Replacement Breakers - Do They Violate NEC, Warranty and or UL listing? (12/30/99)

UL Articles

Mike, an established manufacturer of electrical panels has a label stating that "The use of other than our own breakers voids all warranties and may result in damage or electrocution", However, another reputable manufacturer sells replacement or after-market breakers which fit the competitors box. Would there be a reason to tell a homeowner that his system has been tampered with and the integrity of the warranty was violated?



NEC 110-3(b) prohibits the use of equipment where labeling strictly disallow the use of those components.

From: Gary Green, iceman

Yes!! This is a code violation. Section 380-3(a) states "Switches and circuit breakers shall be of the externally operable type mounted in an enclosure listed for the intended use. ...." Even though the other manufacturer may make a breaker they claim will fit into this box, the panel does not list this device for the use there in.

From: John Hall

The manufacture has his panel and CB tested for his panel only, and it's a code violations to use any other type of CB for that panel. Manufacture of CB can make other brand names breaker for other panel if the manufacture has the CB listed and tested for the panel and then the package of the CB must state which panel the CB can be used in or which type of CB it can replace. Also, see Section 110-3(b) to follow manufacture instructions.

From: John Landry

From what I understand, UL only approved the boxes to be used with the manufacturers breakers only. Its like when wirenut were being squirted with de-ox for Cu to Al applications. The wire nut companies said "Hold up, our wirenut's are not approved for this application" so they came out with a wirenut that was UL listed and instead of 8 cents apiece they now cost you $1 a piece, but they are UL listed. Keep in mind that it cost between 4000 and 8000 dollars to obtain a UL label. It's just another way for the manufactures to make money. That what I think.

From: Mike Wood

No, in fact, only if a problem is caused by the replacement breaker (and the manufacturer must be able to prove it) is the warranty voided, despite what the manufacturers might want you to believe. The posting of such a notice is a violation of the Clayton and Sherman Anti-Trust acts (and probably also Wright-Pattman because it "ties" the subsequent purchase to the original purchase through warranties. If you were to tell the homeowner that the system was no longer warranted, you are misinforming the customer. If you subsequently sell him a system based on this misinformation, you are getting pretty close to outright fraud. IBM lost a case, which was similar in some respects and I wouldn't try such a tactic unless I had better lawyers and more money than IBM.

From: morcre

The only warranty that would be in effect on the breaker replacement will be the one that your company holds for its prescribed warranty period. Most manufacturer's recommend their replacement parts over other's simply as a sales tacit. Your homeowner should be aware of the current warranties; but I would say that "tampering with existing" is more than likely already been voided if the work previously done is already in excess of one year; which is most standard company warranties expiration terms.


Article 110-3(b) of the NEC states that Listed or labeled equipment shall be used or installed in accordance with any instructions included in the listing or labeling. Just because a breaker fits in the panel does not mean that it is okay to install it in that panel. To my knowledge, only one manufacturer has had their breakers tested and listed to install in other manufacturers panels. However, even that breaker is not allowed in a panel that is specifically labeled against installing other brands of breakers. Some panels even limit the use of certain series of their own breakers in their panels.

As to whether to tell a customer about the violation of their warranty, I can only offer my opinion, I have not found any code article that requires it. When I have been called out on a service call and I examine a piece of electrical equipment, I feel that the customer is expecting me to give an honest evaluation of the condition of that equipment. This would include corrosion damage, heat damage, loose or improper connections, and any other thing that might affect the performance of the equipment. In my opinion that would include the condition of the manufacturers liability due to a modified system. In informing the customer, I am not required to insist that they correct the problem, but in doing so in writing I have relieved my employer of all liability should a problem occur.

From: Neeser, Dan

Mike, This is true to what I was told when I worked with C-H/Westinghouse. This was a big issue of concern for them. Unless the breaker is serviced/reconditioned by the manufactured with all the manufacturing specs required, the warranty is voided. I'm sure this is the status quo for all manufacturers.

From: Pat Hansen

My personal feeling is this: If the replacement breaker states that it has been listed or labeled for the use in the existing panel I would say that it would supercede the original listing of the panel. Reasoning: Manufacture "A" never intended for anything to ever go wrong with their equipment, and planned on being in business for a long time. Well as fate would have it they were not around as long as the had hoped. So for the ease of replacement, to save on the cost of a complete service replacement Manufacture "B" has come up with a listed replacement breaker for Manufacture "A" 's Equipment. As long as the replacement breaker complies with 110-3 (b), I don't believe that this is a problem.


If a product is labeled as you state, then should "something" happen, and go to court, I am sure the manufacturer would be absolved. How would a manufacturer know how his product would work when some other manufacturer's product was installed in his panel?

What do you think GM would do if a mechanic installed a "Brand X" carburetor on a GM car...and the car blew up due to gasoline leaking out of the Brand X carburetor?

From: Scheidecker, Brad

Mike, This is an opinion only...I would definitely inform the homeowner of the nameplate and possible loss of their warranty. It is the homeowners "call" on whether or not an after market breaker should be installed.

From: Stauffer

Dear Mike: UL tests and rates circuit breakers by one manufacture (such as Murray) for use in other manufacturers' panelboards (such as Square D). I believe this is called "classification."

The bigger, more reputable manufacturers hate this practice and always have, but UL does it nevertheless. Therefore, I believe the panelboard manufacturer's warning label is merely a scare tactic, and that anyone can install a properly classified breaker in another brand of panel.

Of course, there probably are breakers that are mechanically compatible with other brands of panel but that have not been classified for use in them. (Classification, like listing, costs money.) This is a grayer area for which I have no good, short answer. I guess a careful, liability-minded electrician or contractor would check his UL listing directories before installing a Brand "A" breaker in a Brand "B" panel.

BROOKE STAUFFER, Director, NECA Codes and Standards


Mike: Seems you had a wide variety of comments. Most seemed to indicate that the practice of installing something that the panelboard manufacturers label clearly prohibits would be putting yourself way out on the limb.

Square D's position is simple. Our panelboards are clearly marked with what circuit breakers are permitted to be installed. Installation of anything contrary to that marking will void our warranty and we will certainly make that point loud and clear should something go wrong with the installation. This is not only based on our listing, but also takes into account the 40+ years of design and application expertise our engineers put into the circuit breaker/panelboard combination.

I have seen many comments that indicate that this is only a "scare tactic," etc. However, keep in mind that the product standards have, for many, many years, required that the panelboard be marked with the circuit breakers that are permitted to be installed, and for good reason. When manufacturer "A" says that their breaker can be installed in manufacturer "B" catalog XX-XXXX panelboard, I wonder which version of that panel they were talking about. The version made in 1998, 1993, 1989, 1985, 1980, etc? Keep in mind that the catalog number might be the same, but the design changed many times. This is where the panelboard manufacturer spends a great deal of time, making sure that things are compatible. Manufacturer "A" would have no idea what the "history" of that product was through all those years.

The vast majority of electrical inspectors (and electrical contractors) will tell you that they go by what is marked on the panel. Do anything else, has too many variables.

Jim Pauley, P.E.
Square D Company