What is a Lost Neutral? Lost Neutrals demonstrated

What is a lost neutral? A lost neutral can be very dangerous and can damage electronic equipment in your home. Do you have fluctuating voltage in your home? Do lights get dim and/or brighter? Do appliances seem to have less power or more power when they are operating? This video will show you exactly what a lost neutral is and what the results of a lost neutral are. It uses real-life demonstrations and animations to show exactly how a lost neutral works.

- - - - - - CHAPTERS - - - - - -
00:00:25 - Losing a neutral demo
00:01:08 - What causes a lost neutral
00:01:55 - How a typical electrical system works
00:05:32 - Lost neutral animation
00:07:00 - Lost neutral demonstration with light board
00:10:10 - 212 V on one lightbulb

[PowderMill]

I’m an electrical engineer, licensed electrical contractor and volunteer firefighter of 35+ years.
This is the very best demonstration of the risks posed by a “bad” or missing neutral.
It SHOULD be made mandatory training for anyone working in the trade.

Thank you!

[Mark-zuwp]

I worked for electric utility company 36 years and learned all about bad neutrals and repaired many neutrals. When I retired they brought me back a trainer and one of the things I taught was open and bad neutrals. What they caused we called a power surge due to the imbalance of in coming service voltage. This is not to be confused with a power surge that occurs during lightening storms in the south. The purpose of the neutral in a 3wire or 4 wire service is to balance the hot legs. That was the only answer accepted on the final exam. Also many believe it is ok to touch a neural with bare hands. As long as everything is connected properly you shouldn't receive a shock. How ever if there is a neutral problem somewhere you will receive a shock just as if you touched the hot wire. It's all fun stuff but always be careful and ware your PPE. Better to be safe than dead.

[tedlahm]

Absolutely fantastic animation and demonstration.

[odieFeng]

Great explanation. I think I finally understand how this lost neutral thing works.

[jimruthem]

Understood open neutral but your explanation of Lost neutral was an education. Thank you!

[JunkyardDigs]

This happened last night during a wind storm, I was confused as hell, since half the light worked, and the other half were bright as hell. Can't believe we didn't blow any bulbs or anything after 12 hours. Thanks for the explanation!

Edit: months later I would learn one of my friends backed into our telephone pole 😂

[ThatEEguy]

My dad worked in the water department of a local city. One day when he was working on a water main, they had to disconnect a house from the main to swap out a pipe. When they disconnected, the pipe sparked and the owner of the house came out yelling about his bulbs blowing. My guess, he and his neighbor shared a transformer, he lost his neutral between his house and pole, and his system was grounded to a water pipe. He was using his neighbors neutral through the water pipe, and my dad disconnected it when he separated the pipes.

[critterallywithjohnernest.]

I've been working with electricity all my life and never seen anything like this. Really great demonstration and easy to understand. Well done sir. We are never to old to learn and it is a never ending job of learning.

[miketaylor]

You’re great at explaining things and very well spoken. Nice job and thank you.

[fisqual]

I always kinda knew why the high/low voltages were happening but this explanation really solidified my knowledge of why. Thanks so much for the video!

[brianlittle]

⁠thanks for the reply. At 2:10 you said they were phases or legs. That’s two different things. Either way you look at it, it’s a single phase transformer. What we really mean when we mention phasing is time. Are the two legs out of time with one another? No they are not. There is nothing that can cause a delay. So they are in time. An oscilloscope would show a 120 volt sin wave or a 240 volt sin wave with their peaks being at 170 volts or 340 volts. The two legs do not add together to create 240 but rather we are breaking the 240 in half with the center tap. By doing so we are only changing the amplitude of the sin wave. All measurements are relative with respect to reference.

My phone always gives an error when replying to a comment so I have to leave another comment.

[NickFrom]

I've had to happen to me. A storm broke off a tree limb, which fell and broke the neutral from the transformer. It was a wild ride. My wife and I had a light fixture above the bed with incandescent bulbs in it. When the event happened we both were laying down but we sat up when the lights started going crazy and about one second later the bulbs in the fixture exploded and the glass fell onto our pillows. I jumped out of be do run down and flip the main disconnect but out of habit I hit the light switch for the stairway light. Poof, another bulb blows. I had to grab a flashlight to get to the panel which extended the time it took and I'm sure that caused some of the other devices to fry. I lost tv, vcr, some of the stereo, relay board in the range and who knows what else. A guest staying with us said the vcr was crackling like bacon frying and the tv looked like it was in the poltergeist movie. Honestly I'm surprised more devices didn't fry.

[FaysalKhalashi]

Thank you for sharing this video. It perfectly explains what happened in my house yesterday. Several electronic appliances exploded, and although the technicians managed to fix everything, they couldn't clearly explain the cause. After watching this, I finally understand what went wrong!

[victorbruce]

Friend bought an old house, old 2 wire no ground romex. Some later wiring added with ground. Got shocked in bathroom, even though had working GFI outlet. It tested okay, but everything supposed to be grounded, was HOT, intermittently. Overhead fixture, device frames, cover screws, etc.

After looking around, what was rewired, added over the years. The bathroom had been rewired with floating ground wire not connected back to panel. Along with added ceiling fans in nearby living room. A single tiny strand of hot wire on fan was sticking out of wire nut, touching floating ground wire. Creating intermittent shock hazard whenever fan switched on. Fixing that fault, running ground wire to panel, that problem was repaired.

Hard to tell what hazards lurk in walls and attics. Even if things seem to be working.

[goldCrystalhaze]

The best explanation i have ever received. Thank you for sharing your knowledge!

[apackwestbound]

Thank you for taking the time and effort to produce this excellent tutorial!

[vmax]

Excellent explanation/demonstration. Congrats and thank you.

[paulystark]

Just had FPL out and this was exactly my issue with dim lights with microwave, table saw etc. I always thought it was me replacing with smart switches, omitting 3-way red wire etc. thank you so much for giving me the kick to finally call them out instead of wasting hundreds on an electrician.

[SuperKONR]

Thank you for the time and effort you put into this demostration, it's very well done and I learned something new today!

[donpretlow]

Just had another issue with the neutral line going to the transformer on the pole. I had some strange power fluctuations again but not as drastic. So I put my clamp meter on one leg going into my panel. Then I turned every other breaker off putting a larger load on one leg. It showed a voltage delta of about 15 volts. I called FPL and they sent a service truck out. He pulled the meter and put a device on it to check and it showed it was just over the allowed difference. After inspecting the ground cable he saw where my neighbors tree was chafing the wire. It was warn down to a single strand. They replaced the neutral drop and it is now fixed.