Attack Of The Squirrels - Responses

One morning, three years ago, my family and I got up early to go on a trip. Suddenly, we saw smoke coming out of our TV, even when it was off. Immediately, my daughter screamed from the bathroom telling us that the light bulb exploded. My son yelled from his bedroom too, and my wife from the kitchen. It was pandemonium in our house. I had no idea what was going on.

After turning off the main panel breaker, I went out to check the transformer at the pole. I did not see any obvious damage in the transformer, but I saw the bare aluminum (neutral) wire cut. I called the power company, and when they came to check the problem, they told us that the squirrels ate the wire until it was cut. We lost all of our electronic equipment, two refrigerators, fire alarms, etc.

I have two questions: Is there anything the power company can do to the neutral wire to protect it from the rodents? What can I do to prevent future damage to our electronic components? Yesterday, I checked the wire and it looks like the squirrels already ate some sections of the neutral wire again. The power company does not take any responsibility for this, and they do not have a solution to the problem. Please advise!
Henry De Leon,

Over this past weekend I was in Lancaster, PA helping my son move to a new house. We met the next-door neighbor, who told me that she and her husband had inherited their house from his father. Not long before his death, the father had complained to his son about the squirrels eating the insulation off the wires in the attic of his 170-year-old house. The neighbors had inherited the house and moved there in April 2000. In September 2000, the house burned down from an electrical fire.

I think I will have to be more vigilant in getting rid of the flying squirrels in my attic.
Victor M. Ammons,

Response No. 1:
Very interesting. As a Fire Marshal who investigates fires, I have always heard about the rodents chewing the wires and, on occasion, starting a fire. I have never had a fire caused this way, nor the chance to examine the scene of one. I would very much appreciate any additional information, and pictures would be great. You always have to have an open mind (sometimes, easier said than done) when it comes to investigating fires. Thank you and be safe.

Response No. 2:
Another thing these rats with long fuzzy tails will do is to rip away the lead that is commonly used to cover the vent pipes that protrude through the roof of houses. This leads to water leaks, insect intrusion, etc., – all thanks to the common gray squirrel and his ilk. Of course, they also cause some very severe electrical surges when they try to go phase-to-phase on pole-mounted transformers! Sounds like we all need to eat more squirrels stew.
Rick Stevens,

Response No. 3:
It is obvious that neither home was updated electrically for a very long time. Otherwise, the ground rods and bonding to the water system would have protected the equipment from the 220 volts that destroyed everything. As far as squirrels chewing on the wiring in the attic, I think that would have also been eliminated if the wiring were updated since the ‘70s. I very rarely run into problems with animals anymore. At least not like we saw in the ‘60s and ‘70s. The father probably never had a heavy load on the wiring and when they moved in, they overloaded the circuits. Simple.
Ron Starr,

Response No. 4:
My only thought is to research if anyone makes an overvoltage relay that a homeowner can afford, or wants to afford, and connect that to trip out at, say, 150 to 200V between neutral and hot. Of course, you'd have to sense both hot-to-neutral voltages and then trip both phases (hots).

Another approach might be to install a GFCI main on the main panel. Either solution would be fairly expensive, and I did not research the availability of GFCI circuit breakers in the sizes commonly used in mains for residential applications. Note that the GFCI circuit breakers exist down to as small as 15 amps, but that doesn't mean they are listed as service-entrance equipment. You might have to mount a separate enclosed circuit breaker that's GFCI and use that as the service-entrance disconnect.

Additional research is definitely needed (a trip to your local major electrical supply house would be a good place, or contacting a reputable local larger electrical contractor that does work in residential and commercial might be another avenue).

Another solution using less "gadgets" would be to contact the electric company again and see if they'd install the service underground. You'll have to pay that cost and, since they didn't mention it, it may not be available in your service area.

Confused yet? If "No," I did not do my job well. (Just kidding, I hope) Good luck with solving this. Since the squirrels have already attacked again, it sounds like whatever you do, it's going to be a real challenge. Hey, here's another idea - seriously, how about contacting one of the environmental groups in your area? They may have some ideas in humane and effective rodent control. I think the key word here is effective. Good luck!
Frank Elliott,

Response No. 5:
A couple of things come to mind when I read articles like this. One, while the grounding system isn't supposed to take the place of the neutral conductor, it may have prevented the electrical components from going 120V to 240V once the neutral was lost. Second, what they may want to do is watch and see how the squirrels are getting to the wires. Maybe all they have to do is place a piece of thin tin sheeting around, say, the pole or tree so the squirrels can't climb up. If squirrels are getting into the attic, then there’s got to be an opening somewhere where they’re getting in. Take the time and seal up the hole. All that may be needed is a little time and investigation and I'm sure future occurrences of the squirrel attack can be prevented or at least minimized.
Craig Gates

Response No. 6:
There are sonic deterrent devices on the market that will not do any harm to the squirrels but the ultra-high frequency will tend to annoy them only. This will cause enough discomfort to encourage them to leave the area. Good luck!
Arthur Levin,

Response No. 7:
The "open neutral" problem is generally accepted as the most frequent cause of power problems, especially in residential installations where the G/N wire is also the physical carrier, as it is in most cases. In most NEC and UL requirements, there is an explicit prohibition on using a safety ground connection to provide a physical support. In residential service installations, this important design principle is abandoned, so the utility doesn't have to spend a few dollars extra to provide a separate carrier wire.

The utility could do many things to improve your situation, but they are unlikely to do anything unless you scream, and point to your history of problems. If that doesn't work, the state PUC would be your next step.

The line up through your meter is their responsibility to maintain, and their liability if something happens that creates damage. Underground power would be the best solution, if it were practical.

Good plug-in ("Point-of-use") surge protectors CAN protect equipment in your house. Panamax ( makes such protectors, and we provide a warranty against connected equipment damage from problems like the one you describe.  HOWEVER, the widely sold” whole house protectors," or meter socket protectors, installed at your service entrance, will NOT protect at all against open neutral/ground connections. This is true even for our own PRIMAX protectors.
Dr. Richard Cohen,

Response No. 8:
Most homeowners should have a water pipe or driven ground tied into their system. This prevents damage as described in your two letters. It should be in the electric Code.

If there is no electrical path back to the transformer (via earth or via the neutral on the service drop) you will expose your equipment to 240 volts. This path through the ground can only return to the transformer if the utility has alternate (common) grounding.

I have heard of squirrels chewing lead cables, but never experienced neutral wires failing from squirrels.
Tom Wissing,

Response No. 9:
Please explain in more detail how the squirrels eating the insulation off of the neutral wire caused your TV to smoke. The neutral conductor from the utility to the house is usually a bare conductor anyway. So why did it matter? Was there another bare wire that caused a fault? I also have a hard time believing that so-called electrical fires are really caused by electric.

Here is a quick story for you: A friend was building a house for himself (and he is a builder by trade) and before it was complete, there was a fire. The local fire investigators blamed the cause of fire on electrical. The owner/contractor did not accept this cause of fire and would not accept the report. He hired his own attorney and investigation team to look into this accident. It was then determined that the fire did not start from an electrical problem and that it was caused by the furnace exhaust/chimney. So, my point is, I don't believe all fires reported to be electrically related are true. I believe the fire marshals use them as a last resort when they really don't know what caused the fire.

I do believe that electrical fires exist, especially in older homes with fuses, and people replace fuses with the incorrect sizes or there is equipment with very bad cords etc. However, I also believe it is not as common as believed.
Brian D. Kimball,

Response No. 10:
I am an electrical contractor in Pago Pago, American Samoa, and we have a similar problem with rodents. We call our squirrels by a different name -RATS! They cause problems with chewing on the insulation of conductors in attics, walls, and even panelboards. One solution is to put a plastic cone around any overhead wiring leading to the house. This prevents them from getting to the house and (sorry you bunny huggers) but there is also Decon.
Peter Young,

Response No. 11:
I was working for Andrew Antennas at the time and we had a test facility in Plano, TX. I installed a new Varian KU band transmitter. It was supposed to run a test requiring it to have power on for 24 hours. About 12 hours into the test, smoke and sparks came out of the top. In talking to Varian field service, it was determined to be a manufacturing problem, and they would send me the parts to fix it.

The very next day we lost one leg coming into the building. All computers and equipment crashed. Everyone came running back, and blamed it on me and the new transmitter. Our service ran down the pole in conduit and under the parking lot to our building. A squirrel was on the pole touching the conduit when he chewed through the feed. About all that was left was a black spot and a little fur. We were down for 24 hours, while Dallas Power and Light re-pulled our feeds.

I also have had problems with them getting into attics. The only way I found to stop them is with hardware cloth over all vents to the roof or outside. I have personally seen them go thru vent hood exhaust pipes. How they could get traction on the sheet metal is beyond me. That’s when we started using hardware cloth, and we haven't had any surprise visitors since. Rodents’ teeth grow fast; they need to chew to keep their teeth worn down. The only solution is to keep them out!
Don Geierman,

Response No. 12:
This story shows how serious it is to have a neutral severed.  We are so used to having single-phase, three-wire distribution systems, it doesn't occur to us how potentially damaging it is to have a neutral severed.  We have millions of houses susceptible to damage or fires when this happens.  When strange things begin to occur, as described, shut down your main panel and call the utility.  I know of no other remedy, other than to rewire with your house as a single-phase, two-wire system, and you know that is not going to happen.

I do have a suggestion though. Perhaps someone makes an alarm that monitors the voltages between each system's hot wires and the neutral and compares them.  Usually the voltages are equal and opposite in-phase.  When the neutral is severed, they lose that relationship with each other and an alarm can be triggered. What do you think? Alvin Havens,

Response No. 13:
If you could discover, by asking a professional or by trial and error, a substance that the squirrels find to have a foul odor or a bad taste (or both), and then have the power company rub this substance on the wires (do not attempt yourself), as long as it doesn't degrade the insulation on the wires, it might work.

As for squirrels in the attic, use foam and/or silicone sealant for cracks and crevices and staple hardware cloth (available at your local hardware store) to cover larger holes.

And, if all else fails, a good quality BB-gun might be just the thing to use.
Adam Ensign,

Response No. 14:
These are interesting stories. I cannot wait until the answers are in. I too have encountered neutral damage to services with the same results. I am usually called when a fire develops.
Jeff Crain,

Response No. 15:
Maybe the power companies should consider placing some sort of covering over the conductor that is foul tasting to the rodents, much like they have on underground gas pipelines.

Response No. 16:
I have the same problem. Squirrels are getting into my attic and eating the insulation off my wires. I noticed it was everywhere there was a place to set. I replaced the wires and lifted them up off the rafters. A friend told me to get a cat.

Response No. 17:
Been there, done that! We also had flying squirrels in our attic spaces. As I am an electrician, our house in now wired in EMT conduit, FMC, and MC cable.

Response No. 18:
Rodents that are famished will eat just about anything but aluminum wire is a first for me. Years ago, working for Rockwell on the Saturn II (Apollo) booster test firing, rats ate through our cabling, armor included, in the cable troughs at the test site in the Santa Susanna mountains here in So. California. The answer was to bring a bunch of cats in there to control the rodents.  The answer with squirrels was to leave a pile of peanuts for them daily, and then they will leave your wiring alone (my cousin’s husband feeds his neighborhood squirrels peanuts regularly).

Seriously, it is about time ALL communities go to underground armored cabling, and do away with pole pigs and unsightly weather-exposed wiring. My community has had underground wiring since my home was built 32 years ago. It is shocking to see all the exposed degrading wiring on tilting poles in older communities, without even a thought to go underground.  Here in earthquake country, underground is a must.  Yes, it will cost money, but done slowly over a long period of time, it can be done within a reasonable budget.  There should be a national goal to achieve this. It will benefit society as a whole, and provide a lot of jobs for young electricians in the rough. 
Ed Cohn,

Response No. 19:
I am an apprentice electrician with PG&E in California.  Before I got my apprenticeship, I worked as a utility worker in the line department.  What happened is pretty common; I have seen a few homes where the ground from the service drop failed.  In all of the failures that I have seen, the wire corroded at the splice on the customer's periscope, or on the splice up on the secondary wires on the pole.  Some of the older triplex service wires can fail too. The insulation will turn white and crack open, and the wires will corrode and eventually short or open.  In any case, damage to the customer’s electric appliances would be prevented by a good ground that is up to Code at the service to the home.

Another thing to do is just look up and inspect the wires to the home. If anything looks corroded, or shoddy, call your local utility company to inspect it, and repair it if it is bad.  Above all, a good ground at the home is a must. It will prevent any damage should that wire open, and the ground is usually the first to fail since the wire is bare and the splices are bare and exposed to the elements, where the other wires are insulated, and the splices are too.

As for animal damage, maybe a plastic cone of some sort could be installed around the service periscope to prevent critters from climbing up it.
Peter Jereb,

Response No. 20:
I have found that mothballs drive the fuzzy little rodents’ right out. It also works well for mice. Follow the direction on the box; i.e., use gloves and a mask. Camphor can cause cancer.
Mike Jennette,

Response No. 21:
Squirrels can be rough on electrical equipment. The entire campus of NC State University was without power once because an unfortunate squirrel shorted out the substation.
Richard D. Currin Jr.,

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