Asking this question for my brother in law who knows only slightly more about AC than me and that isnt much:

New AC installed but concerned with the wiring.

The equipment ground in house provided by metal conduit (no green or bare conductors in outlet boxes).

New AC is fed by 10/3 on a 30A double pole breaker. Non-metalic UF cable is used and connects in a junction box before entering the panel. So that means there wouldnt be an equipment ground (green or bare) connected in the junction box where it connects with metal conduit.

Is the AC grounded because it is a 240 circuit (grounded conductor) or since the non-metalic doesnt have a 4th wire connected back at the junction box, does this mean the AC unit is ungrounded?

 

The metallic conduit can serve as the ground from the panel to the disconnect near the unit. The ground from the UF should connect to a ground bar in the disconnect.

A/C units are straight 240 volts and only need 2 hots and a ground.

 

Are you sure it's 10-3? Most condensing units use plain 240V and don't need a neutral.

Regardless, Type NM-B cable contains a grounding conductor. That conductor is bonded to the J-box and the chassis of the unit to provide the equipment ground.

 

I think this might be a hack setup, installer said it was OK though?

There is indeed 10/3 with ground UF cable. It connects near the panel in a junction box and extends approx 100' to the outside disconnect.

In the junction box next to the panel the two hots are connected and the white wire passes thru the junction box into the panel. INSIDE THE OUTSIDE DISCONNECT, THE WHITE WIRE IS CONECTED TO THE GREEN WIRE OF THE AC UNIT. The bare ground in the junction box appears to be cut and does not connect to another bare wire nor does it connect to the back of the junction box nor does it connect in the disconnect.

So this means the AC is not grounded then? A dangerous situation right? Or is it grounded thru the white wire? Again the equipment ground (green wire) of the condensor connects to the white wire in the 10/3, that white wire connects in the panel. (I assume to the neutral busbar but I havent opened the panel). Im guess we have an issue here, is that proper grounding? Or are we going to get electrocuted?

 

Definitely a code violation. The cable should be replaced. Preferably with a weatherproof whip such as THWN in SealTite.

 

Please explain further. The fact that the equipment ground is connected with a white wire (guessing back to the neutral bus bar). This is not a subpanel if it makes a difference.

Is this similar to 3 and 4 prong dryer cords? Is my setup grandfathered in that case?

Besides being confusing, is this a safety hazard?

 

By code ground wires smaller than #4 must be factory green or bare. Other color wires can not be redesignated.

No. Dryers are 120/240. Your AC is 240. The dryer uses a combined neutral ground. Your AC has no neutral. Not the same thing and not grandfathered.

Bottom line is the cable should have been 2-conductor. If 3-conductor was used despite not being needed the correct thing was to cap the white and not use.

 

I think that would qualify as a hack job.

It sounds from your description that the A-C unit is grounded, but it's not properly done and as has been stated, it's a code violation.

No, it isn't OK, but it may work. A-C installers typically aren't electricians. Just because it works doesn't mean it's right.

Just curious, why would you need air conditioning in Alaska?

 

Thanks.

I just opened the panel and see the white that is connected to the equipment ground in the disconnect is on the bus bar in the main panel.

MY MAIN CONCERN: Is property or life in danger here?

Short of rewiring. What would you do if this was at your house? I figure I would mark the white wire with green tape and be done with it..... The outside unit is grounded then correct?


BTW: The 10/3 wasnt a new install, it was in place with old equipment. So installer is not at fault in this case. This unit isnt in AK either Joe, its at my brother in laws.

 

If the busbar you are referring to is the grounded neutral bus at the main service panel, it is connected correctly for a ground.

Yes, the outside unit would be grounded. If it was my house, I'd rewire it correctly.

I cannot answer that. It is a code violation and the NEC is all about safety. The unit is grounded, but not properly grounded.

 

SO your saying if this was your equipment, would incure the major cost and undertaking of removing the 10/3 line and then running conduit 100' thru walls and ceilings to get 10/2 wired up?

I understand its a code violation but when you say "not properly grounded" your just refering to color references to the wire correct? Its actually grounded exactly as it would be if a bare or green conductor was used.

So instead of complete re-wiring wouldnt just redesignating the wire with green tape be the most logical fix?

Of course my main reason for posting is the safety concern, so my question stands.... is this dangerous to life or property?

 

I would. But I'm curious about a couple of things. One is, why conduit? The other is, why Type UF originally? If this is all inside, as it sounds like it is, I'd run 10-2/G Type NM (Romex). Cheaper, easier to pull, and easier to make up. I'd use the UF as a pull string if I could, or just find another path.

No. A non-compliant "fix" for a non-compliant installation is not a fix at all. If you want an acceptable alternative to replacing the wiring, you can request an inspection of the existing installation by the local jurisdiction's inspectors. Since it's an installation you (or your BIL) found in place, the fee should be nominal. If the local AHJ blesses it, in writing, then you're good to go.

Keep the piece of paper in a safe place,

 

Nashkat:

THis installation is in Chicago and I think to be compliant would have to be conduit. THe UF was not right to begin with. I dont think romex would be allowed by code at this point either.

Im guessing your an electrician? So perhaps pulling new wire would be cheap and easy for you.... but if you ran into this installation on a service call, would you suggest the homeowner remove and replace everything?

Here your suggesting its a dangerous situation right? As in keep your piece of paper so to give to the insurance company when the house burns. right?

Ray:
The whip between the AC and disconnect is the standard weathertight felxible pipe stuff you see on all AC's. The UF in question is between the panel and the disconnect.


Unfortunetly, nobody wants to touch my main concern with a ten foot pole I see.....

 

More information is often helpful. No, you probably can't get Romex approved in Chicago. But you can get Type MC or AC approved, and you can buy it in every neighborhood hardware store there.

You don't have to guess, you can check my profile.

No, I wouldn't suggest that the homeowner replace the wiring between the panel and the disconnect. I'd insist that he or she do it - or find a different electrician. Besides the fact that it's just non-compliant and potentially hazardous, you've now told us that this is in an all-metal jurisdiction. Leaving that in place with my name on a job ticket would be worth every license I own, or hope to own, not to mention a sizable fine. Cook County is strict.

I couldn't leave it in place the way it is in good conscience anyway. And I'm not suggesting that it's cheap or easy - just that it's necessary.

Yep. The NEC requirements, and Cook County's stricter ones, have been adopted for good reasons. They're all about life safety. The NEC is also NFPA 70 - Section 70 of the more comprehensive fire, electrical and building safety code adopted by the National Fire Protection Association.

Insurers, naturally, have been a driving force behind the adoption and revision of life safety codes. Guess who the underwriters in Underwriters Laboratories are.

That piece of paper might come in handy to have it to show the home inspector at sale time too.

Does it have a green insulated ground wire in it that's bonded to the disconnect box, the house "ground" and the chassis of the condensing unit?

Safety? Read this post again if you still don't think that's been addressed.

 

You can run MC or AC for a 100'?

Like I wrote in the previous post, the equipment ground green wire of the AC is bonded to the disconnect with the white wire that is connected to the neutral bus bar in the panel. Besides the color designation and the size of the conductor as Ray said.... its connected the same way as if that wire was bare or green.

I read your post, I understand better why there are codes in place but you dont specifically state what this situation is a safety hazard, please elaborate ....

Is it protection for the next guy that goes into that disconnect and thinks that a neutral wire? Or is the property going to burn because of this setup? If there is a fault, is the condensor going to be live? If there was a fault, is the breaker not going to trip in this situation?

Be specific, please.

 

Sure, why not?

OK

Thanks but no thanks. Not only can I not do that, I doubt if anyone can. That's not how codes are developed. Pick up a copy of the NEC and look in the front, where the committees, and the members of those committees for that edition, are listed. Those are the folks who reviewed all of the field reports and suggestions that have come up in the last three years and developed the changes that were included in that cycle. They balanced direct needs with many other factors including cost, impact on construction, and coordination with other provisions in both the NEC and all other related codes, for example, and they arrived at a consensus - not unanimity, a consensus. That process has been in place in some form since the NEC was first published, in 1897.

Two other points. First of all, we base our advice on the NEC. The NEC is a model code. It has no force until and unless it is adopted, in whole or in part, by the jurisdiction having authority over the area where the work is being done. In addition, many, if not most, jurisdictions include provisions in their adoption ordinance that change or modify or interpret the model they're adopting. Or they just write their own codes. IOW, all codes is local.

Second, Chicago is a leader in developing municipal codes, especially life safety codes. There's a reason for that. So, as I said earlier, you need to get your answer from the Cook County permit and inspection office. They're the only people who can give you the correct answer.

 

I respect your response both thorough and vague as it is.

However, keep in mind that my intention is to correct this and find out why this is dangerous...

Without your further explanation, you now have two families worried that they have a tinderbox on their hands. Should I have him shut off the breaker to the AC until this can be fixed?? Should he call out an electrician this evening? Is it safe to get some sleep tonight with the breaker on? Would it be a good idea to remove the white wire from the neutral bussbar first and then shut off the breaker and pull the disconnect?

Let me know so my family can rest this evening or have someone out immediately.

Trust me I wont hold you liable.....

 

I doubt they'll be needing the A/C in Chicago anytime soon, so sure, shut the breaker off. Then get someone to replace the cable and hook it up correctly.

Unlikely. It sounds like it is grounded, just not by a compliant method. I regret that you're worried now, after reading the information I posted.

No.

 

Not just me Nashkat1. Try 2 families totally about 8 people.

I forwarded your response to my brother in law who is up in arms now trying to find an electrician to come out this evening.... since the ac is connected to the furnace he fears he is going to loss heat or has a shock or fire hazards. With 2 infant children, he is EXTREMELY worried.....

Money is tight too so he may have to just have an electrician come out tonight to inspect it, insure its grounded and make sure it wont effect the heat all winter with the power off. We most likely will have to shut it down until he can afford the full repair.

 

If this circuit only supplies an outside condensing unit which feeds a coil on a furnace, turning off the power to it shouldn't affect the furnace. But it's better to have a knowledgeable person look at it. A good HVAC technician should be able to do that, and they might be both easier to get and less expensive than an electrician, especially on short notice.

He'll still need an electrician to change the wiring though - unless the HVAC company carries an electrical license. Many do.

 

BIL trying to find someone after hours, would you be doing this after hours if this was your setup?

The first electrician he called though told him that although it technically not right that it is not unsafe and that the situation is not an emergency? That didnt satisfy him though because he is freaked out by Nashkats1 stern warning......


Seriously, how should I advise my brother in law in this case? what is dangerous about this setup that warrants immediate attention?? or is that against forum rules to discuss?

 

That's likely to cost him an arm and a leg, if he can find someone.

What stern warning? That electrician is correct, and that's what we've been saying too. Read through the thread again. It's technically not right and should be corrected, but it's probably not unsafe and the situation is not an emergency.

How long has it been working the way it is?

Turn the breaker off if he wants to. Go to bed. Start gathering three bids tomorrow, after both coffee and breakfast.

No, but it defies common sense to offer a categorical answer on something like this, when we can't see and test it.

 

From reading through the thread I do not see what was done as a safety or fire hazard, but is a technical violation of both the accepted color codes and also the materials used. I would have this corrected, but not tonight. When money allows should be fine.

 

Nashkat1- No offense, but now your sending mixed messages.

Prior to this you said it was potentionally dangerous (without further explanation why) and suggested I get the AHJ's involved so I can have the paperwork ready for the insurance company when the house burns down.

Your replies sure come off like this is an emergency.

 

I feel sad when I hear you say that, but I'm not offended.

I said it was potentially hazardous, but I can see how you could have heard that as "potentially dangerous." Interestingly, I explained why in the same phrase: I then went on, in that post and others, to discuss the life safety focus of electrical codes, and their place in the constellation of life safety oriented building codes.

What I meant by my choice of words was that it might present a hazard to an unsuspecting person. When you suggested some possible scenarios in a follow-up question, I felt that I'd been heard.

Now you're putting words in my mouth. I object. It's unsanitary.

I said that your BIL could get the existing installation inspected by the AHJ if he wanted the real answer because only the local AHJ can provide that answer - anywhere. Part of my thinking was "Hey, it's worth a shot. I've seen inspectors approve things that I never would have dreamed that they would." Besides, he'd have the best possible advice if he did that - and only if he did that. And if they did approve it he could hang onto some of his limited (by your account) money. Since that service is provided by the municipality out of its revenues, the advice will also come at no cost to him.

I advised that he get the approval in writing because others might not trust that he'd actually gotten it without evidence. I also suggested that he keep it in a safe place, so that he would have it to show those doubters.

I didn't suggest that he might need it to show to an insurance investigator. You did, albeit by suggesting that you understood my thinking:I figured that you were engaging in hyperbole, but decided to take it as an opportunity to point out how adopted electrical codes are linked to the insurance industry and to national testing agencies,

I wish that I'd called you on the projection at the time, but I didn't.It might defuse the anxiety iif posit a scenario I thought.

I regret that you chose to interpret them that way.