Hello,
Speaking of inspectors, I resemble that remark and have the State of California photo ID to prove it. Doing the things you did and asking the questions you ask you do not have a clue. You are a danger to self and others. You, your wife, dog or children may become the short circuit to ground or earth depending on where you “live”. Forget the hum and call a qualified electrician to repair that accident waiting to happen.
DT
I did my best to report what I FOUND in the wall, in the hope of receiving meaningful input, and it worked well. I appreciate and express gratitude for the advice. I ask questions because I do not know the answers, and I approach this forum with humility and respect. But.......I also know about forums and the importance of taking advice with a grain of salt.
Candidly, everyone (at least in the construction industry) has had their fill of arrogant sparkies. With all due respect to your photo card, your advice would have more integrity and value if it lacked the personal attack and provided information beyond "hire an electrician like me." If you have some, bring it on. Otherwise.........
Rosinante,
I think it is important to understand that if you have the return of any power connected to the chassis of equipment you have a danger to yourself and others.
Here is why: let’s take a Lamp. Any power into the lamp will go through the filament and return down the return "Neutral". if the neutral was to break open the power still goes through the lamp, however now the neutral return will rise to the voltage of the input because it is no longer "held down" with a connection to the board. If you have a 3 wire system then the chassis of the equipment is connected to earth. The equipment neutral return is separate so if it went open it will still rise to supply however it is not connected to your equipment chassis. You are protected with an earthed metal enclosure which is bonded to the same ground you are standing on!
If this happens to the chassis of your equipment any one touching the chassis will receive a shock from the supply trying to return to earth. I am a UK Elec engineer so I step back to those who work on your systems "US".
I don't think anyone is trying to bully you they are concerned for your well being.
Regards
M. Gregg
I think it is important to understand that if you have the return of any power connected to the chassis of equipment you have a danger to yourself and others.
Here is why: let’s take a Lamp. Any power into the lamp will go through the filament and return down the return "Neutral". if the neutral was to break open the power still goes through the lamp, however now the neutral return will rise to the voltage of the input because it is no longer "held down" with a connection to the board. If you have a 3 wire system then the chassis of the equipment is connected to earth. The equipment neutral return is separate so if it went open it will still rise to supply however it is not connected to your equipment chassis. You are protected with an earthed metal enclosure which is bonded to the same ground you are standing on!
If this happens to the chassis of your equipment any one touching the chassis will receive a shock from the supply trying to return to earth. I am a UK Elec engineer so I step back to those who work on your systems "US".
I don't think anyone is trying to bully you they are concerned for your well being.
Regards
M. Gregg
Hello,
Sparkie doesn’t like me much either. I am the guy that stands outside the door when he turns on the breaker. I have seen sparkie hanging limp on the utility pole. I do not want that to happen to you. Nothing personal.
Here is more information not yet discussed here. Codes have changed over the years, depending on the age of your home many of the branch circuits may only be 2 wire without a green or bare safety wire. Someone may have installed new 3 prong outlets with the safety connected to the white wire. The white wire and the black wire may even be crossed, who knows. Still 2 wire, grounding to a steel or copper (grounded) water pipe with a clamp connected to the U slot on a 3 prong outlet in kitchens and baths was added to the code.
Then along came 3 wire safety ground circuits everywhere. The most recent addition is the GFCI required at kitchens, baths, outdoor outlets within 6 feet of the ground and boathouses. The GFCI is the only 3 prong outlet allowed on an existing 2 wire circuit.
Someone in this thread spoke of the white wire not being grounded at the utility transformer. The white wire is required to be grounded to an earth ground at the main panel at your house not the transformer. That ground can be a water supply pipe, a driven rod in the ground or a grounding grid. To protect sparkie on the pole the transformer is not grounded. The transformer on the pole provides 2 hot phases with 240 AC volts between them. The grounded neutral is provided at your house.
Nothing personal, you do not know and learning the hard way hurts you, your wife, dog and children.
DT
No doubt you have the picture of what you have. Having had to correct a lost neutral you see how it's not unthinkable odds to happen again. The old 2-wire system is safe as long as the chassis of something doesn't get energized by a short, even if you lose the neutral, unless you are holding a radio built before 1950 that uses a hot chassis, non-transformer, PS. Best to revert all the outlets that were "fixed" until you can do the rewiring.
Lucky you with the hum... funny how things workout.
Lucky you with the hum... funny how things workout.
Thanks Gregg, and DT. I replaced the service panel on my last house, inclusive of ground rods, large conduit up the gable and a weatherhead, blah blah. That was done neatly and properly, and inspected. I was proud, and I learned stuff. I am still learning and the information you have provided is helpful.
I also appreciate your concern. I am not dismissing that. I've made my 53 trips around the Sun by (sometimes narrowly) avoiding mortal danger and I become more careful over time. I understand, to some degree, the neutral/ground connection at the main box, the loop in which electricity travels, past practices that code no longer allows, etc. This two-wire cabling in my home is going to be replaced by modern, proper, 12/2 w/ground. With all due respect (in this instance that phrase is a double-entendre), I will likely run this cable myself. I am not a reckless, cavalier, exposed-wire sort of guy. I will likely also install a GFCI at the start of each separate circuit, as these provide a nice additional protection.
I am glad for the discussion we have had in this thread, and glad this amp had a humming problem. I am not creating a dangerous condition, DT. I am addressing one. And again, I appreciate the information you ultimately offered.
I also appreciate your concern. I am not dismissing that. I've made my 53 trips around the Sun by (sometimes narrowly) avoiding mortal danger and I become more careful over time. I understand, to some degree, the neutral/ground connection at the main box, the loop in which electricity travels, past practices that code no longer allows, etc. This two-wire cabling in my home is going to be replaced by modern, proper, 12/2 w/ground. With all due respect (in this instance that phrase is a double-entendre), I will likely run this cable myself. I am not a reckless, cavalier, exposed-wire sort of guy. I will likely also install a GFCI at the start of each separate circuit, as these provide a nice additional protection.
I am glad for the discussion we have had in this thread, and glad this amp had a humming problem. I am not creating a dangerous condition, DT. I am addressing one. And again, I appreciate the information you ultimately offered.
That's what I am thinking. An open neutral is discovered, then an amplifier hums. Hmmmm........ Upon further investigation, it appears that at least one outlet circuit in my home is unsafe. Glad to know that. I needed a new project like I needed another hole in my head, but I also need to avoid electrical current to my body.
I just wonder if the outlets in my shower enclosure include this neutral/ground connection. I'm kidding, DT. I almost never use my hair dryer in the shower.
I had some of the same issues in my house in addition to nearly 100yr old knob and tube wiring on a circuit with a 20A breaker (not my doing) and comprised of wiring that appeared to be no more than 18ga, this circuit was beyond maxed out.. All of that wiring has since been professionally replaced (I "apprenticed" with a master electrician to do some of it) and that along with all of the rewiring I did on my own has been inspected by the city I live in.
Note that in bedroom outlet circuits the local code (and I believe NEC too - haven't checked) now makes provision for arc fault interrupters in the entrance panel to protect against things like frayed line cords and extension cords. Most breakers provide limited if any protection against this fault. Early AFIs seemed to be prone to nuisance trips IMLE, but current ones seem to be much improved..
The pole transformer neutral are all grounded at the pole and at each individual residence here in Eastern Ma. (Per local codes and power company practice - I've also physically checked, and asked the inspector when he was last here.) The low soil conductivity here mandates two ground rods approximately six feet apart, with water mains, entrance and other metal conduits, meter and panel all bonded by a dedicated grounding conductor.
Note that in bedroom outlet circuits the local code (and I believe NEC too - haven't checked) now makes provision for arc fault interrupters in the entrance panel to protect against things like frayed line cords and extension cords. Most breakers provide limited if any protection against this fault. Early AFIs seemed to be prone to nuisance trips IMLE, but current ones seem to be much improved..
The pole transformer neutral are all grounded at the pole and at each individual residence here in Eastern Ma. (Per local codes and power company practice - I've also physically checked, and asked the inspector when he was last here.) The low soil conductivity here mandates two ground rods approximately six feet apart, with water mains, entrance and other metal conduits, meter and panel all bonded by a dedicated grounding conductor.
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I worked for my local Labor department, and my office was physically surrounded by electrical inspectors. In doing my labor research, I became aware of the fairly sharp distinction between inside and outside electricians and systems. "Outside" installations fall also outside the inspection and code requirements, training is very different and there is consequently no love lost between the two groups.
Just as an example, when I changed the service box on my last house, this involved having the power guy come out and disconnect, then reconnect, the service cables. After disconnecting, he left two hot and one neutral cables hanging from a gable end and only about seven feet above another roof surface he knew I would be working from. These cables were HOT, unfused and covered with a pathetic and thin wrapping of electrical tape. He stood there and cut those hot cables with lineman's pliers. I asked him about all this, and he just shrugged his shoulders and acted like it was no big deal. Hypothetically, had I jammed the ends of those two hot cables together, the cables would have drawn as much amperage as that transformer could deliver, and the cables would have no doubt exploded. Let's just say I was unimpressed.
Just as an example, when I changed the service box on my last house, this involved having the power guy come out and disconnect, then reconnect, the service cables. After disconnecting, he left two hot and one neutral cables hanging from a gable end and only about seven feet above another roof surface he knew I would be working from. These cables were HOT, unfused and covered with a pathetic and thin wrapping of electrical tape. He stood there and cut those hot cables with lineman's pliers. I asked him about all this, and he just shrugged his shoulders and acted like it was no big deal. Hypothetically, had I jammed the ends of those two hot cables together, the cables would have drawn as much amperage as that transformer could deliver, and the cables would have no doubt exploded. Let's just say I was unimpressed.
Last I checked, circuit breakers with GFI protection were spendy. I was told that an entire circuit is protected if a GFCI outlet is installed at the front of that circuit.
You can also get a cheaper GFI circuit breaker and install it in the panel for the entire circuit.
A power cable story. I worked as maintenance electrician in a factory that was doing some equipment replacement. I was assured the power to a 3-phase motor drive controll was disconnected. I used a pair of line pliers to cut through the cable. It exploded like a shotgun and burned big holes through the cutter. Of course the breaker tripped and I didn't feel a thing except I couldn't hear anything for a few minutes.
Ooops, Spendy. Translated... expensive.
I installed a GFI breaker for a bath circuit because, if I recall, I discovered one that was cheaper than an outlet. At least, I think, maybe, it was cheaper.... I'll shut up, now.
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Ouch! We had lock out, tag out procedures for such work at the large semiconductor ATE company I used to work for to prevent such accidents.. Up to 100A/480V/3 phase at 50 or 60Hz plus every other variant used anywhere on the planet. Powerful stuff...
I participated in the modernization of an international airport, which included more transformers and switch gear than you could shake a stick at. My role was labor compliance. We did not have a sense of humor about lockout/tagout violations. Some people were ejected from the project and not allowed to return, in spite of vigorous attempts by the IBEW to reinstate the workers throught the grievance process. Though I am a Labor guy, I was proud of airport management for this. Perhaps it takes a little longer and costs a little more, but we're not going to pay for these improvements with the lives of childrens' daddies. Period.
Ouch! We had lock out, tag out procedures for such work at the large semiconductor ATE company I used to work for to prevent such accidents.. Up to 100A/480V/3 phase at 50 or 60Hz plus every other variant used anywhere on the planet. Powerful stuff...
Lock and Tag is a legal requirement in Elec @ work regs UK. Even so people do try to short cut sometimes with terrible consequencies!
Long time ago I pulled a fuse "to isolate a circuit" while up a ladder and the carrier disintegrated leaving me holding the fuse with the incomming live tail still attached, could not put it down could not turn the buss section off couldn't get down the ladder. 415v 500A nice!
This was on a main PLC production line TPM. My work is much more diverse these days. I also inspect H&S as a side issue!
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Hello,
Much depends on local jurisdictions. The Public Utility in my end of the world does not want ground on their pole. The idea is to prevent their lineman from becoming a short circuit to ground. The Public Utility is not governed by the same building codes (electrical) as your home.
Regardless of what happens on the pole the typical local electrical code (most US codes are modeled from NFPA 70, or the National Electrical Code) requires a ground at the service entrance.
If there is a voltage difference between your plumbing in the floor and your neutral or safety ground there is a problem. That NEC we are talking about requires bonding connections between the ground, neutral, plumbing, steel structure and anything conductive to prevent you from becoming the short circuit to ground.
DT
Yup. Plumbing pipe needs to be grounded, according to my local inspectors.
You guys heard about the fella who traded his 40 year-old wife in for two twenty year-olds? Few weeks later he's back with his old wife. When asked why he reversed his previous decision, he said "I discovered I'm not wired for 220's."
You guys heard about the fella who traded his 40 year-old wife in for two twenty year-olds? Few weeks later he's back with his old wife. When asked why he reversed his previous decision, he said "I discovered I'm not wired for 220's."
True for GFCI/GFI, but last time I checked the arc fault interrupter was only available for installation in the panel. It combines the functionality of a conventional circuit breaker with arc fault detection. It's required in new construction around here and in updates as well.
I've found panel based GFCI to be rather expensive, but plan to install some on kitchen circuits because my wife does not like decora style outlets and that is the form factor for standard outlet mounted GFCIs.
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