So we just replaced our a/c unit with a new one. Our HVAC guy has all of the plumbing taken care of but doesn't do the wiring. It just seems like a shame to have our electrician come all the way out for just five wires. It'll probably cost more to make the trip out than it will for the labor. The power wires are a no-brainer, but there are two blue wires coming from the unit, and a white and a red coming from the house, that I'm not exactly sure of. Is this something a fairly handy guy can handle, or am I treading in a professional's-only domain?

I think it depends on what is there already.

Seems I recall being told that there must be a disconnect switch put by the unit, and there must also be a 120V receptacle installed to facilitate power supply if needed for servicing, etc.

Don't know if all that is true, but it sticks in my head for some reason.

The HVAC guy cannot by law do the electrical unless he holds an electrical licsense.

Kind of funny how you say "The power wires are a no-brainer, but there are two blue wires coming from the unit, and a white and a red coming from the house, that I'm not exactly sure of."

Not really a no brainer, huh? Spend the $100 bucks and get it done right.

Not to be a smart a@@ but I've seen to much of my trade given away here. Some things are best left to those that are in the know.

Awww, come on.....give out the info. It's not like there are people stealing your work.

I see your point, but it's a service call, nothing more.

the two blue wires are the low voltage wires.
just hook them up to the two low voltage wires coming out of the house.
You do need a disconnect on the side if the house.
The line voltage should be on 24 hr. before you start the unit.
There is know way you can know if the unit has the correct charge if the unit
is not running.
The contractor should have told you the line voltage was not included.......
Id be looking for a different A/C man if I were you.

GOOD LUCK

Thanks, fastkaw. In response to the idea of giving away "trade secrets", I completely understand where you're coming from, mnfishingguy. Having been in the boat repair business for over 20 years, it's difficult for me to give away free help and advise on the boats and motors forum. But, that's the whole purpose of these forums is to help and share information with fellow sportsmen. I've found that do-it-yourelfer's are going to tackle projects regardless of how much or how little professional advise that they get. I'd rather help these guys out so that they can have the satisfaction of getting their project done successfully. What I've found though, since I started moderating the forum is that our business has actually grown as a result because we're the first one these guys call and bring work to when they do have a project that's too much for them to handle. I would bet that Lawnmowerman and Powerstroke can attest to this as well. I'm not saying that I'm right and others are wrong, it's just my opinion and I thought that I'd throw it out there.

Also, as I mentioned before, I think you need a GFI receptacle in (or within a certain distance of) that A/C disconnect switch. So, that will mean installing a separate 120 circuit from your service panel to power the receptacle.

I'm having a hard time finding a reference/confirmation of that because I don't have NEC code book. But, I'm almost positive that's what the electrician said when he hooked up a friend's new AC system.

EDIT: Just thinking, maybe the stuff I mentioned is only required in a new installation, and not in a replacement?

This is DIY forum not to mention this whole site is based on sharing information. If you want to keep trades secrets, or fishing information to yourself thats up to you. Thankfully there are those that share, without that we might as well turn the lights off.

They make a out door disconnect with a duplex built in. Works pretty slick.
unknown if is GFI or not.
You do need to run a separate 110v wire to it so I don't see any resin why
you couldn't make it GFI if needed.

I have know idea what your cods are in your state/county. In my county you need
a disconnect and that all.

All central A/C units need a out door disconnect..................
Regardless if the code says you need one or not. That my code..........
If you don't have one when I get there you will by the time I levee.
OR IM NOT TOCHEN IT.

Frank, I agree 100% with you but there is a difference between sharing information and telling people how to do it. You know, the difference (in this case) of "those are the low voltage stat wires" and "this wire to point A, this wire to point B,..." when by doing that I either am taking work away from myself or others in the trade.

I know that nobody is going to agree with me on this but that's how I feel. I'll help out a guy all I can but I can't see doing it to the point of taking food off the table any more. Work is getting pretty tight out there. Kind of like the difference between someone saying "15ft in the rock/sand transition" or giving out GPS coordinates.

I dont know if they need a 110v outside, Seems I always have to run an extension cord if I need power while servicing the outside unit.
Some techs are qualified to connect the wires to the unit, and some just refuse to do it.
As far as free trade secrets. I didnt know there were any "trade secrets". If you are afraid of loosing business by advising a DIYer, then advise them to hire a pro before they get hurt or do damage. I was taught to be a professional and make my customers happy and they will bring more business if I treat them fair and resonably. Sounds like most here are smart enough to do that.

I do agree with mnfishinguy, but it will never change. No offense, but people in general are very cheap, especially when it comes to easy labor jobs that they can possibly do themselves.

As for what I do, I figure, let them do it. Chances are after doing it once or twice, they will find out it's not as easy as they thought. Have had to help out DIY'ers before when it started raining on them and their "friends" didn't show up. We normally make sure they are paying a little more also.

I think the receptacle is a somewhat newer (a couple Code revs ago??) requirement.

thanks for that post surface tension! i was gonna say something
but i am not a regular type poster. if you check the poster in question, seems to me he was asking someone a question about
moving a A/C unit away from the house.. hmmm maybe wants a A/C
guy to give away trade secrets?
i am a RV tech and i try to answer every question that is asked
here. its all about trying to help your fellow sportsman.
sorry if i stepped over the FM line..

randy

Nope, not looking for trade secrets, just looking to see if it was possible since I have never seen it done before. When it comes time to do it I'll hire it out, to another tradesman, and if you noticed on my question I didn't ask for anything specific, only if it could be done. I didn't ask for line size needed or if anything out of the ordinary would be needed, only if it was possible.

FYI, I have answered many, many questions but there is a difference in answering it and telling someone how to do it. There are lots of recources out there on how to do things, once you know what you have to do.

How come if someone where to ask where to fish on Mille Lacs the professional guides (who make their living off of what they know) won't give out there honey hole coordinates and the right technique for the time/day and thats acceptable but if I or someone else in the trades (who also makes their living off of what they know) decides not to give out the secrets and knowledge from years of experience anymore that's not acceptable? Doesen't seem fair to me.

This post got way off track and it's my fault and I apoligize for that.

Roofer brings up a great point, it's almost always more expensive to have someone come in and fix anothers mistakes than to have just hired it out in the first place. Again, I'll help out in any way I can, short of giving my work away.