I sorted all your posts on the forums and I owe you an appology.....

Your questions taken over several months seemed like you were contracting out your services but looking at them all at one time I can see your doing your own place.

 

Since I am in sales for this type of equipment I consider myself somewhat of an expert. My experience has been that it could be 120v or 240. some units are 240v because there is an option for electric resistance heaters. Ususally if you do not have an option for heaters it will be 120v. Also there should be a wiring diagram on one of the access panels and that should tell the entire story. Do you have a model and serial number I could probably tell by that. Let me know