Ham Radio Trips Circuit Breakers

Arc-fault circuit breakers are a boon for household electrical safety. The garden-variety home electrical fire is usually started by the heat coming from a faulty wire arcing over. But as any radio enthusiast knows, sparks also give off broadband radio noise. Arc-fault circuit interrupters (AFCI) are special circuit breakers that listen for this noise in the power line and trip when they hear it. The problem is that they can be so sensitive that they cut out needlessly. Check out the amusing video below the break.

Our friend [Martin] moved into a new house, and discovered that he could flip the breakers by transmitting on the 20-meter band. “All the lights in the place went out and my rig switched over to battery. I thought it was strange as I was certainly drawing less than 20 A. I reset the breakers and keyed up again. I reset the breakers again and did a [expletive] Google search.”

And of course, it’s a known problem in the Ham community. In particular, one manufacturer has had serious problems misinterpreting intentional radiation, and went to the amateur radio community for help to prototype a new version. [Martin] got sent complimentary Ham-resistent breakers when he called the manufacturer and let them know, so all’s well that ends well.

66 thoughts on “Ham Radio Trips Circuit Breakers

    1. Good lord yes to both.

      I discovered the vacuum issue when my shop vac constantly tripped by basement workshop (spare bedroom) and had me pulling my hair out until I learned this. This will be a big issue in Canada soon as the new code will be ALL breakers arc fault (except a sump breaker).

      The bottom plug on my kitchen island won’t accept a plug not matter how hard I ram er in.

      The radio thing happened to me at work dealing with fire alarm panels. When the fire marshal was standing at the panel relaying the info to the field guys when he held the send key down the alarms stopped ringing and after a few radio calls the panel restarted and silenced all the alarms. Needless to say, they freaked out.

    2. “Can’t run an AC in the bedroom” too. Half the summer I couldn’t figure out why my portable AC sounded like it had been kicked every time the compressor would come on. Just happened to look in the breaker panel one day and noticed one of these things is not like the others. It never tripped the breaker, but a UPS on the same circuit would switch to battery for a second and my lamp would flicker. 12AWG extension cord to the hallway fixed it right up.

  1. Are these breakers a US only thing? I’ve never come across anything like this in a domestic setting in the UK. I’m pretty sure that there’s no mention of anything like AFCIs in the 17th Edition (BS7671, UK wiring regs).

    1. AFCI’s have been code in Canada in all new construction (in bedrooms) since 2009. 2018 there is talk of making them mandatory on ALL residential circuits.

      They were put into bedrooms as insurance companies say most house fires are started because of dusty bedclothes against a plug behind the mattress.

    1. All breakers are (and have been for decades) what’s called “trip-free”.

      Even if you hold or lock them into the on position, they can trip internally without the handle needing to move. That’s part of why you need to switch them all the way to off before resetting a tripped breaker.

      We put breaker locks on things like sump pumps, fire alarm panels, and other critical stuff that you wouldn’t want to accidentally switch off when trying to turn a different circuit off.

      1. Limited value in actual implementation: it doesn’t always work.
        Watched a homeowner demonstrate how a breaker to a dryer “kept blowing”. He showed how if reset it would immediately trip. So to demonstrate further, he held it on while it burnt 2 inches of insulation off the wire before frying the breaker and it failed internally, with a hole melted in the breaker shell and the wire end slightly melted. Not a nice smell. Replaced the breaker, re-positioning breakers within the panel due to the now shortened wire, and the circuit and dryer had no fault.

        1. I already encountered a breaker which became too sensitive. A dishwasher circuit, 230V/16A started to routinely trip some time after starting the washing cycle. The electric meter showed the washer using around 3,3kW during heating. Reconnection of the washer to the other 16A circuit (which supplied the rest of the apartment) temporarily solved the problem – clearly the breaker has aged and his thermal switch threshold has drifted low. Then we replaced he breaker as a permanent repair.

      2. For most mechanical over-current circuit breakers mechanically blocking the handle has measurable effect of reducing the sensitivity (the internal design is such that it should not matter, but because of manufacturing tolerances it usually does).

      1. Never mind, missed in the video that he’s transmitting on GMRS frequencies. Wonder why the text says 20m?

        FYI, if that’s a standard UV-82, that radio isn’t type approved for GMRS transmission. Perhaps this is why.

          1. gmrs is in the 462 to 467 band not 2m and the arc fault can be tripped by hf as well as many electric motors
            this was another requirement if the international code who has no consumers, industry, engineers or tradespeople on the board its composed 100% of government building code people and was bullied to add sprinklers for single family homes several yrs ago by a gov fire chief who suddenly showed up with votes soon we will have 100% safe efficient homes that no one will be able to afford to live in

    1. Not real bad, There is a reason that all your electronics talk about type 15 acceptance of RF interference. Lots of things kick out enough RF to cause problems. When I was programming my new Yeasu, I had it hooked up to a mag mount in my living room. On low power (5ish watts) it was enough to cause serious hum in my speakers and cycle the touch dimmer switch across the room. This was at 147mhz. I could do the same thing on 440mhz simplex.

  2. AFCIs are not really known/used outside the US… this is due some strang (to us Rest-of-world-ppl) installation habit :)

    Ham radio equiptment does radiate quite some power… at this close distance even the 20V/m(!) test-levels (DC AFCI… AC AFCI should be identical in that respect) is much to little RF power…

    So it’s just an EMC problem…

  3. The national electric code (NEC) is basically written by insurance underwriters and lawyers. Manufacturers have lobbyists that argue for a code change, (if you can get a new product listed as required equipment =$$$). AFCI breakers are intended to prevent fires by using electronics to detect a spark or wiring problem that could lead to a fire. We all know when you flip on a light switch slowly, you can hear the arc inside the switch, as the two contacts become close enough for the electricity to jump through the air. I’ve tried to trip an AFCI (arc-fault circuit interrupter) breaker by using this technique, but it doesn’t seem to work. When I leave the jobsite, and the home owner flips on the light normally, then it trips.

    Regular breakers are $5, AFCI breakers are $45-$55. Present day electrical code calls for most lighting and receptacle circuits to be on AFCI breakers. 2017 NEC will be even more strict.

    Will the insurance companies save money by these preventing house fires? Will the savings be passed onto the homeowner that is forced to invest in the breakers? Are most home electrical fires caused by professional electrical installations, or “father-inlaw electric service”?

    We’ve been putting AFCIs in for decades, and they are a NUISANCE.

        1. I’m 31 and never actually have.

          Infact, I think there’s something in law about most plugs being sealed units now so you can’t do exactly this (You CAN take the plug off, and put a new one on but you can’t unwire the existing one).

          1. I thought he meant the house outlets.

            But yeah, I think opening up a device and replacing the whole cord sometimes removes the UL approval. Besides voiding the warranty.
            But, most dishwashers, garbage disposals, ceiling fans, electric radiators, large microwave ovens, are hard-wired.

        2. That used to be the way it was.
          Our plug (BS 1363) wasn’t the only “standard” at one point, (there used to be one with round pins) so shipping small appliances, (kitchen gadgets, Irons hoovers etc) with bare wires made sense as the person could fit a plug to match their wiring.

          Most plugs now are the molded to the cable/not user serviceable kind now though…

          even so, in the UK most outlets are fed from a 32A (sometimes 16A) breaker on a 240v circuit.
          If you searched for Nema 6-15 you’d find those plugs (similar voltage and current rating to UK) come as molded appliance plugs or user fit plugs too.

          djsmiley2k – I’m about the same age as you and this is something I’ve done a bunch of times, – it’s also something that was taught in school!

          notarealemail – he did mean household appliances. – and there are still some appliances that ship with a plug that you can take apart with a screw driver in the UK. molded appliance plugs are becoming more popular because they are easier to manufacture.

          1. last time I checked wiring a plug was still part of general secondary science class.
            the exception to the mass molding of leads seems to be lamps and extension leads.
            lamps of course it could be to facilitate swapping a bs546 plug however it seems very unlikely (just cutting the molded plug off is not recommended, leaving a plug with exposed wires ready to be plugged in by some child or idiot is generally frowned upon) more probably to do with no molding machine can handle the anemic cable!
            now of course it’s a legal requirement for electrical items sold to uk to have a suitable uk plug but it wasn’t so long ago, there is an episode where Mr. Bean buys a television set only to find that he must attach the plug to the cable himself although I cannot suggest trying to replicate his unique method.

      1. Probably more accurate to say mis-use of wire nuts. I’ve seen too many homeowner wiring jobs where they reuse their wire nuts, or just buy one size of large wire nut and use it on everything. Even those ceiling light fixtures with one 14g wire connected to one 18g stranded wire.

        I’ve seen burnt wire because of re-used or too large wire nuts.

        I never re-use wire nuts. I buy several sizes, and only use the size just big enough for the wires I need to join. And use them as little as possible.

        I wired up my garages, no wire nuts except on the ground wires where necessary. A pair of double outlets in each box, with the incoming and outgoing wires connected via the screw terminals.

  4. I actually had the same exact problem with all of the AFCI breakers in my house. I was expecting to have to buy several expensive replacement breakers and was pleasantly surprised after I emailed Bob and Joe. They were very happy to send me completely free replacements. If I remember correctly, it only took a week or so for them to arrive too. It was very nice to see a manufacturer own up to a mistake and correct it without trying to charge the customer.

    1. I don’t know how, but you managed to take a completely unrelated post and make it political. Bravo – you are the off-topic king. You may pick up your crown of shame in the gift shop.

      Upvote: Humor

  5. Arc faults suck…
    2014 bed code requires them on all devices on a home except for bathroom, garages, unfinished spaces and outdoor receptacles.
    That means we have to arc fault all kitchen appliances (120v not 240). To make it extra fun we also have to gfci protect receptacles within 6′ of a sink base, this includes your fridge if it’s close to the sink.
    So now as an electrician, if at all possible, if the fridge is close to the sink I will try to put the fridge outlet on the far side of the fridge opening to try to get it outside the 6′ threshold.
    I will say that arcfault breakers keep us sparkles honest. No more accidentally sharing neutrals in large switch boxes with more than one circuit in them. And you better had been careful pushing that ground wire back because if it rests up against the neutral screws on a receptacle it will trip out the breaker.
    Some things to note:
    -arc faults require a load to trip. So just because the breaker doesn’t trip when you turn it on, that doesn’t mean your out of the woods.
    -your kitchen remodel could cost $400.00 more just in breaker costs, don’t shoot the installer, he’s just trying to get an inspection so he can be paid.
    -the “can you just change this outlet quickly” line makes the hair on the back of your electricians neck stand up- there is no such thing as a quick outlet change anymore.
    -don’t assume you can get a multi pole breaker to meet your needs, your brand of panel may not have one- don’t assume!
    -I do have to say over the years of installing arc fault breakers, the technology is improving. We’re also adapting our wiring methods- your more likely to get a new circuit than us taking the risk of using an old one. We are getting less call backs then before, but it does seem like random nonsense tripping of breakers is becoming sadly routine.

    1. GFCIs aren’t allowed on freezer outlets (well, maybe not recommended) because they can trip and spoil the contents of the freezer.
      Do the Arc Fault breakers have the same problem?

      1. Gfci outlets may not be recommended on freezer outlets by the manufacturer but may be required by the new due to the location of the receptacle servicing the appliance.
        The NEC took out any allowance to remove gfci requirement due to type of appliance a few code cycles ago now. The only exception is a dedicated fire/security systems ten receptacle.
        So if your sump is in an area requiring gfci receptacles it must be plugged into a gfci receptacle.
        If your sump is in an area requiring both gfci and arc fault protection it must have both gfci and arc fault protection- and lord help you during a flood.
        The NEC does not consider practicality in codes it’s only aim is to provide a safe electrical installation (you can find this line in the code book).
        The problem is that arc faults are still such a problem and are so expensive that people often now install them – get it insodvted- then remove the breakers and return them to the big orange box, often saving themselves well over a 1000 dollars and quite possibly nullifying their chance to recieve money due to a house fire.

  6. p.s. – that article is dated 11/29/13. And as I noted before. I have noticed, particularly in the last year or so, an improvement in arc fault technology as in less nuisance tripping.

  7. AFCI’s are in their infancy like GFCI’s were. This is where a GFCI/AFCI comes in handy. It is well known that most dishwasher fires could be prevented by using AFCI’s. Originally, they were, as far as I can remember, required in the last several years on a dishwasher circuit. Long before that a dishwashers should have been on a GFCI. A breaker that is an AFCI is required on things that if they go south can cause fires.

    Why anyone would start an appliance and either leave the house or go to sleep is beyond me.

    1. If the appliance is ready to start, I start it and happily take out the clean contents when I come back or get up. I did never think about babysitting these things, THIS idea “is beyond me”, they are built and programmed to work autonomously. They have leak proof systems for their water hoses and we have breakers in the house wiring, which is enclosed in the brick wall anyway.

  8. Watch the video Hackaday, those were GFCI, you can even read the label on in the video. Compliments to the man that took that video for knowing he shouldn’t be recording a vertical video, no thanks to him for continuing.

  9. While demonstrating my new 2m baofeng to a friend, the first press of the transmit button tripped his breakers. We found it was completely repeatable. I don’t know what type of breaker system he had, but this was in th UK.

  10. Something I learned the hard way is not to cheap out on AFCIs, some of them just use high pass filters and not band pass leading to false trips at as high as 100mhz

    But the better ones ($80+) work very well even with multi-watt transmitters quite close to the box and with no issue with industrial 100khz kW switching supplies from my own experience

    And seeing how many lives these save I don’t recommend replacing them with basic breakers

    But I’m no electrician

  11. I’m confused… The HT in the photo is a UV-82HP, which, as the name suggests, only transmits UHF/VHF, not 20m HF. So what is with the header photo? Was it staged for the article, or did someone actually try this with one and it really caused problems and that just didn’t make it into the article?



    1) https://www.youtube.com/watch?v=2qbKp0zveNo

    2) https://www.youtube.com/watch?v=_2HyTRxzwXs

    3) https://www.youtube.com/watch?v=vdGcxu84IHw

    4) https://www.youtube.com/watch?v=iLmC5quELrE

    “__________________________________________________ __
    2-65 Log #1274 NEC-P02 Final Action: Hold
    __________________________________________________ __
    Submitter: James W. Carpenter, International Association of Electrical
    Comment on Proposal No: 2-153
    Recommendation: We support the panel’s action for rejection of this proposal.

    Substantiation: AFCI technology was first introduced in the early 1990s and has been included in the code development process in the 1999, 2002, 2005, and 2008 editions. AFCI requirements have been a progressive process, as well as substantiated over the past four NEC Code cycles.

    Accordingly, this Code Panel has gradually expanded the AFCI protection
    requirements over numerous code cycles with the intent to increase electrical safety in the home, but do so on a gradual basis. However, the expansion of AFCI requirements didn’t come without extensive deliberation by the panel, based on sound technical substantiation and data.

    The following past ROPs & ROCs below clearly establish the Panel’s long
    history and technical discussions, which has resulted in an equitable code that ensures a minimum level of safety.

    NFPA 70 1999 Proposals 2-128, 2-129, 2-130
    NFPA 70 1999 Comments 2-56, 2-65, 2-66, 2-67, 2-68, 2-69, 2-70, 2-85
    NFPA 70 2002 Proposals 2-102, 2-103, 2-106, 2-110, 2-112, 2-113, 2 115, 2-116
    NFPA 70 2002 Comments 2-71, 2-78, 2-79, 2-80, 2-81, 2-82
    NFPA 70 2005 Proposals 2-123, 2-133, 2-134, 2-142, 2-146, 2-149, 2 150, 2-134a, 2-161, 2-167
    NFPA 70 2005 Comments 2-87a, 2-93, 2-105, 2-108, 2-110
    NFPA 70 2008 Proposals 2-142, 2-126
    NFPA 70 2008 Comments 2-95, 2-129, 2-137

    As stated by CMP 2 Members F. Coluccio, R. LaRocca and J. Pauley, acceptance of this proposal would remove AFCI protection for parallel arcing faults from the first portion of the branch circuit, which is in direct conflict to past panel actions to increase safety. Rejecting this proposal will ensure the level of safety for these branch circuits are not reduced.

    The submitter’s substantiation lacks merit as the Standard for AFCIs, UL 1699, doesn’t consider as a component, the proximity to an arcing source.

    Regarding costs associated with metal raceways or cables, the submitter has not provided any cost analysis or data to demonstrate what is too cost prohibitive. In addition, CMP 2’s panel statement from the 2002 ROP (2-106) further supports this concept:

    “AFCIs Listed to UL 1699 are available, and the standard addresses efficacy, unwanted (nuisance) operation and operation inhibition. Cost should not be an issue for the panel to resolve. The panel reviewed a large amount of data, heard presentations on various positions on AFCIs, and received public comment on the topic. Upon that review, the panel arrived at the requirements in the 1999 NEC and continues to support that established position.”

    With respect to the state adoption, states throughout the U.S. continue to recognize and adopt the important safety provisions included in the 2008 NEC, despite the opposition from some industry groups. The panel needs to rise above the political battlefield and continue to move forward with what is in the best interest of safety for citizens.

    In the panel statement ROP 2-166, the Code-Making Panel stresses that “AFCI protection is for protection from fire ignition for branch circuits.” Consequently, with this statement and others in the past… the entire branch circuit shall be protected.”

    In the panel statement from ROP 2-155: “AFCI devices are widely available in the market and the panel notes that the cost has already come down since the introduction of AFCIs into the 1999 NEC.” Therefore, cost should not be considered.

    With regards to the substantiation that “wiring insulation has dramatically improved in the past 50 years.” This is a consideration that should be addressed from the original proposal in 1999 and reviewed as to the comparison of Consumer Product Safety Commission fundamental data as to eliminate the AFCI requirement completely based on the introduction of 90 degree C insulation.

    As indicated with this substantiation, the crisis with home structure fire civilian death, it appears that “Cord and Plugs” cord-and-attachment-plug connection accounts for the significant share in 2002-2005 concerning this issue. If it is the cords of appliances and equipment that are of apprehension, then AFCI and/or leakage-current detector-interrupter protection may need to be applied to the product standard as with NEC section 440.64 and addressed by Code-Making Panels 17 and 18.

    Should we disregard the past panel action concerning AFCI outlets many other consequences will occur. This will challenge the wisdom that the electrical industry’s leaders have credible knowledge. We have discussed, assessed, informed, and legislated the concept of the entire branch circuit being protected as referenced from zone 1 Consumer Product Safety Commission study, where 36% of residential electrical fires occur. This change will provide the information for state and local jurisdictions to amend this entire section from the National Electrical Code.”


    1. “Should we disregard the past panel action concerning AFCI outlets many other consequences will occur. This will challenge the wisdom that the electrical industry’s leaders have credible knowledge. We have discussed, assessed, informed, and legislated the concept of the entire branch circuit being protected as referenced from zone 1 Consumer Product Safety Commission study, where 36% of residential electrical fires occur. This change will provide the information for state and local jurisdictions to amend this entire section from the National Electrical Code.””



  13. I wonder if this ever plays when the cops are doing a raid and stand outside with their radios.

    “The lights went out! he made us, shoot everybody, or at least the pet dog!”

  14. Several issues, First thats not a ham radio. Thats a radio that can be used on the ham bands. A low cost chineese radio with less than steller record for FCC complance Second based on the display label that radio isnt on a ham radio freq, but is on the nearby MURS band. SO not only is he operating the radio outside the ham bands he is operating the radio on a band that the radio is not certified for.

  15. if the breakers are using electronics to decide when to trip, then why not just have an amp meter built in? if it goes over the amp rating, then the breaker trips.

  16. If you have one of these that’s giving you an issue – contact the manufacturer before purchasing a replacement. There are known issues and ACFI units are all marked with date codes that can identify the software revision. The manufacture can provide a newer unit if the unit you have has a known issue.

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