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Robert A. Wilber
Electrical Contracting
King of Prussia, PA   19406

Philadelphia Licensed
Master Electrician

Philadelphia Licensed Electrician 3516 16765 - Link to Philadelphia L+I

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Electrical contractor. Licensed electricians serving you in the City of Philadelphia, Delaware, Chester, Bucks and Montgomery county area in Pennsylvania for 40 years.

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CPSC Wiring Hazards Manual [downloadable pdf file] - Opens in new window! The Consumer Product Safety Commission (CPSC) developed this guide to warning signs of potential home wiring hazards and suggestions for mitigating these hazards. The guide is intended to help homeowners locate electrical dangers in their home before these hazards can cause fires or electrical shock. Although it provides guidance for pinpointing problems in the home's electrical system, it is not an instructional manual for repairing defective electrical systems.

Prepared by
U.S. Consumer Product Safety Commission

40 pages

CPSC Aluminum Wiring Publication [downloadable pdf file] - Opens in new window! The Consumer Product Safety Commission (CPSC) developed this guide to understanding aluminum wiring. The guide is intended to help homeowners, although it is not an instructional manual for repairing defective electrical systems.

Prepared by
U.S. Consumer Product Safety Commission

4 pages
In Philadelphia, it is unlawful for anyone except an individual licensed by the City of Philadelphia to install electrical equipment and wiring. Homeowners and Handymen are not allowed to install wiring. The owner of any property wherein any such installation is discovered shall be issued a violation by the Department of Licenses and Inspections. The limited exceptions include replacing devices and fixtures at existing outlets. Contact the Department of Licenses and Inspections for more information. Inquiry response by Phila. License and Inspections - Feb 2010

The lights in my house are flickering .... what is wrong?
Is my house going to burn down ... again?
Can a 120 volt appliance be plugged into a regular 110 volt receptacle outlet?
Did we damage the fuse panel?
I have a 200-amp panel that is making some noise ...
How much electricity does one person consume in a day?
How can I plug a four prong dryer or range into a three prong outlet?
I hear this buzzing sound ...
Lightning effects ...
Was it the plug or the receptacle that failed?
Everything electrical in the house got smoked ...
I have this voltage problem with a transformer and UPS system...
I have this voltage problem ...
Is this wiring diagram correct?
Is knob and tube wiring safe?
I did my own electrical repair. Is this right?
Can I do my own electrical repairs?
Voltage drop-off e-mail inquiry
Electrical Home Safety
Helping shock victims
Why do my light bulbs burn out so fast?

bullet gif The lights in my house are flickering .... what is wrong?
OK. this question is about A mobile home A trailer
It's kinda old. I think it was made in the 1970's
This is A major problem that occurred A few months ago.
As it stands right now the electricity in the home is very weak, and what I mean by that is that I can't seem to use any type of appliance, or device that draws a lot of power.
Some examples are I can't use A refrigerator, A stove, air conditioner, microwave, A washer or dryer,
Electrical heating won't work, and so on anything that requires a lot of power won't work.
But on the other hand I can still turn on my lights, all the regular lights in the whole home will still work, but they do blink A few times, but the lights will still work.
My television will still come on, and work, but the funny thing about that is that in order for the TV to remain on I have to leave 2 of the lights on in the living room because that's where the TV is at so in order for the TV to stay on I have to leave 2 of the lights on in the living room because the TV will not stay on if those lights are off it's like the TV needs those 2 lights turned on to work it's weird.
The hot water heater still works as well I can still get hot water.
So basically it seems like some of the things that don't need much power will still work, and the things that do need a lot of power will not work.
I'm not very skilled at anything electric so I don't know what it is.
And like I said this happened A few months ago everything was fine, and working, and then I came home one day, and I noticed that something was not right things seem to be messed up.
But any advice that you could give me world be greatly appreciated thanks.

You said a trailer, which could mean that you have a 30-amp 120-volt power supply for a travel trailer.
I will address this as if you have a 120/240 volt service like a house.
I am saying this because of your observation that the water heater works normally, which is most likely a 240 volt unit.
That being the case, my initial and strongest instinct is that you have an open, or high resistance, neutral conductor in the service.
The symptoms you observe are the product of a basic resistance/load configuration shift caused by the electrical imbalance created by the loss of the normal neutral path.
This is a not uncommon problem.
This is not a repair for a handyman or the unskilled.
Fortunately, the repair is often inexpensive, as the most common points of general neutral failure are repaired by the utility company.
The likelihood that it is an issue which the utility will address is bolstered by the fact that the problem developed during the winter.
This suggests outside, rather than in your panel, and is probably weather related.
Corrosion, splice failure, broken connection due to a fallen limb, transformer connection and so on.
Call your electric utility and ask for emergency repair.
Tell them to come out because you have power problems and you have been told you have an open service neutral.
They will come out and either fix the problem or tell you to get an electrician because it is in your meter enclosure or panel, which is your problem but unlikely.
Good luck.


bullet gif Is my house going to burn down ... again?
i had a house fire in 2000 from a faulty electrical outlet in my daughters room. was told that there was too much plugged in to the outlet. fireman explained that in most of the older holmes they needed to be updated to the new specs which most are not and with a lot of the neww electronics out now its a fire waiting to happen because too much is plugged into the outlets. im guessing my hme is about 50 to 60ys old. ex-husband hired a contractor, wound up firiring him and decided he wanted to finished the work. he had some guy who said he was a electrician come in to do the wiring. when i finally moved back in almost after 2 years, the wiring of the house was still not complete. i have a 3 bedroom ranch style home, bath and half. my light in the hallway was not working. in my spare bedroom and part of the living room the plug in outlets along the side and front were not working. the dryer that i had placed in the garage was not properly hooked up and i had to unplug it because it was shocking me everytime i touched the doorhandle. have not used it since. in my daughters bedroom if i plugged something in the outlet along the front wall and plugged something in my bedroom along the back wall it would trip some of the outlets in my bedroom and this happen for a while until i just stop using the plug. one early morning around two or three, my fire alarms went off and would not shut off. there was nothing burning, i wind up calling the fire department they checked all outlets for hotpots came up with nothing and wind up having to disconnect 3 of the units because new standard have a alarm in all the bedrooms. my ex-husband back in 2009 came and rewired the socket in my daughters room. i was in my daughters room friday using my laptop, plugged the charger in another socket in her room, went to sleep, woke up the next morning smelt a funny odor, but i thought it was coming from outside because i had the windows up, around noonish when i was cleaning up the odor got stronger, still thinking it was coming from outside, i just happen for whatever reason to look at the charger battery that was plugged in and it was red hot and when i pulled the bed out the way discovered that it was just simmering and if i would have left out to go do something it could have very well possibly started anothe fire. well i panicked and found a pop sickle stick to try and disconnet the wires as not to stick my fingers there, i know this probably wasnt smart either, but it worked and it wind up knocking everything out in my bedroom. i tried to reset it at the breaker box but it did not come back on, so i left it alone. i already know because i was having all these other issues that this house is not properly wireand i also know that most electricians do not like going behind someoneelse. i honestly dont believe they brought my home up too code and have too much stuff on one circuit. am i looking at a whole house rewiring project? and what are the cost of something like this?

Sympathies for your misfortune. I am glad everyone is OK.
It was kind of the fireman to advise you that the fire was caused because there was too much plugged into the outlet. I am sure he is a very nice man and meant well.

A properly installed electrical system of whatever age, if properly maintained, cannot, under normal conditions, have "too much plugged into the outlet." The reason for this is that the outlet is designed and intended to carry the full available circuit current, with limited exceptions. One such would be where the home has knob and tube wiring, in which case there may be devices rated for fifteen amps on a circuit protected with a twenty-amp circuit protective device. The other would be in the case of a twenty-amp circuit with multiple outlets, whereby it is allowed to install fifteen-amp devices at the outlets. In the event of a single outlet on a twenty-amp circuit, the device would be required to be rated for twenty amps.

It is possible that your advisor meant that connected components had effectively reduced the protection provided by the device rating by using extension devices rated for less current and used to connect multiple appliances, lamps, etc., thereby overloading the extension cord. It is imperative to always utilize a circuit extension that meets or exceeds either circuit capacity or the load connected to it.

"Up to Code" is a misnomer, in that a building's systems are installed according to the most recent version of standards [NEC is a three-year cycle] adopted by the local "authority having jurisdiction." Many municipalities continue to enforce older codes, rather than adopt the newest published codes. For example, the current 2008 National Electrical Code [NFPA 70] was only just implemented in Philadelphia in 2010. Up until this time, the city had enforced the last previous version from 2005. I have encountered instances in other locations in which 10 year old versions are being enforced.

If fifty years old, your house was built according to the locally adopted NEC code from 1957 or 1954. If pre-war [WW2] it may have had knob and tube wiring.

In any case, since the whole place was rewired since 2000, it probably should have been wired according to the 1996 or 1999 NEC, whichever was adopted in your area. Unfortunately, it doesn't sound like the work was done professionally, nothing against your ex.

I don't know for sure that your house needs to be rewired.

I think you should hire a competent electrician to inspect your wiring.
Call your local municipal office. Ask if permits and inspections are required for electrical work. Get two lists from them, licensed electricians and electrical inspection agencies [unless the town inspects themselves]. Call the inspection agencies and find out if they are members of the International Association of Electrical Inspectors. Are they licensed and insured? [You don't want a home inspector.] Tell them you are looking for an electrical inspector.

When you get to talk to the inspectors, tell them you need a good electrician. Tell them you know they inspect for electricians and you want to know who they would call to work on their own house. Explain that you understand that they will be inspecting any work this electrician does, since they are recommending him because they know his work because they inspect him now.

The battery had nothing to do with your house wiring. The other problems you need to have someone look at.

Let me know how it works out, or if you need more help.


bullet gif Can a 120 volt appliance be plugged into a regular 110 volt receptacle outlet?
For simplicity's sake:
110 volts, 115 volts, 120 volts, 125 volts - all the same thing.
You get what you get, and have no say about it.
... and here's why ...
Thomas Edison [no kidding] invented the electric light bulb, and needed to distribute electricity to make it usable. He built a system based on 110 volts DC. It was uneconomical and had large conductors and big voltage drops.
George Westinghouse came up with the idea of using alternating current to transmit electricity. This was valuable, in that the voltage could be changed by the use of a transformer, which allowed the transmission of electricity at a higher voltage, thus reducing line losses due to conductor resistance.
The initial voltage level delivered to homes using the Westinghouse method was nominally 100 volts. Over the years, the secondary voltage has been incrementally raised to 110, then 115, and 120 until it is common today to find 125, 127 and 130 or 132 volts in homes.
The reason for this is the upward ratcheting of transmission voltages to allow for higher demand. Every time your neighbor buys a new device that requires electricity to run, it increases the demand for electrical current on your utility's service conductors. Since these wires are not changed to bigger cables [with lowered resistance due to larger conductor cross-section area] every time demand increases, the only variable under the utility control is voltage levels.
The only way to push a certain variable demanded current [which consumers define] through a fixed resistance [unchanging wire] is to increase the voltage [electrical pressure].

Read more about George Westinghouse


bullet gif Did we damage the fuse panel?
E-mail Subject: My landlord is angry at us.

My landlord is very angry with me.
My fiance replaced light fixtures in three rooms in our new house.
Our power was only working in one corner of the house when we moved in. This is how we were able to install the fixtures with out flipping the breaker.
Anyway, we transferred the power to our name, but the electricity was still out!
My landlord called her handyman, and he wrongfully informed her that my fiance's "backwards wiring" fried the entire fuse box which she had to replace for $750.
My dad's been in the electronics business for over 30 years. He says that's not possible. He said it'd only fry one fuse/breaker and not the whole box.
What do you think?
I need this in writing!

Thanks so much for you help!!!

Your dad is right.
Have the handyman put it in writing.
Let them sue.
Tell them it is not possible.
Call/write your local "authority having jurisdiction" - town, city, county, state, etc.
Their claim is just so much nonsense.
Quote me!


Robert Wilber Electrical Contracting
Philadelphia License # 3516 - 16765
Visit www.wilberelectrical.com


bullet gif I have a 200-amp panel that is making some noise ...
E-mail Subject: My circuit breaker panel is making a buzzing noise.

I have a 200-amp panel that is making some noise.
I don't know how long it has been making this noise, but I just noticed it.
It has to be new because I am sensitive to noise.
It's like a pulsating buzzing noise.
It actually goes for a while, then goes quiet.
The panel links to a 100-amp sub-panel upstairs.
The only new change was that the bathroom has been remodeled.
The bathroom isn't drawing off the panel now.
I have everything shut off.
Is this something to worry about?
Robert P.
I would be concerned.
Panels shouldn't make buzzing noises.
If it is not something obvious, like a doorbell transformer, I would be concerned that there is a loose fitting breaker and that the buzzing noise is the sound of the breaker/busbar contact point burning up under load.
A symptom might be a "hot" breaker.
I would have this inspected by someone qualified.
keep me posted


Robert Wilber Electrical Contracting
Philadelphia License # 3516 - 16765
Visit www.wilberelectrical.com


bullet gif How much electricity does one person consume in a day?
Fun question!
When I looked on the web for info, I found that in the USA we consumed 3.479 trillion [million million] kWh of electricity in 2003. If you estimate 300 million people, that would mean we each used over 10,000 kWh that year.
This assumes that we each consumed our equal share of all electricity produced, even if some of it was used to make the can your soda is in, or the tires on your car.
The quantity used goes up if you allow that we import more products than we export, which gives us a "hard" electricity import in power used to make imported sneakers, etc!
On the other hand, China, with 1 billion people, used a bit more than a third of the amount we did in 2003, giving them a per capita kWh consumption of 1,300 kWh.
Just divide the total used by 365 ... We all have to work for SOMETHING we want!


bullet gif How can I plug a four prong dryer or range into a three prong outlet?
This is one of the most commonly asked questions in FAQ forums about electricity and wiring.
It must be understood that new appliances will be designed to meet the newest standards.
It is not reasonable to expect someone to rewire their home because they need a new dryer or range [stove]!
According to the NEC [National Electrical Code], it is now required to isolate the neutral conductor from the appliance frame or chassis.
It used to be allowable to use the neutral as a grounding means by incorporating a link between the neutral and the chassis.
The problem with this is that, should the neutral become "open" at some point, the chassis or frame then becomes energized!
The answer to this safety issue was to require a separate grounding conductor in the cable feeding the appliance.
The NEC allows the replacement of the new four prong cord with a three prong cord for appliance replacements in existing installations only!
It is then required, when the cord is thusly replaced, to establish the frame grounding link from the chassis to the neutral.
Robert Wilber Electrical Contracting
Philadelphia License # 3516 16765
Visit www.wilberelectrical.com


bullet gif I hear this buzzing ...
Thanks for providing this service.
A few weeks ago, I heard a buzzing sound that appeared to be coming from my thermostat. I live in Florida and have a heat pump. Over time, the buzzing has gotten louder. It sounds like the buzzing from the ballast of a fluorescent light, a fairly loud one.
I turned off the thermostat and I put it in the cooling, heating and emergency heating settings and I still hear the buzz. Also, when I put my ear to the wall it doesn't sound like it is coming from the thermostat itself.
About a year ago, I put some coat hooks on the other side of the wall. About the same height as the thermostat. I drilled holes for the anchors and then put the screws in. The anchors/screws are about an inch long. The wall is about 5 inches thick. The studs are the new aluminum type not wood 2x4s. And there are also electrical switches on both sides of the wall about 18' below the height of the thermostat and coat hooks.
I am worried that this might be a serious electrical problem.
Hi Jim
Are any of the switches below the thermostat dimmers?
Have you tried turning off various breakers to eliminate the noise?
Switches are not dimmers.
I had not tried turning off breakers yet. I will try that tonight.
Also, it occurs to me that you can use a water goblet or paper cup as a stethoscope and isolate the noise source ...
... buzzing, not sizzling [like bacon frying], right?
I put my ear up to the thermostat and the wall last night. It was much louder when I put my ear against the wall. Though I'm not sure if that was because the thermostat was plastic. The sound was so loud that there wasn't much of a difference for a few feet around the area.
The sound is more a buzz like fluorescent lights ballast then a sizzling bacon sound.
Thanks again,
Have a basement?
Have you gone down to see if and where the sound is down there?
Have hot air heat? Does a duct run through the wall where the sound is coming from?
Any receptacles under the location?
Have you or anyone else opened up the boxes and examined the various splices in the boxes and terminal connections at the switches?
What do the switches control?
Does the noise go away if you turn the switches off? ... or something else in the house?
Got a scanner? ... digital camera? ... microphone?
Send me a floor plan, photos, an mp3 file of the noise...
Bathroom overhead? Pipes in wall? Cold water feed to toilet vibrating?
You say you had put anchors in the wall... did you pull the screws out to see it they are damaged, as if you had hit wires [though I think you would know ...]?
Have you asked anyone you know to listen to it? Maybe they will recognize the sound, or be able to help isolate the source.
After that, I'm stumped.
Cicadas? BEES?
I guess you are looking at local professional help, or a drywall saw...
Let me know what you find.
Good luck!
Keep me posted!
I really appreciate your help.
I just needed to look up. Though I had to pay $69 for that answer when I had the air conditioning company come out. My wife couldn't stand the noise any longer and made me call them out.
The doorbell chime/ringer was above the thermostat.
A year ago, I installed a new doorbell and the hole in the stucco wasn't big enough to accommodate the wires and new button. I meant to go back and fix it but, I tend to be lazy about those things (and as usual, they come back and cause other problems like this time). So what happened is when someone pushed it a few weeks ago, it broke one of the wires and I think it was shorting out? And that was making the doorbell chime buzz. It sounded just like a fluorescent light ballast. So I went and fixed the connection at the doorbell and the buzzing stopped.
Again, I really appreciate your help. I hope you get a lot of business up there. If I ever move to Philadelphia and need an electrician, I would only use you.


bullet gif Lightning effects ...
The wierdest thing happened!
We heard a buzzing sound and saw a blue flash come from our bathroom....we know this is bad but nothing was burned or is not working.
It has never happened before.
Our home is older and we have lived there for 8 years.
We turned off the breaker.
It is raining out.
What do you think this could be?
Any advice or thoughts would be appreciated
Dear Jen
I can think of two possibilities
1] Some piece of equipment failed, arced over, and completely burned up [without leaving a trace or tripping a breaker ... [unlikely]
2] Some manifestation of lightning [ball lightning is really strange] might explain what happened. you did mention it was raining ...
I would suggest you investigate the grounding scheme for your electrical service entrance equipment. Inadequate bonding can interfere with lightning dissipation. Make sure you have a good low-resistance [25 ohm] ground path and a ground rod [two if necessary].
best regards,


bullet gif Was it the plug or the receptacle that failed?
We had a new chest type freezer plugged into this outlet our old refridgerator freezer was in.
After a while the new freezer started making a loud click every time it started.
It was louder than the electric heater in the home.
Then early one morning we heard a noise. The wall around that outlet was black and the breaker was kicked out.
I tried to unplug it, one prong on the plug was melted on.
The appliance man said it was our outlet that caused the problem.
He said it did not have a tight fit on the plug, and the freezer wasn't getting enough current.
... and that's why we have to buy the freezer [that's under warranty] parts.
Was it the outlet? Or could it have been the freezer?.
There are basically two possibilities, based on the information you have provided:
1] The connection between the male cord connector [plug] and the receptacle device was loose-fitting due to age, metal fatigue, etc. and the resulting high resistance connection caused heat build-up at the receptacle, which led to the failure.
2] The internal connection between the conductor in the cord and the prong on the male cord cap failed inside the plug assembly, leading to the same result.
I would suggest that if all the damage is EXTERNAL to the receptacle device, and the heating damage is at the wire/prong junction, I would be inclined to suggest that it is the plug that failed.
On the other hand, if the prong from the cord cap is damaged at the receptacle end, and the receptacle is damaged internally, it was probably the receptacle.
Without seeing the devices involved it isn't possible to make a definitive determination.
In any case, it might require a forensic engineering analysis to prove the point, either way [unless it is obvious], which could cost several times the value of the freezer.
Let me know what you find....
Best of luck


bullet gif Everything electrical in the house got smoked ...
What could cause everthing in an entertainment center to start smoking and no longer work?
Including microwave, refrigerater, alarmclock, and computer!
Take a look at my Philadelphia electrician FAQ page and Philadelphia electrician weblog and read about open neutrals. Deadly...
Outside of that, you can consider:
a] Lightning [if you have really poor grounding, lightning will go ANYWHERE and EVERYWHERE!]
b] Utility company error [wrong tranformer installed on changeout, wrong tap selection, ...]. Anyone who shares your tranformer would have the same problem though, so ask your neighbors.
c] High voltage passthrough at transformer [utility equipment failure]. Neighbors would be affected as well. Ask the utility company if they had a problem. Contrary to what you may think, they won't try to hide a problem like this, if they are the root. It just isn't in their interest. Fixing things like this [and they DO happen sometimes] is all in the cost of doing business as a utility, and we all just pay an extra 1/4 cent a kilowatt for a month to cover the cost - really!
But my vote is voltage imbalances due to issues related to your neutral termination.
Let me know what you find....
Best of luck


bullet gif I have this voltage problem ...
hey robert ...
I have a good one.
I have a UPS system [* Bob note - Uninterruptible Power Supply, for all you non-electrical folk reading this] that runs normally until it relies on utility power to run the system.
Then things get crazy: my A phase reads 187 & my B phase 63.
I have traced source neutral back to MDP [* Bob note - Main Distribution Panel] and it is solidly connected throughout.
I will get normal readings with no load, but as soon as load is applied that's when the trouble starts.
The UPS has been checked out and is ok.
The only thing I can think of is the source neutral since the UPS creates its own and everything runs fine through the UPS.
Should I meg out the source neutral?
Any ideas?
Please help.
Sincerely, Mike G.
Hi Mike
Happy to help troubleshoot this problem
Let me clarify a few things for myself
You speak of A and B phases - do you have 3 phase or is it a 120/240 single phase system?
Since you speak of no C phase, I am assuming you have a 120/240 volt centertap neutral single phase service to the UPS from the MDP
If this is erroneous, please advise, or are you using 2 phases of a three phase system with a 208 highleg?
... not that it makes a real difference, as you can just ignore the high leg in this case...
My understanding from what you say is that the output of the UPS provides 120/240 with a common neutral and that the load shifts to the UPS only when utility power fails
Is this accomplished with a local transfer switch at the UPS?
When the UPS is operating, you get normal 120/240. Correct?
You are reading normal voltages with no load because there is no imbalance.
When you apply load, the voltages become erratic in direct relation to the imbalance of the loads on each leg.
You have a neutral that is not so solidly connected someplace.
wilberelectrical FAQ page reference question
electrical anything - my blog
Robert Wilber Electrical Contracting
Philadelphia License # 3516 16765
Visit www.wilberelectrical.com
[followup before response...]
This letter from someone else with similar problem
and Mike - just because the UPS works right doesn't mean that the transfer portion of the UPS works right
... probably just passes a load test
Run a temporary external neutral and connect loads bypassing the UPS to test ... Get the idea?
[attached letter is next/previous FAQ..]

I have this problem that is driving me nuts and I can't track it down .."
Thanks Robert
Now you see why I am confused
To answer your other questions I have 2 legs of a 480 volt 3 phase system feeding a general purpose transformer [no hi-leg]
The neutral passes straight through to a 2 position manual by-pass switch.
This neutral is for utility use only since the UPS creates its own.
The trouble starts only when utility power is applied and the system has to rely on source neutral.
Like I stated before, the source neutral appears to be intact.
That's why I was wondering if megging it out would work or using one of those new open neutral testers.
They are supposed to work under load conditions and this is important because the UPS I am talking about runs all the computers, registers, etc.. for a [discretely unnamed major national retail chain] and getting them to schedule a shutdown is near impossible.
So, you have a 480 primary with a 120/240 secondary feeding the UPS, right?
Nod your head up and down...
Forget the utility company, they aren't involved at all
YOU are the utility company
You can't have a bolted through neutral... there is none from the 480 that matters to your loads!
Back up and start thinking about this again...ok?
YOU DON"T HAVE A GOOD NEUTRAL.. trust me on this
Problems getting a shutdown? Tough - shut 'em down or let 'em run [with written notice!] and don't worry about it til they fry! [ ... and they will]
This needs to be repaired - I mean, they do know this is a problem, right?
The transformer secondary centertap connection wiring out to the UPS is done wrong or broken someplace, period!
Make sure the transformer is the right type [wouldn't THAT be ugly...]
Make sure the centertap is done right and grounded properly to provide a true neutral to derive 120/240
Make sure the UPS and switch work is done right and that the neutral is truly connected
Make sure the neutral passes through to the loads from the transformer
You can always create imbalanced dummy loads before the UPS and take voltage readings across your neutral splices to locate the bad connection.
Got an infrared tester? Look for a hot spot at a terminal or splice [but it sounds like it won't be hot any more..] maybe a burn mark?
Personally, I think you probably NEVER had a good neutral.
Think about this like a set of doorbells with a 240 feed to two 10-volt transformers connected in series for the bells
Parallel feed the transformer runs to the bells with batteries, la la la ...
Where does the neutral from the 120/240 fit in? It doesn't....
The voltages are throwing your thinking off.
Draw it out
Call if you like
Phone call from Mike:
Wrong transformer: 480 volt primary/straight 240 volt secondary with NO centertap.
Neutral from 480 volt MDP bolted through - classic floating neutral
Designed wrong, installed wrong, missed on inspection
The cost? Multiple instances of equipment damage due to excessive voltage.
[Read that tens of thousands of dollars!]


bullet gif I have this voltage problem ...
Hello Robert,
I have this problem that is driving me nuts and I can't track it down.
I have one circuit that only partially works.
The circuit consists of a number of outlets in a bedroom, 3 overhead lights, and a bathroom vent fan/light and vanity.
I started testing everything with a multi-meter.
The working outlets were getting the expected 120 volts, the others are only getting 60 volts.
It seems this problem occurred while a hair dryer was running.
I checked the circuit breakers a number of times.
There is a pair of 3 way switches that controls one of the lights, I changed those just in case.
One of the outlets is switch operated as well.
I also removed the vanity and overhead fan.
At this point it makes no sense to me. Any help would be appreciated.

Hi Brian
without seeing the layout of the circuit, I can only guess
... 256 ... that's an old joke, sorry
Electricity is dangerous!
You can be injured or killed!
Improper installations can cause fire, injury and death!
Should you be doing this yourself?)
Do more than one circuit breaker control the affected equipment/devices?
I take it the bathroom isn't up to snuff now
Hair dryers use a lot of power-high current means high load, probably blew a bad connection open - are you now having trouble at the outlet where the dryer was plugged in?
I would suspect:
a bad [burned] connection at a device [loose screw, or bad splice at a wirenut]
a bad neutral [same deal, or bad splice at a wirenut - means opening up boxes to locate bad splice]
open common neutral if there are 2 breakers involved. Is it on a 3 wire circuit?
Look at circuit and try to figure out how you would run the wires to the different devices [panel to good device to bad device ?] Easiest method before walls finished!
Look at last good device and first bad device as best bet! [Hope nobody hacked your job!]
If this doesn't get you straight, send me a floor plan with devices mapped out!
And exactly what doesn't work right?
keep me posted
call if you need
PS: It isn't the lights ...
Robert Wilber Electrical Contracting
Philadelphia License # 3516 16765
Visit www.wilberelectrical.com
Hi Robert,
I have no formal training, just a do-it-yourselfer (I'm sure that makes you cringe)
In any case I was able to trace the problem down to a faulty receptacle.
What was really throwing me was that the voltage was reading exactly half, and I could not completely follow the circuit.
As it turns out everything beyond one outlet tested at half the voltage.
I just took a shot and replaced the last receptacle that appears to feed the rest of the circuit and was testing at 120.
Once I did that everything worked peachy.


More bad news-

New Question [March 2010]:
I have approximately 60 volts at one outlet. All the other outlets in that room are OK (120volts)
Voltage is being measured with a volt/ohmeter...what is the problem?

Bob C

Appended Answer:
Let me guess.
You are using a digital meter, right?
Common problem called ghost voltage or phantom voltage with digis. It is caused by induced voltage on what are really dead conductors. [read more on WWW] I first ran into it thirty years ago and NOBODY knew what it was.
Use a solenoid-type tester to check for power at the outlet., or a lamp.

Write back or call if this doesn't solve your problem.


bullet gif Is this wiring diagram correct? Subject: A wiring diagram question

Hello Robert,
I was looking around to find some help on this wiring set up.
I hope you don't mind me asking you a question like this. Not sure if you accept emails regarding question on how to do.
I am wiring 2 lights with a switch at the end of the run.
Did I do the diagram correctly?
Any info would be greatly appreciated. I apologize if I bother you with this.
Looks like a winner to me
Just don't forget it is not ok to "bury" the splice box - it must be accessible in case of repair. Accessible means you cannot need to impact the building finish to get to it [above an acoustic tile grid ceiling is ok, above drywall is not]
Best regards,
Robert Wilber Electrical Contracting
Philadelphia License # 3516 16765
Visit www.wilberelectrical.com


bullet gif Is knob and tube wiring safe? My wife and I are thinking about purchasing our first home, a nice little twin built in 1954 - 3 BD, 1-1/2 Bath, with 2 car detached garage (with power). Yesterday we had the home inspection and there were a couple of electrical issues that caused some concerns:

(1)There was active knob & tube wiring on the basement ceiling in the boiler room, on the finished side ceiling and in the attic. The inspector warned me that knob & tube wiring was typically used in older houses, they are potentially a safety hazard and therefore they may render a house uninsurable. He recommended that we look into upgrading.

*Knob and tube was only original wiring method. You will often find parallel gas outlets in oldest installations [in case electricity fad went away!] No safety hazard in knob & tube. Only risk is that extreme age can lead to deterioration of conductor insulation at outlets. Uninsurable? News to me! New knob and tube extensions are still allowed under limited circumstances in the newest code - Article 394. Changes would not be an upgrade, in the true sense, but a modernization.

Boy, did I get this one wrong! I couldn't believe the inspector was right. I called six different insurance agencies. Hazardous or not, NOBODY will TOUCH a house with knob and tube wiring! No explanations!

(2)There were several non-grounded outlets throughout the home (which I assume have to do with the knob & tube wiring?)

*This is a problem? Look at your lamps, radios and television sets - Most don't have a ground prong, anyway. Polarization is the real issue. - Normal in older homes, actually it is a good sign [nobody has "fiddled" anything in ...]


bullet gif I did my own electrical repair. Is this right? From: "Franco"
To: "Robert Wilber Electric"
Sent: Saturday, March 12, 2005 11:15 PM
Subject: Re: saw your blog

Here is my question.
I have two wiring circuits of old 14/2 no ground wire. They are on 15 amp breakers.
The wiring circuits service all the ceiling lights in a 1500 sq ft house with an old plaster ceiling.
One circuit runs from the breaker directly into a wall cavity and into the ceiling.
The other ran from the breaker down into the crawl space under the house. It passed through a junction box that also fed some outlets. I took the outlets off of this circut and put them on new wire and their own breaker. The remainder of the light circuit then left that junction box and entered a wall cavity through a hole in the floor. It then presumeably entered the ceiling to service its lights.
Apparently some owner a while back ran 14/3 no ground from the breaker to this junction box. One hot serviced the outlets and one serviced the lights. Once I had the outlets completely on new 14/2 with ground, I now had an unused former "hot" but now dead in this old 14/3 wire (unattached in the breaker box and unattached in the junction box.
So to get rid of it I ran a new 14/2 with ground from the breaker to the junction box and joined it to the old lighting circuit 14/2 no ground wire. I took the ground from the new wire and screwed it to the junction box since it had nowhere to go. The old wire seems to be well stapled and when I removed the outlets I had to pry the staple off instead of pulling on the wire to pop them off. They were in very tight (in 50 year old wood). I don't see how this can be pulled through the ceiling to replace the wiring with new wire to all the lights (8 in five rooms!).
I read that once an old circut is changed, the whole circuit must be changed. I am retired and cannot afford to rip out plaster ceiling to find the old wire trail.
Can I just leave it as is, with the new wire joined to the old? It certainly seems safe enough without that dead former "hot" around.
Do I need to put that 14/3 old wire back?
Or you have any suggestions?

Hi Franco
... old circuits, no ground ... no problem!
I don't think an old owner ran the 14/3. I believe it was part of the original wiring. If you run a 3 wire and put the two hots on breakers on different legs of the transformer, then you share the neutral just like you share the neutral in the panel. The loads actually balance across the hots at the farthest common point and the neutral only carries the imbalance. This is only a problem when someone wrongly puts both hots on the same leg. Then you can destroy the neutral. [if you have 5 amps on one hot and six amps on the other hot, then the loads balance and the common neutral carries the imbalance, or 1 amp-put them both on the same leg, the neutral load is 11 amps, if you did it wrong and had 15 amps on each hot, the neutral loading would be 30 amps, and glow in the dark-ok?] [or the neutral opens-read my blog-Lights acting funny?]
What they had done was take two circuits out to the junction point in the basement and used the black for the lights and the red for the receptacles [or vice-versa], and used the now common white neutral to carry the imbalance of the load. This is normal, standard, legal practice.
By running the new cable to feed the outlets, you freed up the one hot and left the white in the three wire as a "dedicated" neutral. You could have left it like that even, and just capped off the extra wire on both ends. By running a new wire and eliminating the three wire, you have simply 'un-combined' the circuits, which is fine.
You say you connected the ground wire to the junction box, which is perfect [using a machine threaded screw and not a self-tapping coarse thread metal-thread screw, right?]... and proper connectors at all locations, right? ...even demolished the old conductor ... great! And stapled or fastened the new cable properly ... wonderful! And covered the box back up ...!
Change the whole circuit? Hogwash! Not necessary! Not mandated ANYWHERE in the codes I know. [Boy, would THAT make it easy to get extras, or what!]
Suggestions? Pat yourself on the back for a job well done, sit back and relax! Sounds like you're in great shape!
Robert Wilber Electrical Contracting
Philadelphia License 000575
visit www.wilberelectrical.com


bullet gif Can I do my own electrical repairs? I expect that if you need to ask, the answer is probably NO!
Electricity can be dangerous!
Electrical work done inproperly can create situations that cause electrocutions and fires!
... and people are always asking such basic questions that suggest they haven't done ANY research or study at all ... [read my Philadelphia electrician blog!]
All the dangers and risks aside, could I do brain surgery? Perhaps, with information, training, experience and support!
Can you fix your car [like the shop does] or put up a wall [like on those construction sites with new homes you drive past, not just fiddled together]?
Do you know garbage work when you see it? Are you stubborn enough to do it right even if it is a pain in the neck and you can see five ways to do it that " ... wouldn't be the right way, but it'll work" ... then get information and look for support so you can get educated, trained and experienced.
There is nothing more satisfying than doing it yourself. Ask any two year old!

It is unlawful for anyone except an individual licensed by the City of Philadelphia to install electrical equipment and wiring. The owner of any property wherein any such installation is discovered shall be issued a violation by the Department of Licenses and Inspections. The limited exceptions include replacing devices and fixtures at existing outlets.
Answer in February 2010 by Jim Miraglia of the Department of Licenses and Inspections.


bullet gif Voltage drop-off e-mail inquiry We have a gas stove that has electric temperature control. It is next to the refrigerator and is plugged into the same outlet. The stove was not holding the set temperature so when our dishwasher repair man was out to service our dishwasher we had him look at the stove. He measured the voltage at the outlet while the stove was on and several times a minute the voltage would drop off to near zero and rebound. He checked the other outlets in the kitchen and found the same drop. He also checked an outlet not on the same breaker and there was a drop but not as severe. What would cause this?
DT - 12/2004

I will try to make this simple. I don't know how much, if anything you know about electricity. Take a look at the panel picture below [courtesy of Eaton Cutler-Hammer] Electrical Panel Photo [It is not a great rendering, but the best I could find quickly]
In the center of the box on the left is a sort of black snake shape.
This is actually what you can see of a sheet of insulating material behind the bussbars, which are to the left and right of the black part, and have little bars that stick in from the left or right in alternating rows. Can you see that ok?
In this panel, there is no main breaker, so the feed conductors get connected to the bussbars with terminal lugs at the top of each bar. The neutral bar, where the neutral conductors connect, is on the right side of the panel [it has a sort of dark top and bottom].

The most common power provided, to all residences and many commercial locations consists of 120/240 volt single phase power. In the transformer on the pole, pad or underground, the high voltage is converted to 120/240 volts such that the potential difference between the two ends of the transformer winding is 240 volts. There are either two windings connected in series to accomplish this or one winding. If there are two, they are connected end to end. The center point of this winding is then connected to a terminal which is intentionally connected to ground. It is the neutral point on the winding. The purpose is to create a voltage relationship such that no point on a residential electrical system has a voltage potential of more than 150 volts to ground. You now effectively have two 120 volt transformers connected in series. This is useful to know, because the symptoms suggest that the neutral is not compromised. [An open neutral would provide odd, variable voltages as the complex series-resistance value of the system changed. That is a whole other subject!]

When you connect a load across the transformer winding, the full voltage [nominal 120 volts] is "dropped" across the load, you don't drop 110 volts and have, say 10 volts running around free looking for a place to go. The power consumed is a product of the current in amps pushed through the load and the voltage applied to push the current through the resistance. One watt is the amount of power consumed when one volt pushes one amp through one ohm of resistance. At 120 volts, a current of one amp suggests a resistance of 120 ohms, which would mean a power consumption of 120 watts. 120 volts, 60 watts, 1/2 amp, 60 ohms. And so on

If you connect two resistances in parallel, like two lamps on the same circuit, the voltage drop is the same 120 volts across each, but the individual current flow is a function of the resistance of the load. A 100 watt lamp has half the resistance of a fifty watt lamp, so twice the current flows through it. A thousand watt lamp would have 1/20th the resistance of a fifty watt lamp.
Now let's get to your problem! The voltage intermittently drops to zero ... and then goes back to normal. This suggests an automatic operation which is either opening the circuit intermittently, or dropping the resistance of some parallel "load" to zero ohms. I take it you are not tripping breakers and/or blowing fuses, since you didn't mention that as a symptom.

A snap around ammeter would be useful at this point. Unless you are properly trained in safety procedures, you need an electrician at this point, because it gets dangerous. What someone with the right training will probably do is take a voltage reading at the breakers to determine which "hot" leg has the trouble on it. Bear in mind that one test which would be high on the list of things to check is whether the problem is outside your house! After taking a reading to see if there is intermittent high current on either or both hot legs [but you didn't say your lights are acting up] one would test to check which leg it happens on. Turning off the main and taking a reading on the incoming lines would verify that it was an internal or external problem.

My best guess, without further information from these tests, is that there is some motor driven item trying to start which has a locked rotor. This would act like a direct connection from the hot to the neutral, causing the symptoms you indicate. It would also occur regularly as the thermal protector opened and closed, allowing an attempted restart and voltage drop. There are many other items which could cause this symptom, but I think you get the idea. One thing you might try, which doesn't require exposure to the hazards of an open panel, would be to take turns shutting breakers off one at a time and see which one "solves" the problem. Then go looking for things that are off and see if there is some item plugged in that eliminates the problem when unplugged.

Do NOT go rooting around in your panel.
It IS dangerous and electrocution is no joke.
You CAN get killed really easy.
Dropped the ball here!
Read my blog note about an open service entrance neutral from the end of February 2005! Fluctuating voltage levels can have more than one cause!


bullet gif Electrical Home Safety/Hazards


bullet gif GFCIs A ground fault circuit interrupter (GFCI) [downloadable GFI safety pdf] is an electrical device which protects personnel by detecting potentially hazardous ground faults and quickly disconnecting power from the circuit. Any electrical device used on a house wiring system can, under certain conditions, transmit a fatal amount of current. Currents between 100 and 200 milliamperes (0.1 ampere and 0.2 ampere) are fatal. Anything in the neighborhood of 10 milliamperes (0.01) is capable of producing painful to severe shock. Any current over 8 milliamperes (0.008) is considered potentially dangerous depending on the path the current takes, the amount of time exposed to the shock, and the physical condition of the person receiving the shock. A GFCI works by comparing the amount of current in the ungrounded (hot) conductor with the amount of current in the neutral conductor. If the current in the neutral conductor becomes different than the current in the hot conductor, the GFCI opens the circuit. A current difference as low as 4 milliamperes (0.004) to 6 milliamperes (0.006) activates the GFCI and interrupts the circuit. The fault condition must be cleared and the GFCI manually reset before power may be restored.

*According to the U.S. Consumer Products Safety Commission (CPSC) about 200 people die from electrocution each year.


bullet gif Helping shock victims The human body is a good conductor of electricity. Direct contact with electrical current can be fatal. While some electrical burns look minor, there still may be serious internal damage, especially to the heart, muscles, or brain. About 1,000 people die annually of electric shock in the United States. The outcome of an electric shock to an individual depends on the intensity of the voltage to which the person was exposed, the route of the current through the body, the victim's state of health, and the speed and adequacy of the treatment. Electric current can cause injury in three main ways: Cardiac arrest due to the electrical effect on the heart. Muscle, nerve, and tissue destruction from a current passing through the body. Thermal burns from contact with the electrical source. When someone suffers serious electrical shock, he or she may be knocked unconscious. If the victim is still in contact with the electrical current, immediately turn off the electrical power source. If you cannot disconnect the power source, try to separate the victim from the power source with a nonconductive object, such as a wood-handled broom. [FIBERGLASS IS BEST!] *According to the U.S. Consumer Products Safety Commission (CPSC) about 200 people die from electrocution each year.
The human body is a good conductor of electricity. Direct contact with electrical current can be fatal. While some electrical burns look minor, there still may be serious internal damage, especially to the heart, muscles, or brain. About 1,000 people die annually of electric shock in the United States. The outcome of an electric shock to an individual depends on the intensity of the voltage to which the person was exposed, the route of the current through the body, the victim's state of health, and the speed and adequacy of the treatment. Electric current can cause injury in three main ways: Cardiac arrest due to the electrical effect on the heart. Muscle, nerve, and tissue destruction from a current passing through the body. Thermal burns from contact with the electrical source. When someone suffers serious electrical shock, he or she may be knocked unconscious. If the victim is still in contact with the electrical current, immediately turn off the electrical power source. If you cannot disconnect the power source, try to separate the victim from the power source with a nonconductive object, such as a wood-handled broom. [FIBERGLASS IS BEST!]

IMPORTANT: Do not touch a victim that is still in contact with a power source; you could electrocute YOURSELF!


Have someone call for emergency medical assistance immediately.

CALL 911!
Administer first-aid, as appropriate.


PECo's Emergency Phone number is 1-800-841-4141


bullet gif Why do my light bulbs burn out so fast?
Quality control
Variations in unique state of materials in manufacturing process
Microscopic imperfections
Statistical probability

If you buy 10,000 60-watt lamps and turn them all on at the same time, every one of them will fail, literally, at some individually unique point in time.
No two will fail at exactly the same moment.
However, at some point in time, exactly half of the bulbs will have failed. Follow me?
When this has occurred, you have reached a point of mean lamp life, a value somewhat longer than the manufacturer will claim for mean lamp life.
... so if half the lamps burn out after 500 hours and the manufacturer says lamps last 450 hours, then you will experience that the lamps you buy usually last longer than the manufacturer claims. Good marketing. Not a reliable predictive value for the life of any individual lamp, however. that doesn't mean that all the lamps will not have burned out after 501 hours or that one won't burn out two minutes after you turn it on. It is not a point on a curve.
In a perfect situation where the lamp is never subjected to any temperature swing, vibration and/or voltage variance, the lamp would burn for 750 to 1000 hours before burning out. But because lamps are rarely used in this perfect situation, outside events and elements tend to excessively flex the filament and can eventually break it.
The lamps may be installed in a location commonly subject to some physical shock which damages them: vibration from being installed in a fan, hammering, extremely cold drafts like that from refrigeration equipment, overhead foot traffic .. in this case, try a rough service lamp.
The lamps may be subjected to voltages outside their service envelope: 115-volt rated lamps installed in an area where the utility is delivering 130 volts, extreme overvoltage and load imbalances caused by an open common neutral. Have the neutral problem fixed or try a lamp with a higher voltage rating.
If the problem only occurs in particular locations, it may also be the case that the lamps have too high a wattage rating for the fixture, causing heat buildup and early failure, or that the lamps are not seating properly, which also causes uneven heat buildup.
Otherwise, is it always the same socket that the lamp fails in first?
Are we talking about a massive difference in failure time?
If both these statements are true, the lamp socket possibly has a loose connection at a rivet and is contributing heat [if you can imagine that] to the lamp base, causing premature failure.


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