voltage drop at receptacle

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ldbelec

Member
An electrical inspector in my area is now checking voltage drop at receptacles in dwelling units. He is using a meter that puts a 20 amp load at the receptacle and measures voltage drop.
This has caused an uproar in our area and the inspector will not listen to reason. My arguement is that he is putting a 20 amp load on a 15 amp receptacle. In other words past its rated load. Also that voltage drop is not an enforcable code requirement. I'm hoping that if reads some unbiased opinions he will realize his whole theory and method of doing this test will convince him that this test makes no sense. One of his arguements is that with a low voltage reading the wire will heat up and cause a fire. I can't seem to convince him that the breaker will see 20 amps regardless of the voltage. Has anybody heard of an inspector performing this test?
 

websparky

Senior Member
Location
Cleveland, Ohio
Re: voltage drop at receptacle

Tell him he has no enforcement authority for voltage drop.

If he argues, ask him to show you where it is written.

Also tell him to stop stressing your wiring system!

[ December 16, 2004, 05:33 PM: Message edited by: websparky ]
 

jimwalker

Senior Member
Location
TAMPA FLORIDA
Re: voltage drop at receptacle

Where did they find that idiot ? He is overstepping his authority and he himself is violating the code by placing a known 20 amp load on a 15 amp receptacle.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Re: voltage drop at receptacle

If he is failing people for not passing his VD test, I would object.

If he is just testing for his own edification, I could care less.

If he is not failing anyone, whats the worst that could happen? Its not going to hurt the wiring unless he leaves the load on for a long time (like hours) and if he did that the breaker would trip.

And if he happens to find a 20V drop in your wiring, he may well be doing you a favor by finding a potentially big problem for you.
 

websparky

Senior Member
Location
Cleveland, Ohio
Re: voltage drop at receptacle

Now Jim,

I don't call inexperienced electricians "idiots".

Maybe you could drop the "idiots" when it comes to inexperienced inspectors?

OK??
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: voltage drop at receptacle

In most areas the inspector must either pass the job or provide a written notice of failure with a code section cited.

Unless there is a local amendment the inspector can not fail a job for voltage drop.

Bob
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: voltage drop at receptacle

Originally posted by ldbelec:
One of his arguements is that with a low voltage reading the wire will heat up and cause a fire.
Ask him to show you that with ohms law. :D
 

jimwalker

Senior Member
Location
TAMPA FLORIDA
Re: voltage drop at receptacle

Ok your right ,but this inexperienced inspector has far to much time on his hands.If he was causing me trouble with my job i would take whatever steps i could to get him removed from a job he should not be doing.Or send him to school before he inspects any more jobs .Is that better ?
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Re: voltage drop at receptacle

His tester is looking all the way to the transformer, so I would ask him to use his pull as a representative of the AHJ and try to get the POCO to increase their conductor size, otherwise all of you may be using # 8 for your branch circuit wiring in most dwelling units. :D

Roger
 

ldbelec

Member
Re: voltage drop at receptacle

By the way this is westlake ohio. Any local inspectors out there willing to give an opinion?
 

hank1

Member
Re: voltage drop at receptacle

In one local jurisdiction the insp. requires a 5% max vd through their amendments, and they check. But they test the circuit with the load that it is rated for, 12 amp for 15 amp circuit. I think it is wrong to fail someone by putting a 20 amp simulated load on a 15 amp circuit. Ideal makes a gfci/afci tester that also checks for vd at 12,15 and 20 amps simulated load.
sample test at panel gfci in basement 15 amp
12 amps - 1.6
15 amps - 2.0
20 amps - 2.7 Hank
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Re: voltage drop at receptacle

Originally posted by ldbelec:
8 volts-but that is not the point-testing at 20 amps is the point
Just cause they are 15A outlets does not mean its necessarily not a 20A circuit.

I don't see a really big problem with this new ordnance, as long as everyone has to abide by the same rules.

IMO its no less offensive then requiring AFCIs for no real good reason other than to sell a product that no one would otherwise buy.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: voltage drop at receptacle

I am curious as to how he is measuring the voltage at the panel at the same moment he is measuring voltage at the receptacle. The code?s (unenforceable) statement on this topic relates to voltage drop along a feeder and along a branch circuit. You need to measure voltage at two points, in order to get a voltage drop.
 

jimwalker

Senior Member
Location
TAMPA FLORIDA
Re: voltage drop at receptacle

With no load he would read the max available.Sort of like long test leads.Then apply load and would get a lower reading.Is this guy testing every outlet ? How many inspections does he get done in a day ,2 ?
 

jtester

Senior Member
Location
Las Cruces N.M.
Re: voltage drop at receptacle

From a practical point of view, the entire circuit has 15 or 20 amps on it, distributed from the first receptacle to the last. It seems unrealistic to pick the last receptacle and put anything more than 180va, unless it was dedicated for something.
Another thought, New Mexico has recognized that 3% feeder or branch circuit, and 5% overall voltage drops are difficult to maintain with todays standard practices. They have chosen to permit 5% and 7% respectively.
Jim T
 
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