Voltage Drop Question

Originally Posted By: wdecker
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Inspected a brand new home in a new development. Electrical service was lateral, 200 AMP Siemans panel, neat, clean, nicely grounded, AFCI breakers for the bedrooms, etc. All wire gauges OK.


BUT...

All of the exterior GFCI outlets (5) registered as having between a 6% and 19.4% voltage drop under 12 amp load, per the Sure Test meter.

As well, all the outlets in the living room, along one wall (3) tested as having voltage drops as well.

No other problems. I tested every outlet. All had less than 5% voltage drop, even at 15 amps.

I actually opened one of the living room recepticles to check and see if they wired it with the punch-down instead of the screws, bit it was properly screwed down.

I reported it as a voltage drop greater that 5% at 12 amps and recommended evaluation by a licensed and insured contractor (which the developer probably won't like, but I don't work for him, so there!).

Any ideas what could cause this. I speculate that there could be a loose splice at some junction box somewhere. Anyone?


--
Will Decker
Decker Home Services
Skokie, IL 60076
wjd@DeckerHomeServices.com

Originally Posted By: gbeaumont
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Hi Will,


It could be a poor connection somewhere, but also maybe due to the run length of that circuit.

Regards

Gerry


--
Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education
gbeaumont@inspectiondepot.com

"Education is a journey, not a destination"

Originally Posted By: rcooke
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Poor connection some where.


I am not a lover of the receptacles that have the push in hole.


Screws make for tighter connection



Roy Cooke Sr.


http://Royshomeinspection.com

Originally Posted By: wdecker
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The living room outlets and about 1/2 of the outside ones are on the same wall as the main service panel.



Will Decker


Decker Home Services


Skokie, IL 60076


wjd@DeckerHomeServices.com

Originally Posted By: Greg Fretwell
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It may be as simple as a backstabbed receptacle that the weather got to.


Originally Posted By: wdecker
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I can see this on the exteior recepticles, but the interior ones?


Of course, all the interior ones with this problem are on an outside wall.

In any case, 'Recommend evaluation by a licnesed and insured electrical contractor.'


--
Will Decker
Decker Home Services
Skokie, IL 60076
wjd@DeckerHomeServices.com

Originally Posted By: rcooke
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wdecker wrote:


In any case, 'Recommend evaluation by a licnesed and insured electrical contractor.'


Good answer we are inspectors not trouble shooters .

I do not put in the part about insured again I am not a baby sitter.
I also do not know if they have a brother who is qualified.

I am a sparky and that is what I say .
Then I move on to do my inspection


--
Roy Cooke Sr.

http://Royshomeinspection.com

Originally Posted By: wdecker
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Agreed, Roy,


I just wanted to know, for my own purposes. Probably a loos connection somewhere, but it isn't my job to open all the junction boxes and find out.

I put 'insured' in the recommendation because there are may who call themselves electricians in this area who aren't. If they hire one of these 'travellers' and something goes wrong, hey, that's their call.

In Illinois, there is no licensing of electricians (by the state, as with plumbers). One can call themselves 'licensed' if they register with the county (some counties require technical tests) and prove GL insurance. So, around here, licnesed and insured are pretty much linked.

But, hey. We can only recommend, not require.

They pay me money for my recommendations. If they choose to not follow then, that's their business.


--
Will Decker
Decker Home Services
Skokie, IL 60076
wjd@DeckerHomeServices.com

Originally Posted By: rbennett
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Will


You ask for an idea or a guess as to where the drop was

Here is mine -- the neutral wire in the panel

Reason - people working too fast and quality goes down hill

Too bad that the builder did not find this problem before he paid the electrical contractor.




If I am paid for "invasive" testing to find the drop so sparkie can fix it, I plug in a "heat gun" as a load. It pulls about 14 amps depending on how I adjust the air flow. A few checks with the DVM will find where the voltage drop is.

Remember, somewhere there is a 50 to 100 watt heat source. This can do damage. Also as the heat goes up so does the resistance thus more heat.

You might smell or see smoke where the drop is also

Sparkie now knows where he messed up. The home owner could be using the same heat gun outside to take some paint off something that he got at a garage sale.

I like invasive inspecting

Have a good day

RLB


Originally Posted By: jjackson
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Will


Isn’t testing voltage drop beyond the scope of an inspection?



jj

Originally Posted By: rbennett
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John


My thoughts are that testing of any type is beyond the scope of a visual inspection - HVAC Temp - voltage drop - H2O pressure - moisture % - level - square - outlet check with tester - tape measure - IR imaging - etc..

All the above requires the use of test equipment. Some very Hi $$ 's

Then we get into the english word meaning area -

Be it testing or inspecting it comes down to a service that we provide for a fee. 4 point insurance inspections don't cost as much as a full home inspection with all the "inspection" equipment

RLB


Originally Posted By: wdecker
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We are allowed to go beyond the minimum standards of practice. It is called value added service.


Aren't we supposed to be the 'World's Elite Home Inspectors'.


--
Will Decker
Decker Home Services
Skokie, IL 60076
wjd@DeckerHomeServices.com

Originally Posted By: Greg Fretwell
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I notice you said H2O pressure, do you test that under a “load” too. Static water pressure doesn’t mean much if it drops 20% when you flush a toilet. That is analogous to voltage drop.


Originally Posted By: wdecker
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Greg;


I don't know if you were referring to me, but this is how (and why) I test water pressure (especially in a new home).

I put a gauge on an outside sillcock at the beginning of the inspection.

During the inspection, I run the dishwasher, fluch toilets and turn on faucets (usually many times and fact, for the faucets).

If I see much more than a 60lb pressure on the gauge (it retains the highest reading) and the static reading is very much lower that the hight reading, it is indicative of bad chambers and, I have found in my experience, small leaks.

Sure, it ain't fool proof, but it gives me a reason to 'Recommend evaluation by a licensed and insured plumber'. Of the 12 such situations I have done this on (they had such questionable readings) 11 times, the plumber found some leak or other problem (usually small leaks in the sweated joints.

You have to remember that around here, developers usually hire non-licensed guys (some of whom are really good) and some of these don't do too good a job.

New home inspections. I have NEVER run into one that didn't have at least 2 or 3 small, stupid mistakes that left unchecked, would couse a REAL big problem, later on.


--
Will Decker
Decker Home Services
Skokie, IL 60076
wjd@DeckerHomeServices.com

Originally Posted By: rdawes
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I do voltage drop measurements on all inspections but I don’t write them up unless they hit 10% or more. I find high drops on more new homes than old. Probably the back stabbed outlets but it could be nicked wires, a bad connection in a J box, or a long run of #14 wire. 125 ft of # 14 will account for about a 5% drop at 15 amps. They now have outlets that you can back stab and then tighen a screw the secures an internal clamp to have a secure connection. A good compromise between speed of backstabbing and good connections.


Originally Posted By: Greg Fretwell
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Will It would be handy if your guage saved the low reading too. That would allow you to see pressure drop when water was being used. If the pipes are clogged with scale that could be a pretty low number. That is when you get scalded in the shower. I can’t imagine how it can get much higher than static.


Was that a typo?


Originally Posted By: wdecker
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Nope, Greg.


I usually see a static of 50 - 55 in this area, but have seen bounces as high as 75 on those pressures. I also check the pressure when I have the upstairs shower and the basement wash tun running at the same time for the low pressure reading.

Hope this helps.


--
Will Decker
Decker Home Services
Skokie, IL 60076
wjd@DeckerHomeServices.com

Originally Posted By: Greg Fretwell
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I suspect the “bounce” is water hammer effect. The low pressure is the one that frustrates the customer.


Originally Posted By: wdecker
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But hammer ain’t good either.



Should be called out.


--
Will Decker
Decker Home Services
Skokie, IL 60076
wjd@DeckerHomeServices.com

Originally Posted By: Greg Fretwell
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I suppose this is old news for everyone but the fix for water hammer may be as simple as turning the water off and draining the system to get the air back in the buffers. Over time it gets dissolved into the water and they become water slugged