We have a very old house, circa 1850-1900. It seems that as often as every week we have had to replace an electronic device. In the past six months, we have had to in total, replace:

  • 1 washing machine
  • 1 refrigerator
  • 1 PC motherboard (of my custom PC)
  • 1 laptop
  • 3 laptop chargers
  • 4 hard drives
  • 1 tv
  • 1 monitor
  • 1 Nvidia shield remote
  • 1 PLC controller board
  • 4 modems and routers
  • 1 plug in smoke alarm

I tested all outlets in the house for voltage, they all test 108-120 volts, AC. Within reason, correct? Under full load, every circuit stays above 108 volts. Polarity is correct on all plugs but one, which is never used. All electronics (that can be) are protected by at least a 2000 joule surge protector, a piece.

No one in my family knows what is going on. Most of the insulation is tar, and hemp, however, there seems to be nothing wrong with the circuit, as I said. I have taken every measure (that I know of) myself to diagnose my problem, but came back empty handed. Any suggestions?

The only other thing I could say is that my area seems to be really weird with electromagnetic radiation. Half of the time, we can't get a local radio station broadcasted no more than 20 miles away. We can't get any AM half the time either. Could there be something there? Or would it just be something to have FirstEnergy look at?

  • 8
    I'd have to your power company check for burned neutral connections on your main power feed. You suggest your using surge suppressors but you indicated your house is from the ungrounded era, surge suppressors need a proper ground to work, is that taken care of?
    – Tyson
    Nov 26, 2016 at 14:09
  • 4
    Were your radio tests performed on battery-powered receivers to eliminate wiring issues?
    – Agent_L
    Nov 26, 2016 at 19:28
  • 2
    One thing I would like to say about the PC situation. Use a good UPS with built in surge protection. This is a good idea even for new construction if you have an expensive custom built rig. Nov 26, 2016 at 23:19
  • 3
    If your home has wiring from the late 1800s, especially if it has "copper insulation," it's time for a full wiring upgrade, even if your wiring isn't the cause of these specific issues.
    – WBT
    Nov 27, 2016 at 15:13
  • 3
    now, as a computer tech with little housing wiring knowledge - i will tell you just this: spikes, surges, brown and blackouts all damage your circuitry. If your house lights change brightness regularly, that is why all of your things keep breaking....something something call your electrical company
    – RozzA
    Nov 27, 2016 at 20:29

11 Answers 11


No, 108V is NOT "within reason". You have all the symptoms of a VERY SERIOUS power wiring problem. You should consult a licensed electrician immediately before your house burns down. The symptoms you describe suggest that your power wiring could catch your house on fire at any moment. Seriously, this is not something to fool around with.

  • 13
    Call your power company. Get them to check their equipment. The AM radio issue leads me to think this is a service transformer issue.
    – Dan D.
    Nov 26, 2016 at 6:26
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    Not disputing what you say, but didn't the US once have nominal 110V - or is that my faulty memory? If so, is it possible that somehow this house (transformer / whatever) got 'left' on nominal 110V in which case 108V is fine?
    – abligh
    Nov 26, 2016 at 9:46
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    @abligh IIRC 120V right now – and historical things wouldn't apply to the present, would they? Nov 26, 2016 at 10:00
  • 3
    List of mains voltages for each country, 100, 110, 115, 120, 127, 220, 230, and 240 V. United States is listed as 120 V. Nov 26, 2016 at 12:04
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    @abligh, there is a small chance that 108V is "fine", even in the USA -- but not in a house that also has 120V! That means there are serious wiring faults in those circuits that measure 108V. Somewhere something is getting dangerously hot. Nov 26, 2016 at 23:13

In addition to what @RichardCrowley says (and he's right, do call the power company), just because you measure 108V-120V that doesn't mean that there are no transients that spike much higher. Equipment dies infrequently from undervoltage, but often dies from overvoltage - particularly electronic equipment where a specific component (perhaps metal oxide varistor) in the power supply deliberately goes short circuit and blows an (internal) fuse under such circumstances.

Your surge protector may be junk, or may not be good enough (neither is uncommon).

Causes of such transients can include lightning strike, very heavy inductive loads nearby matched with a poor supply, faulty supply transformers, or electronic warfare (though I'm guessing you haven't been annoying any nation states).

In any case the answer is the same (electronic warfare aside): call the power company.

  • 6
    Don't think I angered any nation states. Don't think I angered the government. So, electric company it is. Nov 28, 2016 at 0:31
  • Another obvious cause of transients is arc-faults - connections so poor that they are actually creating arcs when current is drawn through them. These types of faults are extreme fire hazards and can also generate EMF that would interfere with things like @matthapkidokarate 's radio. They would also cause the odd RMS voltage drops in places around the house.
    – J...
    Nov 30, 2016 at 9:11

Most houses in the USA receive two "hot" wires which supply current in opposite directions at any given time along with a neutral wire. If the loads served by both not wires are perfectly balanced, no current will need to flow in the neutral. Otherwise the current in the neutral will be the difference between the currents in both legs.

If the neutral becomes disconnected but the loads on both sides are perfectly balanced (not a common situation), everything will work normally [since there would be no need for the neutral wire to carry any current]. If the neutral is disconnected but the two sides are not balanced (a more common situation) the side which is more heavily loaded will receive less voltage than the side which is less heavily loaded, but the amounts of voltage will go up and down depending upon loads.

The only way some outlets would be able to receive 108 volts while others are receiving 120 would be if a huge amount of power is being dissipated somewhere continuously (so much so that something would be quote noticeably hot) or there's an open neutral somewhere that's allowing some devices to receive more voltage than they should while others receive less. Open neutrals can be extremely destructive and dangerous, and your description makes that sound like a possibility.

  • Makes sense. I know that although the circuits are (usually) balanced, I know that things seem to go wrong when we notice them on big load changes, such as turning on light fixtures or dryers. I have suspected frequent brown outs before, as we are the third to last utility transformer in the line, receiving only single phase (all be it 2 phase (180 degrees out of phase) like most us homes internally.) And, we have the very rare (only twice) shock from a grounded part of anything, it may be possible that at all plugs may have the grounding bound to the grounded conductor, explaining the shock. Nov 28, 2016 at 0:20
  • I have noticed that those two shocks have only happened during extreamly (unbalanced I believe) high load. Hardly enough to establish a pattern, but, may be causing an issue with electronics. I remember, back a few years ago when a family member used a blow dryer every day, we would have to turn off everything else in the house. Possibly the same issue with the voltage potential between the grounded and grounding conductor where there should be none. The more I read the US electrical code, the stupider I feel. Nov 28, 2016 at 0:23
  • @matthapkidokarate Getting shocked on a grounded wire is never a good sign - are the outlets themselves grounded? Is there a main grounding rod (a metal rod, sunk in the ground, with a single wire running to it, usually somewhere near the breaker box/incoming power)? If not, that by itself could explain the dying electronics. All in all, it sounds like your wiring really needs replaced/updated...
    – ArmanX
    Nov 29, 2016 at 18:50
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    @matthapkidokarate: If you know of two breakers on opposite phases from which you could unplug everything, I'd suggest unplugging everything from those two breakers, turning off the main and then all the other breakers (turn off main FIRST!) and then turning main back on and measuring the voltages on those two circuits. Then plug a heater into one and switch it on, and measure the voltage on the other. If the voltage on the side opposite the heater goes UP, that would imply a problem in the grounded/neutral conductor somewhere between the utility's transformer and the heater.
    – supercat
    Nov 29, 2016 at 19:23
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    I echo the bad ground issue. I had a house issue where the ground connection behind the meter (power co ground ) had rusted from water intrusion and was causing split loads as bad as 85/155 V
    – casey
    Nov 30, 2016 at 0:19

Your house may have been built 1850-1900, but surely the electrical wiring isn't over 100 years old? If it is, replace it now. All of it.

  • 3
    +1 Having just completed my first renovation, a full house rewire will be top of the cards for any future purchase. Our house actually had wiring less than 30 years old - done exceptionally badly and with already flaky insulation. It also had a lot of original wiring (now dead) and it was incredible how it had just deteriorated. I have no doubt there are houses in the street using that original wiring and, well, they're just fires waiting to happen.
    – Dan
    Nov 27, 2016 at 21:35
  • What did the wiring look like in 1850?
    – DMoore
    Nov 29, 2016 at 6:51

Since there seems to be some debate in the comments: here is the standard on voltage tolerances in the US. For point-of-utilization, the requirement is 110V-125V for lighting circuits, 108V-126V for everything else.

However, they allow a range of 106V-127V, with the stipulation that

[This range] includes voltages above and below [normal] limits that necessarily result from practical design and operating conditions on supply or user systems, or both. Although such conditions are a part of practical operations, they shall be limited in extent, frequency, and duration. When they occur, on a sustained basis, corrective measures shall be undertaken within a reasonable time to improve voltages to meet [normal] requirements.

In other words, seeing 108V on any circuit that supplies lights is unacceptable, and should be corrected by your electric company.

(Additionally, it's extremely unusual to see a swing of 12V in outlets within the same house. That's something they should also correct)


In Canada (which I believe is the same in the U.S.), a residential feed is 3 wires; insulation on each conductor is color-coded red and black for two power phases and white for neutral. Across red and black is a nominal 240V, between red and white or between black and white is a nominal 120V. The white neutral wire should always be at ground potential, and in a properly balanced service, there should be little or no current flowing in the white wire to/from the house (although in practice there is bound to always be some imbalance). All outlet boxes should be grounded back to the service panel, which in turn should be grounded to well... ground. I think the neutral is supposed to be grounded at the utility company transformer for your house, to keep the neutral at ground potential (although I don't recall if it is bonded at the service panel as well or instead).

Bottom line: perhaps the problem is that neutral is floating with respect to ground. If so, this could be responsible for the damage to your electronics and appliances, and would be very dangerous as both a fire and electrocution hazard. Note that in the case of a floating neutral, you can measure any "hot" to neutral and always get the expected nominal 120V, while neutral to ground could be anything from zero to thousands of volts, in which case "hot" to ground would be that same zero to thousands of volts PLUS the 120. That could cause over-voltage failures in all sorts of devices, not to mention over-current failures in human hearts.

  • 3
    This bears repeating. Have an electrician check for a floating neutral. Nov 28, 2016 at 10:17
  • In a 150 year old house I would be very surprised to see 3 wires properly colour coded given the OP stated most of the wiring was tar and hemp insulated. I'd even be surprised to see the hot and neutral consistently following the same path through the walls.
    – Myles
    Nov 28, 2016 at 20:11
  • @Myles I can understand that, but would hope the service onto the property is more up to date. Anyway, using the color codes was more to help the explanation of how it works (or is supposed to) than what the OP should expect to see.
    – Anthony X
    Nov 29, 2016 at 1:47

There is a large amount of information in the answers but one thing I do not see is a discussion on the grounding system. With a home of this age there were only 2 conductors run in the electrical system and the neutral was normally bonded to the water pipe. One of the issues I have come across in the last few years in older homes is the original water mains have been replaced with plastic pipe and no new ground rod driven (UFER grounds were not invented until World War 2 so unless the home has a new foundation it will not have this type of grounding system). I would suggest the addition of a minimum of 1 and possibly 2 new rods to be added and connected at the service panel with #6 copper wire. The surge arrestor not having a good ground would allow higher than normal transients on the line. The suppressors used by power company's clamp at higher values than home models and only limit the spikes when in line from the load (if there is a strike between the station and your home or large electric motors in use close to your home the sub station limiters don't limit your spikes). I mentioned Large electric motors do you live close to a industrial plant, do they still have electric busses (I used to live in Dayton and the busses create spikes also.)? Even several miles away when large motors are started or stopped the line voltage can swing and huge spikes may be present. A good solid ground to attach your surge suppressor to may be all that is needed. I have installed several large units (whole house suppressors/ arrestors) on homes that were on the same "Main feeder" as a Lumber Mill. The home(s) Had similar equipment losses to yours with newer wiring, after the install they quit losing equipment until the unit failed. I then installed a much larger system that has a monitor to show if it is working and have not been back for years other than to install similar systems in that neighborhood.


I'd go with 'dirty power' coming in as a first guess, probably as @abliegh suggested >very heavy inductive loads nearby<. That could also be the cause of AM interference. That is upstream of the meter, so the power company may not need to get in the house so may not shut you down. Power Quality Analyzer would be required. Better yet if it does a high speed datalogging to catch fast transients that you would never see with a DMM.


It's important to note that electronic devices rely very heavily on the sine wave of the AC power coming into your house (60 Hz in the US). That's why there's two flavors of generators: regular (common and can run electrical equipment) and inverter generators. Knowing the difference can help you explain why your electronic equipment is failing (emphasis mine)

Conventional generators have been around for quite a while, and the basic concept behind them has remained essentially unchanged. They consist of an energy source, usually a fossil fuel such as diesel, propane or gasoline, which powers a motor attached to an alternator that produces electricity. The motor must run at a constant speed (usually 3600 rpm) to produce the standard current that most household uses require (in the U.S., typically 120 Volts AC @ 60 Hertz). If the engine’s rpm fluctuates, so will the frequency (Hertz) of electrical output.

With an inverter generator, the engine is connected to an efficient alternator, which produces AC electricity, just like a conventional generator. But then a rectifier is used to convert the AC power to DC and capacitors are used to smooth it out to a certain degree. The DC power is then “inverted” back into clean AC power of the desired frequency and voltage (e.g., 110-120VAC @ 60Hz). Regulation is very good and this system produces consistent power characteristics independent of the engine speed. The result is much “cleaner” power (“pure sine waves”) than is possible with a conventional generator, essentially the same quality of electricity that you typically get from your electric company. Why is this important? Well, more and more products today use some form of microprocessor. Not just your computer, but also your phones, TVs, game consoles, printers, DVD players, and even kitchen appliances and power tools. And all these microprocessors are very sensitive to the quality of the electricity they use. Using power that isn't "clean" can make these devices malfunction, or even damage them. So any application that uses sensitive electronics – and that includes a lot more things than you might think – will likely benefit substantially from the cleaner power provided by an inverter generator.

A clean sine wave looks like this

(image source)

Based on the other answers, it sounds like your wiring has been damaged. The fact that you're getting EMF interference would also lead me to think that this is the cause of your problems. Even if your wiring is "fine", it may not have sufficient shielding to prevent spikes (modern wire insulation provides some limited EMF shielding).

You'll need a trained electrician, to be sure. But make certain, whatever you do, that they confirm you're getting a clean 60Hz. Even a small variance will cause all sorts of problems for computers, up to, and including, failure.

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    Most electronics these days exactly do not rely on it much - many of the commonly used switchmode power supplies would be fine with you feeding them DC! Nov 28, 2016 at 10:19

It's almost certainly caused by some part of the circuit having an intermittent connection. Any inductive load on such a circuit would send voltage spikes throughout the rest of the system.

A bad connection like that can produce a LOT of heat. It can easily get to the point of melting the contacts, creating sparks, and so easily lead to fire. Honestly, it's amazing your house is anything but ash.

Tar + hemp + 1000° = fire


One more factor:

It sounds like you are using ordinary cheap surge suppressors. These devices have a very serious flaw: They are sacrificial in nature, there's a MOV (or perhaps more than one) in there that absorbs small surges but when it eats a big one it dies. Next time around there's no surge protection. No such strip can actually indicate if it's working, the lights are a lie. (At best indicating whether the MOV was blown up, something that can happen when it eats a big one.)

The normal advice is after a big surge you replace the suppressors--obviously not an option for you given how often it's happening. The other alternative is the much more expensive units that don't use MOVs.

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