need to downgrade breaker (from 40amp to 15amp) for new hvac?

Hello, I recently had a home inspection in preparation for selling my house. The inspector informed the buyer that I need to downgrade the circuit breaker (from 40amp to 15amp) for new hvac? He said he sees this problem a lot. My father, who does a lot of DIY including some electrical, says that if we change to 15amp when the hvac switches to aux. heat it will blow the breaker?

I need to find out if this really needs to be changed, the inspector warned the hvac unit could be damaged if this isn't changed. But I don't want to have the change done if it will cause problems when the unit goes to aux heat.

I'd call the hvac installer, but, clearly, they didn't think it was necessary to change the breaker & I'd really like an independent opinion on this.

ALSO, is changing a breaker best left to an electrician or might this be something we could do ourselves?

Thanks in advance for any input. WJ

Reply to
walknonsunshn
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If the unit has an electric heating element in it that requires a 40 amp feeder, you don't want to change it. It may be possible that two feeds are required, one for the blower and a separate one for the heater and your father installed an improper jumper to feed both. I would call a local electrician to give a look

Reply to
RBM

Maybe the inspector is talking about the size of the conducter on the breaker? If it's #8, it is correct for the 40A breaker. If it's smaller, the breaker needs to be changed appropriately.

Bill

Reply to
bill allemann

I have a feeling the inspector doesn't have a clue, but...

Is this a new HVAC installation? Is this an existing breaker w/ a new unit or a new installation for it? Either way, if the unit has been recently installed, I'd first just check w/ the installers and find out what they say before anything else. If it is a new installation, you may well have some information for the unit that describes the required service feed(s) -- check for that.

As someone else noted, if the service feed to the unit is sized properly for the existing wiring, it's unlikely the breaker needs to be changed. The point of breakers in distribution panels is to protect the wiring, _not_ the device. The unit itself will be protected by internal fusing or breakers or a combination of both. Thinking a breaker must match a nameplate load rating for "protection" of the load device is a common misconception I've found more than one inspector to have (hence my first comment).

If you don't get a satisfactory response from the HVAC guys or from what you can learn from the information left w/ the unit (again, assuming it's new), then if you don't have sufficient expertise to determine for sure it's time to ask an electrician out to check. I'd think it unlikely to need that much, but you may have to go that route if the inspection report has actually gone to the potential buyer to have sufficient pedigree to satisfy...

Methinks this will turn out to be a tempest in a teapot...

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Reply to
dpb

Thank you for your responses.

We didn't do any of the wiring ourselves, the breaker is the same from the prior HVAC unit (ca. 1987), I'm fairly certain the contractor who installed the hvac a few months ago didn't make any change to the breaker(s). He seemed quite competent and earnest, so I'm a little reluctant to accept the inspector's word as gospel. Either way, I'm concerned about a liability situation down the road, so I'm trying to research this prior to having someone in to make a change.

The inspector stood in front of the breaker box pointing to the 40amp breaker when he made the statement, so I'm pretty certain he's referring to the breaker. The buyer read aloud a liability disclaimer based upon the inspector's report.

I read all of the literature that came with the unit - an electric heat pump/air conditioning unit w/air handler.

I did find this within the paperwork for the new unit (not sure if this is relative):

This unit is designed for single-phase electrical supply. DO NOT OPERATE ON A THREE-PHASE POWER SUPPLY. Measure the power supply to the unit. The supply voltage must be in agreement with the unit nameplate power requirements and within the range shown in: Nominal Input 208/240 Minimum Voltage 187 Maximum Voltage 253

I don't mind saying this is pretty much greek to me, but does this mean if I check the plate on the unit I'll be able to tell what kind of breaker is best (based upon the range info above)?

I plan on having someone come in to make the change, if it's necessary, but I'd like to have an idea of whether it needs to be done before 'going there.'

Again, thank you so much for any input.

WJ

Reply to
walknonsunshn

Yes, but what Bill Allerman posted is important as well. The feeder cable must be sized for a 40 amp breaker, which would be at least #8. Look on the unit's name plate for an amperage rating or even a recommended circuit breaker size. The full load amperage will determine the size wire and breaker required

Reply to
RBM

Thank you for your reply dpb, I missed it when I posted a few minutes ago, I lost a post somewhere, so if this one is a duplicate, my apologies.

See, I think you could be right about the inspector. I'm sure he's quite knowledgable, but if he's seen this problem often, I figure hvac units are installed by certified hvac techs.. who would be more likely to be the expert? Additionally, the lack of any liability for his findings/report makes me hesitate to take his word as gospel... if he's wrong & there's a problem w/the unit after we switch to 15amp, who is liable? maybe me? I may end up telling the buyers if they want me to have it changed, I'll have it changed, but I've let them know I'm not certain it should be done. I'd contact the manufacturer, but I'm afraid of voiding the warranty.

This is a new unit, installed a few months ago, installer seemed quite competent and knowledgable.

Reply to
walknonsunshn

Unfortunately, in my experience in many cases it is the inspector. Many "certified" HVAC techs take shortcuts if they can get away with it. After the #1 shortcut (inadequate evacuation prior to system charging), failing to downsize a breaker when installing a more efficient system is probably the #2 shortcut taken. Having said this a reduction is breaker size from 40A to

15A seems a bit extreme unless there was a significant change in the system (for example, the elimination of resistive heat strips in the air handler).

See comment above. Did the installation require a permit in your municipality? Was one pulled? Did the installation pass the municipality's final inspection? If no permit was pulled and one is required, the HVAC installer was probably a hack.

Finally, are we talking about the breaker for the air handler or the condenser? Does the air handler have heat strips (aka emergency heat)? What is the make and model of the air handler and condenser, and what are the specifications for the electrical supply for each (note: should be on manufacturer's nameplate)?

Reply to
Travis Jordan

First time posting so this is a test.

Reply to
mike

Nope, not on an HVAC condenser. Read the label on the condenser and size the breaker/wire accordingly You should see miminum circuit ampacity, that is the wire size based on 301.16 (not 240.4(D) so 12ga is good for 25a, 14ga 20a. Then look at maximum branch circuit over protection size and that is the breaker you can use. It will NOT be what you would think. This is for short circuit protection, not overload protection, that is internal in the compressor as a general rule. You can very well see a 40a breaker on 14 ga wire.

All that said you still have to wire and protect the heater strips in the air handler like a regular circuit, using the 310.16 rating on the wire. Again that will be in the installation instructions as to what wire and breaker combo you need for each heater option size.

Reply to
gfretwell

I don't believe it's on a condenser. I think it's an air handler with heating strips

Reply to
RBM

I would as why?

Gauge of wire too small, per maker's instructions, etc. Oh, are you sure you got this right, did you get it on paper or overhead a conversation. I'm guessing a communication error first. ;)

tom @

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Reply to
Just Joshin

What I have seen done a lot is for the breaker in the main panel to NOT be changed when a new unit is installed but the correct sized breaker to be installed in the disconnect box located next to the unit. Assuming the wire from the breaker to the disconnect box is properly sized this would be fine. Not something the average home inspector is smart enough to realize.

The final protection for the unit is at the disconnect box. The wiring may be able to carry 40 amps to the disconnect but if that is a 20 amp breaker only 20 can pass to the unit.

By doing it this way the HVAC contractor has not messed with your wiring or your breaker box and is only liable for the disconnect and the unit. It is a CYA (his A) type of thing.

If that is the case a simple letter from the HVAC contractor should be enough to satisfy the "repair requirements" of the home inspection. You should offer to pay the HVAC for the time to write the letter. Most will not charge.

I have never seen a home inspector argue with a licensed person who is willing to commit something to writing.

Colbyt

Reply to
Colbyt

What, precisely, is the "shortcut"? If the existing wiring is sized for

40A, the circuit breaker isn't intended to do anything but protect the wiring from short circuit faults, _NOT_ the load device, whatever it is.

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Reply to
dpb

snipped-for-privacy@aol.com wrote: ..

I'm not that confident in his expertise... :) In fact, I'm giving pretty low odds that he is right on this and, conversely, the other way 'round that he has the misconception of the breaker supposedly protecting the device...I fully expect that the vendor requirement will be for a _minimum_ of some value and as long as the original circuit wasn't miswired the larger breaker is perfectly find for its intended purpose.

The worst that can happen is the unit will trip so guess you could just leave them w/ the problem. My understanding of the disclosure rules is you make a disclosure of existing conditions, it's up to the buyer to agree/reject/negotiate.

No how, no way can simply asking a question affect the warranty.

And I'd wager they probably were/are. If you haven't, I'd check w/ them and get an explanation of their understanding of the inspector's concern. If it makes sense (as I suspect it will) I'd give it to the buyer and go on. If not, then you can decide whether an independent opinion is worth the $$ or not.

OBTW, changing a breaker is pretty simple. Of course, be sure to turn the feeder breaker off...

Reply to
dpb

Then change the breaker and add into the purchase agreement a disclaimer for the inadequate breaker and lay hte blame on future breaker trips on the incompetent inspector. Include power requirements (amp draw) of the HVAC unit. Your attorney should know how to word it and lay the blame and liability squarely upon the inspector's report. Be absolutely certain to include the SIGNED (the inspector and buyer's signatures) inspection report in the closing of the house. Have fun finding a 15 amp 240 breaker! 20 is about the smallest I have seen and if you do find one, the wires might be too big to fit them into the breaker! All you need to do to replace it is to shut if off, take off the breaker box cover, unscrew the wires, pull out the breaker, put the new one in, connect the wires, replace the cover, and turn it back on. Simple job!

I can guarantee that it draws MUCH more than 15 amps unless it is a micro .25 ton unit! My 2 ton requires a 25 amp breaker and it also needs the furnace! An electric heat pump plus aux heat requires even more amperage!

Reply to
Mike Dobony

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It is a violation of code to put a 20a breaker on 14ga wire! 12ga is required!!!!!!!

Reply to
Mike Dobony

Travis J beat me to the puch on the question: Is this breaker for the outside condensing unit, or for the inside air handler? Very few condensing units call for a 15amp breaker. I have only seen a couple--certain brands of 1.5 and possibly 2 ton units. Regardless, the unit will have a maximum breaker size on the data plate, and some brands list a minimum as well. Go with whatever it says, making sure the wire is large enough. Larger wire than necessary is fine. If it is the air handler you are referring to, even the smallest heat strips made will require a lot more than 15 amps. The problem is that the airhandlers are usually ordered without heat strips, and they are ordered separately and installed when the unit is installed. You have to first know what size heat strips you have ---they can be from 3KW to 20 KW. They are sized according to the amount of heat desired, and the available power. Call the installer and get all the info from them. They may be willing to talk to the inspector and get this resolved over the phone. Our service mgr gets involved with things like this from time to time. Good luck Larry

Reply to
lp13-30

The circuit breaker is there to protect the load device and the wiring. The shortcut is that some installers don't downsize the breaker when installing a more efficient system. The NEC, most state building codes require appropriate sizing. Most HVAC manufacturers specify the maximum fuse size (MFS) and maximum circuit breaker size (MCB) for protection of their equipment. Of course the wire size has to be large enough for the intended load.

Generally the calculation is: MCB = 2.25 x largest motor amps (FLA or RLA) + the sum of the remaining motor amps.

Reply to
Travis Jordan

For motors the rules change. The breaker protects the wire from short circuits, not overloads, as gfretwell said. Rather arcane rules for motors are among the reasons why electricians have licenses.

It is not possible to give an answer to the OP's question without nameplate information for the equipment connected and wire size. I wouldn't necessarily trust a home inspector apply the rules. I also wouldn't necessarily trust an installer to do the electrical right - particularly if the electrical was not done by an electrician.

-- bud--

Reply to
Bud--

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