Electrical Wiring in the Home/usb outlet wiring


QUESTION: Hello. I purchased a usb charging outlet. It has black, white and green wires extending from the box. The ideal place for this outlet appears to be in a circuit. There are two wire bundles, each with black, white, ground extending from the wall box. Both sets are attached to the outlet being replaced. It's a non-GFCI box. I tried capping off one set of b/w/g and attaching the usb box to the other set of wires but that disabled other outlets.

1) Would it be safe to attach both black, both white, and both ground wires to the usb outlet.

2) Would that potentially damage any devices to be powered through the usb outlet or damage the usb outlet?

Thank  you!

ANSWER: David you are not adding right?  Just replacing/upgrading?

If you are not adding it should be just fine, by installing in parallel like the original.

The only thing that bothers me with these outlets is surges and other fairly normal, in this day and age... but A PROBLEM

If you don't have a whole house surge protector or something in FRONT of any USB 5 volt circuit, [it could provide some protection in the outlet itself,  but I bet it is not adequate.

It not as clean but I would prefer a UPS of some sort, and one with a USB charging port.

These USB outlets are convenient,  but the surges and other issues are often overlooked.

If you are planning to charge a bunch of stuff at this outlet I would look to see if the outlet provides any line to neutral protection  L-N  .

It will fit technically just like any other outlet,  but surges can come from coffee makers and other devices ON THE SAME CIRCUIT INTERNALLY   most are not aware of that

So you can do this as a normal install should be fine as far as amps so on,   but these damn spikes and electronics don't mix,  that is why you need suppression in front of ANY USB   and computers, phones chargers  electronics,       

I have a lamp with a USB port on it,   never use it,   and I have tons of protection,  I use both UPS and rack mount voltage regulators   with internal protection Line to Neutral not ground,  

SO the outlet could work,  but you MUST KNOW what else is ON the circuit and what protection you have in front of electronic gear    

If it is just raw circuit,  I would say go another route, now some of these USB outlets have protection but the physical limitations tell me not enough.

A whole house filter I would say go for it,  knowing the other loads   but if not I would use it sparingly and carefully,   shoot me a note to my e-mail if you need more info, but the outlet would not be wired incorrectly as a replacement.

---------- FOLLOW-UP ----------

QUESTION: Mr. Babbit,

Thank you for the very complete answer.  Yes, replacing, not adding.  Much of your answer is over my head but one point I believe to have understood is that surges could happen on this circuit that might damage my devices.  They're too expensive to risk.  I am going to do my due diligence and check this USB outlet to determine if there's any surge protection built in.

Would it be safer if the USB outlet were installed in a box that has only one set of wires b/w/g?  That is, no other electronics (blender, waffle iron, hairdryer) one the same circuit?

Phones, iPads and other devices come with outlet adapter plugs but no warnings about charging on multiple outlet circuits.  Your answer has me a little concerned about charging devices on multi-outlet circuits might be risky.  A little confused...

Thanks again!


hey Dave and it gets more complex,    the issue is complex and technical it would take a book to get started,    

Here is the problem    with all this stuff going electronic so fast,   the need for CLEAN POWER,  AND SAFE POWER  ALONG WITH ENVIRONMENTAL NUTS who have maybe the right heart but no concept of what really pollutes

just for a second,     the electric car, the hybrid  so on,    wonderful idea   but we have to charge the batteries   they are not a self contained circuit or ecosystem.

By the time you figure the belching smoke from coal fired plants,  the belching smoke it took to build batteries  to build the car,  to NOW deliver a charge to the batteries,   the smoke is four times more with each car than if the car were simply gas driven,   Except FOR ONE LITTLE FACTOR  efficiency  an electric motor can be rated as high as mid 90 in eff.,  where an internal combustion engine is at best 40-50%

Then add in all the power hungry chargers  useless power strips,   and all this energy is needed now one amp at a time,    25 years ago, it was a few amps at a time but not even close to the demand now days      because now we have a billion devices   back then a million   rough example  

Dave,   As far as trying to prevent surges from the HARD SIDE   the 115 volt side of things,  there is no box no anything I Know of  to suppress surges     

With this type of outlet  which probably cost you a pretty large amount of cash,   with NOTHING IN FRONT   you are charging your devices at the same risk level as your can opener [assuming it is electric]  loose a can opener   ten bucks   

Lose a charger phone  or multiple devices   not only the  cost of the device but the friggin hassle to get everything reprogrammed, deal with warranties and fuss with it all   is just a nightmare,    

If you have a bunch of USB devices as most of us do,   you have to protect those circuits,  I am getting a million questions on this,

Your utility sends spikes down your line probably every day,  most are switching transients that come from adjusting load at substations,    most are harmless    but the first time a piece of switchgear malfunctions  and your lights go black, on, black on,  the HARD SIDE is given a huge but short ZOLT

It weakens motor windings which are literally hundreds of times larger than any electronic device  the biggest circuit no bigger than a fraction of a strand of hair,    

Here is my advice for now,    I would charge stuff through as small as you can get UPS  they act like and sometimes are isolation      important    isolation transformer,     which induces voltage to the secondary   but NOT CURRENT     

It is a huge buffer for spikes   but the UPS itself could end up trash,    this is serious problem that not many understand  

A $99.00 dollar small UPS  will charge a lot of USB  devices at the same time putting a firewall between your devices and the rest of the world    but they are clunky and not nice and clean like this wall outlet,    I Personally would NEVER install one,   just due to the risk,    I would rather sacrifice some old small laptop  for a charging center  might not even boot up,   just one that has live usb     there are a million ways to go about this,  but sooner or later     everyone will fill the pinch      I see it growing   and I get the issues more and more and more

I have no nice an clean and easy analogy for this,  need to work on one,   but forget the USB tied to your main power       

I would rather sacrifice decor in favor of this high dollar stuff,   which means you will have to hide it,  the logistics are never easy   the logistics of a USB tied to an outlet are very desirable,     but your devices are exposed like taking the charger   taking some jumpers   alligator clipped jumpers  and clamping them on to some overhead line,    

MOST OF THE TIME it would be fine,    but when a car hits a telephone pole and takes out a large transformer  surges go everywhere    

Utilities switch loads  so if the north side of happy land is demanding more power,   they switch some from the south side  when they do  a spike or surge or high freq signal is tossed down the power lines,  some dissipate, some fry the guts out of everyones TV , but they say nothing about this potential hazard   I have seen some in the tiny tiny small print from a utility  but think about it        who reads that ?

I don't want to make you paranoid and afraid to plug anything  into anything,   

MOST OF THE TIME it is fine,  but it is getting to be more frequent and much more often.

When the guy built or designed the can opener  the last thing he or she was concerned about was someones cell phone,     what the hell does a can opener have to due with a cell phone,  


Nothing back a few decades ago,    now we have USB outlets on our regular outlets and that is a ploy to sell you redundancy and convenience.   How clever  here is a usb port for the whole family      

I have not found one from any manufacturer that has enough protection on the usb side,  to make me happy,    now if they used an  isolating transformer that would be one thing,   but here is a link to popular mechanics take:


then check this out,   now your cell phone has it's own insurance category   see a pattern ?


For now I would suggest if you can and if has not been wired they should take it back  

As you have nothing to protect the AC side, you have nothing to protect the DC supplied by the USB     and some devices will charge  some require more power      Chargers range from .01 amps to 10 amps and more,       most people are not EEs   yet we have to charge this stuff,   

take a look at one sample charger in your home  and find the amperage or current rating  probably something like  5 volts dc 1.0 amps  to make it simple      then find the current rating of the possible new wall outlet,    is it large enough   or more than 1 amp?

They can build those at whatever power rating they want and most layman are not going to understand, so hanging a USB replicator is possibly out of the question depending on the power available from this new outlet,      

I know confusing      and you have the thing,    but the best I can do is tell you   I have a whole house protector,  a power conditioning center,  then individual protection in the form of UPS  boxes to cover computers,  high dollar amps,  so on,       one I have the AC covered  now I go down to individual devices,   

believe me  I have the same need for charging  all this  just happen to be a high voltage guy and a low voltage guy,   not even the TOP Expert in the World can tell you where a lightning bolt might dissipate

They know in general   but for sure  no way,    this is an up and coming profit center for the same buttheads that steal from us everyday    

If you have no problems with your charging situation   hang loose,  I cannot tell you if the outlet although it seems like the most powerful way to go USB    not in reality   it depends on the output power of the outlet in USB or DC  outlet,   these outlets are often very large  they need to rectify the voltage to dc  lower it to 5 volts     and all that stuff has to jammed into a wall outlet with no chance of cooling,    

Read up on the subject,  maybe install it, and try something    something that is maybe older or simple to replace and see how it goes,      

ONE outlet unless you some kind of port replicator  is fairly useless anyway  and they aint going to put  5-10 amps in that little device although again it is much larger than normal outlets,    

you can use my personal email   it is much less cumbersome than going back through allexperts,     and a hand for about.com     they simply provide this service for nothing,    I like that   so I help out     it is the best way I know to give someone a hand or prevent a bad situation,      but to get to me is all    about.com wants to do,   very cool    they have no problem if I put my personal infor  out there   which aint real smart    of me,  but it does go faster  
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Will Babbitt


Electrical issues of all types, wiring, control, appliances, components, specialty in Electric MOTOR or APPARATUS trouble shooting, electric motors, electrical problems, single phase, three phase, DC, capacitors, elevator MG-Sets, modifications, reverse engineering, VFD Drives, single to three phase convertors. Repair of most any electrical/mechanical/electronic apparatus, OEM, AC, DC, Industrial Applications, Three phase, single phase failure mode, determining the root cause of the equipment failure BEFORE failure repeats, Antique appliances, electric motors, fans, ceiling fans, base mount fans, poor equipment performance, Modifications, habitual failures, vibration, redesign, obsolete issues, collectible items restored, rewinding. Owner of EMR Repair Inc www.emrrepair.com More information on electric motors, under Engineering/Motors Ask about any electrical or mechanical problems in the home, office, or even at your work. B2B or business to business CONSULTING I can do but it would be a much more complex issue, that would require a significant amount of time. repair@mearservice.com from there we can discuss and begin work on about anything. Industrial electric motors, controls, troubleshooting, vibration, alignment, any type of industrial or commercial electric/electrcical equipment For the home owner, renter, apartment if you have odd things going on, describe to me, photos are normally very helpful, appliances, heating and air conditioning issues, light switches, installation, DIY PROJECTS FOR THOSE NOT EDUCATED IN ELECTRICAL, we can do some things, but for safety and sanity reasons, I may refer you to a local electrician, and help you find one, help you with pricing and even speak directly with anyone you hire if you have issues,


Over thirty years with a major repair and sales company, VP of Operations, and former owner of my own specialty repair shops, MEAR Services local to Kansas City Missouri EMR Repair Inc., located in Kansas City Missouri, 2014 sold both businesses to JCI Industries, Lee's Summit Missouri wbabbitt@jciind.com Evaluation and repair of electrical/mechanical apparatus. Electrical and mechanical repairs, trouble shooting including, vibration and balance issues. About.com provides this service, and the huge costs to provide help on about any subject. They provide the servers, the people to vet the experts, costs that would be the same as operating a good sized business, They should be appreciated for what they do, the huge costs and the great help they provide for free, Electric motor questions, can be answered here but there is a dedicated category that has other experts to help and add to a solution. Other common questions, are noises in the walls, breakers tripping, devices not starting or shutting down for no apparent reason, smoke alarms buzzing, thermostat change outs, or sizing wire or needing information for a new project, but anything can be resolved, anything, with enough effort and patience, DIY, with electrical is possible, but in most cases the use of a simple ohm meter or volt meter is needed, they can be purchased at any hardware store for a few bucks. If you have smoke, or smell smoke, don't be writing me, call 911 the Fire Department has no problem looking for smoke smells, better then spraying water on a blazing fire. DO NOT GET CAUGHT INVESTIGATING AND TRAPPED IN A BASEMENT LOOKING FOR A BLOWER FAILING< As to the tip jar, it is up to you, it is appreciated, every expert spends out of pocket that I know, we spend on IP time, computer wear, printing documents, books, and of course our time, but if we prevent a $400 service call, we did well,

Former IBEW, EASA, IEEE, UL, ..............


10 plus years, various Technical Schools, followed by Industrial College Credit and non Credit Courses, electronics courses, experience in most any electrical apparatus, electric motors and generators, AC OR DC, fractional to above 5000HP, other electrical apparatus, slip rings, sleeve [plain] bearings, lubrication, identification-no data plate, control components, service and sales. I have continued night schools for decades, the list is extensive. I have been in the business of repairing most anything with wires or mechanical parts for decades, I have some helpful hints and directions you won't have to dig up. Or hopefully not have to pay a huge service call invoice to find.

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