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Hopefully this is the right forum to post in. At any rate, we are in the middle of a kitchen remodel. I came home Thursday after the electrician had been there all day to find:


1. My Kinivo HDMI switch no longer works.

2. All of the HDMI ports on my tv no longer work.

3. One of our bedrooms that has a remote for the ceiling fan and light, had the light and fan stuck "on". Even flipping the breaker and then turning it back on resulted in the light and fan coming right back on. They replaced the in wall receiver and it works again.


I know very little about electrical goings-on. My general contractor and electrician think the electricity company is to blame. I have never in my life had a damaging power surge. Is it just coincidence that the first one happened while the electrician was there? He said that just turning the power on and off as they were setting up the sockets and can lights wouldn't damage electronics.


Any insight would greatly be appreciated. Thanks!
 

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He ran out of spots in the neutral/ground buss in the load panel, loosened some to double up the #14's.


Neutral currents had no place to go other than through the low level inputs.


You shoulda used a multiport outlet surge protector.


jn
 

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jneutron touched upon it being neutral related,


This is fascinating, and often mis-understood effect.

I would essentially guarantee .... that a neutral was opened up under load, thus excessive voltage greater than 120v was placed across some items for a period of time. It wouldn't necessarily have occurred at the panel, it could easily (and most likely) have occurred at a junction box, or a receptacle or switch box whereby joints were being made. It doesn't matter where it happened, they did it.


Surge from the power company .... yeap, right ...



The contractor is liable, it would only take a brief moment for this to occur, and often occurs when an electrician is making up a neutral joint (adding another wire, etc.), and the return path to the panel is opened up, thereby the low impedance path is gone, yet another route is availed to the via the other phase.


Now, for a brief period, there's series connected loads instead of the typical parallel connection. The least robust device gets cooked, the reason being the entire 240v is now dropped between the two loads. The smaller the load, the larger the voltage dropped across it. The larger the load, the smaller the voltage dropped across it. Hence, the damage occurs to the small, modest devices.


Then, the neutral joint is made up the manner the electrician intended, and the circuit is back to normal, however the damage is already done.



I'd be glad to detail this further if need be.



I hope this helps.
 

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Quote:
Originally Posted by FOH  /t/1469496/technical-help-badly-needed#post_23240610


I'd be glad to detail this further if need be.
Cool..I've always wanted to know what that white wire was there for..
and that black one, why is it called hot when it's cool to the touch??



I wasn't thinking entire house float, just a few breakers worth.


I figured that maybe the OP had both legs of his panel powering his equipment, and if the electrician opened neutrals to the romex feeding the system, that the Y line filters would show the imbalance to the HDMI's. That's why I recommended a multiport device, it would bond all the equipment input grounds as common to the equipment third pin.


Had a kitchen reno about 7 years ago, the electricians did run out of buss positions for neutrals and grounds, so had to double up some. So it was my best guess.


jn
 

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The white wire is the return current wire, or "NEUTRAL" wire, which is connected to the ground bus in the electrical panel.


The black wire is the ungrounded side of the circuit, which means its voltage can kill if you touch it while some part of your body is somehow contacting something grounded at the same time you touch it; this is why it is called "HOT".


The third wire, which can be bare or green also is connected to the same ground bus in the panel, but it carries no current unless there is a short-circuit in the device being powered by the circuit.


A "GROUND-FAULT INTERRUPTER" socket is now required by most electrical codes in bathrooms, kitchens, and other areas where the body is more likely to be inadvertently grounded and coming in contact with some "HOT' part of the device might be possible. Plumbing and running water are usually grounded, as is most concrete, so touching them and somehow contacting a hot circuit can be deadly.


The GFI can detect a very small current in the third wire, which could be through your body, and shut off the circuit in milliseconds, before you are dead. Also, if some inappropriate current leakage in some powered device takes place between the hot wire and 3rd wire, the GFI will shut off the circuit and its visible button will pop out to show that the fault has occurred. The GFI can also detect a small difference between the currents in the black and white wires, which will always be equal unless there is a circuit fault.


In a normal 110 volt circuit, the current to the device being powered goes through the black and white wires equally to pass through the device. That is a normal circuit. The third wire never has any current unless there is a fault in the device or a person's body inadvertently gets across the circuit.


In the US, a 220 volt circuit has two 'HOT" wires and a 3rd wire. Both "HOT" wires carry the current, and each one of them is 110 volts with respect to ground, but because their AC voltages are 180 degrees out of phase with each other the voltage from one "HOT" wire to the other is 220 volts RMS. There is no "neutral" wire in a 220V circuit, just 2 hot wires and a ground wire.


Installing a GFI at the point where your audio equipment plugs in can protect you against internal shorts in the gear that could cause metal parts of the equipment to become "hot" and be hazardous. A GFI is a good idea. It will kick off if a piece of equipment has an internal short or current leakage (which is usually not obvious).


Circuit breakers offer no protection against electrocution. They only prevent wiring from overheating and causing fires. They shut off the circuit only when the current flow in the wires exceeds a safe limit
 

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Hey there commsysman. Long time no talk. How you been? Hope all is well.


While I like you info and certainly agree, I was um, joking about that white and black wire thingy.. Hope you didn't post because of my joke, I did put some emoticons there. Course, it is always worth repeating every so often for those who don't work with electricity.


Ah, I'm not sure it all applies for those outside the US however..I only know this side of the pond.


jn
 

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Quote:
The GFI can detect a very small current in the third wire,

No it can't. Your understanding of GFCI is flawed....and you spent two paragraphs on it



A GFCI monitors the current flowing through hot an neutral, if there is an imbalance the assumption that a ground fault has occurred trips the circuit open.
Quote:
While I like you info and certainly agree,

...not as smart as you'd like us to believe...
 

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^ ^ ^

Correct




Visualize ... a circuit with a hot going out, and the neutral coming back.


Stripped to it's essence, ...if anything goes out, and doesn't come back, the circuit opens up. That's GFI protection.


Back OT


The OP's scenario is fascinating. Many electricians acknowledge open neutral issues, but often fail to understand how the damage occurs. Just takes a brief moment, then they come down off the ladder to measure the receptacle(s), everything appears fine ... the damage already occurred to the connected items.
 

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Quote:
Originally Posted by SAM64  /t/1469496/technical-help-badly-needed#post_23244467


No it can't. Your understanding of GFCI is flawed....and you spent two paragraphs on it



A GFCI monitors the current flowing through hot an neutral, if there is an imbalance the assumption that a ground fault has occurred trips the circuit open.

...not as smart as you'd like us to believe...

You got me. Egg on my face big time.


sigh, I scanned through it too fast...



I'll remember you...newmann!!!



(good catch)


jn
 

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Quote:
Originally Posted by jneutron  /t/1469496/technical-help-badly-needed#post_23244777

Quote:
Originally Posted by SAM64  /t/1469496/technical-help-badly-needed#post_23244467


No it can't. Your understanding of GFCI is flawed....and you spent two paragraphs on it



A GFCI monitors the current flowing through hot an neutral, if there is an imbalance the assumption that a ground fault has occurred trips the circuit open.

...not as smart as you'd like us to believe...

You got me. Egg on my face big time.


sigh, I scanned through it too fast...



I'll remember you...newmann!!!



(good catch)

Some day JN you may learn to not try to school well-educated, well-experienced people who work with a given technology hands on, day after day...
 

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Quote:
Originally Posted by FOH  /t/1469496/technical-help-badly-needed#post_23244639



The OP's scenario is fascinating. Many electricians acknowledge open neutral issues, but often fail to understand how the damage occurs. Just takes a brief moment, then they come down off the ladder to measure the receptacle(s), everything appears fine ... the damage already occurred to the connected items.

In some over simplified theory of equipment operation there is an infinite impedance between the power line connections and any of the active or passive circuits in the AV equipment. When you disconnect neutral, but retain the connection to hot, current stops flowing through the primary side of the power supply, the equipment stops working and that is that. You reconnect neutral, current resumes flowing and the equipment powers up without damage. That is life in the ideal world. Let me know when you find that ideal world!


In the real world there are leakage impedances between the power line connections and every circuit in all of the AV equipment. What the leakage impedances actually are varies all over the map. On a bad day disconnecting neutral allows the reference for some active circuits to float as high as the hot power line voltage - about 120 volts AC plus any spikes, etc. If the signal connections to those circuits are connected to safety ground or neutral or something like them, and they do not have adequate over voltage/over current protection, then some component parts may be permanently damaged.
 

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Quote:
Originally Posted by arnyk  /t/1469496/technical-help-badly-needed#post_23244839


Some day JN you may learn to not try to school well-educated, well-experienced people who work with a given technology hands on, day after day...

You very much need to listen to your own words there arny..


jn
 

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Quote:
Originally Posted by commsysman  /t/1469496/technical-help-badly-needed#post_23243692



In the US, a 220 volt circuit has two 'HOT" wires and a 3rd wire. Both "HOT" wires carry the current, and each one of them is 110 volts with respect to ground, but because their AC voltages are 180 degrees out of phase with each other the voltage from one "HOT" wire to the other is 220 volts RMS. There is no "neutral" wire in a 220V circuit, just 2 hot wires and a ground wire.

In the US we also have 240 volt circuits with two hot wires, a neutral wire, and a safety ground wire.

http://www.nojolt.com/Understanding_240_volt_circuits.shtml


...

"I previously mentioned "straight" 240 volt appliances, but there is another class of 240 volt equipment; some appliances (such as clothes dryers and ranges) use 240 volt current to power their main function (drying clothes or cooking food) but use 120 volt current to power accessories such as the clock on your stove or the light inside the oven, or the digital readout on your dryer controls. That is why some 240 volt circuits have four wires:


1) A black wire which is often known as the "hot" wire, which carries the current in to the fixture.

2) Another "hot" wire which is red, which also carries current in to the fixture.

3) A white wire called the neutral which completes the electrical circuit for the 120 volt accessories only.

4) A bare copper wire called the ground, the sole function of which is to enhance user safety.


At one time, the code allowed for one insulated wire to function as both ground and neutral in 120 / 240 volt combo circuits, but now all such circuits must use the 4 wire scheme. This is why your new dryer (or electric range) might have 4 prongs on its plug and your old dryer receptacle only has 3 holes. In which case article 250.140 of the 2005 N.E.C. (National Electric Code) allows for the "pigtail" (the cord and plug assembly) to be changed to match the old 3 wire receptacle as long as certain conditions are met. The National Electric Code allows that, but your local code might not, so check first, or even better yet make a deal with the appliance dealer

"
 

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Regarding post #12


Arny, up there in post #4 is what occurred, I'm unsure what you intended. Is the above post of yours separate from the scenario discussed?


Sorry, at a loss.
 

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Quote:
Originally Posted by arnyk  /t/1469496/technical-help-badly-needed#post_23244890


In some over simplified theory of equipment operation there is an infinite impedance between the power line connections and any of the active or passive circuits in the AV equipment. When you disconnect neutral, but retain the connection to hot, current stops flowing through the primary side of the power supply, the equipment stops working and that is that. You reconnect neutral, current resumes flowing and the equipment powers up without damage. That is life in the ideal world. Let me know when you find that ideal world!
Here we go again arny. Please refer to qualified professionals, you are going to get somebody hurt with bad advice.


Lost neutrals are extremely dangerous. When one is lost, the potentials at the branches will indeed depend on the load split between phases.


The condition can also occur if the user has used both legs to power a interconnected system and neutral/ground are disconnected at the panel.


Seriously, your statement is dangerous. Please refer to a qualified electrician.


jn
 

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Quote:
Originally Posted by jneutron  /t/1469496/technical-help-badly-needed#post_23244937

Quote:
Originally Posted by arnyk  /t/1469496/technical-help-badly-needed#post_23244890


In some over simplified theory of equipment operation there is an infinite impedance between the power line connections and any of the active or passive circuits in the AV equipment. When you disconnect neutral, but retain the connection to hot, current stops flowing through the primary side of the power supply, the equipment stops working and that is that. You reconnect neutral, current resumes flowing and the equipment powers up without damage. That is life in the ideal world. Let me know when you find that ideal world!
Quote:
Originally Posted by arny - same post 



In the real world there are leakage impedances between the power line connections and every circuit in all of the AV equipment. What the leakage impedances actually are varies all over the map. On a bad day disconnecting neutral allows the reference for some active circuits to float as high as the hot power line voltage - about 120 volts AC plus any spikes, etc. If the signal connections to those circuits are connected to safety ground or neutral or something like them, and they do not have adequate over voltage/over current protection, then some component parts may be permanently damaged

Just for future reference JN what you did is called out of context quoting and is considered to be intellectually dishonest in most of the western world. Perhaps you were raised in a community where the young people were not warned about such things in high school or middle school?
 

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Quote:
Originally Posted by arnyk  /t/1469496/technical-help-badly-needed#post_23245098

Silly goose. You'll pull any stunt in an attempt to save face...


What I copied was the dangerous concept you tossed out. Your second paragraph did nothing to correct that concept. Go back and read it again...he lost a fan switch as well. And quite honestly, If the overhead is powered via the same branch as some of the wall outlet equipment, that's another problem. A blown breaker for an outlet load shouldn't can the lights.


Lost neutrals are dangerous. When a system is powered by both phases, and the neutral is lost to that system, the resultant voltage on the lowest load will go up, sometimes to maximum of 220. I believe that is what fried the OP's HDMI's, as the chassis filters pulled the equipment ground of one too high for the HDMI's.


You always try some shtick or another to walk around your glaring errors...


jn.


ps. your odd "rebuttal/attack" post was weird, you messed up the quotes..
 

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Quote:
Originally Posted by SAM64  /t/1469496/technical-help-badly-needed#post_23245252

Quote:
Some discuss because they can. Others attack because they cannot.

poignant

Indeed, one starts a paragraph out saying: "In some over simplified theory of equipment operation there is an infinite impedance between the power line connections and any of the active or passive circuits in the AV equipment." and this is criticized as if it is a guide for system design and practical operation.


What's unclear about "over-simplified"? Apparently for some, quite a bit!
 
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