Electrical system testing procedures around the USA

Specific Inspection Topics Electrical Inspections
1

[FONT=Arial]Electrical System Testing

Questions:

  1. What is a grounding point(s) test?

[FONT=Arial]2. What is an electrical outlet load test? [/FONT]
[FONT=Arial][/FONT]
[FONT=Arial][FONT=Arial]3. What is an infrared main panel load test?[/FONT][/FONT]
[FONT=Arial][FONT=Arial][/FONT][/FONT]
[FONT=Arial][FONT=Arial]Are these services covered by any regulations, and do they include specific qualifications, such as licensing?[/FONT][/FONT][/FONT]

2

Joe,

That is an excellent question! This would make a great discussion.

[FONT=Arial]*1. What is a grounding point(s) test?

*I’ve performed installation and testing in the past for military and commercial systems grounds. For our purposes we used the two and/or three pole ground testing methods at the grounding electrode, with the grounding electrode conductor obviously removed from the grounding electrode. A good article discussing this can be found at: [/FONT][size=2]http://ecmweb.com/mag/electric_putting_theory_practice/

[/size][FONT=Arial][FONT=Arial]2. What is an electrical outlet load test?
[/FONT][/FONT][FONT=Arial][FONT=Arial][FONT=Arial]3. What is an infrared main panel load test?[/FONT][/FONT][/FONT][FONT=Arial][FONT=Arial][FONT=Arial]

I’ve never had a need to perform load tests at the at the actual electrical outlet and obviously have not had a need to perform an infrared test at the main panel. I have, in the past, performed load testing for the main feeds, load testing at switching equipment and also at distribution panels. These have all required specialized, and actually calibrated, load banks and test equipment.

[/FONT][/FONT][/FONT]***[FONT=Arial][FONT=Arial][FONT=Arial]Are these services covered by any regulations, and do they include specific qualifications, such as licensing?[/FONT][/FONT][/FONT]***[FONT=Arial][FONT=Arial][FONT=Arial]

I know the NEC will certainly set the standards as to system performance requirements, i.e. a GE reading of <25 Ohms, etc. I know here in Texas these tests, if not performed by the structures owner or employee (in other words if contracted for) do fall under the purview of a licensed electrician to perform. No doubt this is something that we as HI’s should not be performing unless we are licensed as an electrician.

I’ve actually seen HI’s advertising these services on their WEB site. I found it interesting that with the thermal camera explosion I’ve also seen one HI advertise that they will load an entire panel to 80% capacity, let it cook and then perform a thermal scan for problems. I would certainly like to here from others who may perform, or have performed, any type of residential testing of these types. What I would be interested in is:

  1. What method are you using to test the residential system ground point?
  2. Are you testing loads at individual outlets and how? There appears to be some contention as to the accuracy and usefulness of the some commonly used test equipment such as the Suretest Circuit Analyzer.
  3. Has anyone actually performed load testing of residential panels and how was this accomplished and what equipment are you using?

It is, no doubt, a very interesting subject!
[/FONT][/FONT][/FONT]

3

I would be interested in the method used to load the system. Is it by a portable source, or some other separately derived system?

4

Hi Joe,

Load testing I performed in the past were just calibrated resistive banks attached generally at feeds and outputs. A lot of it was reliability tests for inverters on backup battery banks. Rarely was there ever a need to test at individual branch circuits of any type and then it was only single branch circuits.

It would be interesting to know how someone is loading an entire residential electrical panel for a thermal scan.

5

You too, eh? (or in the US: “You too, huh?”) Was soon to be a question of mine on the IR thread!!!

6

Hey Brian,

You are pretty knowledgeable in this area and maybe can provide me an education. I performed some of the tests mentioned above but that was many, many moons ago. Since then we have progressed to much more reliable and better designed equipment which makes it almost unnecessary to do it. About the only thing I ever see these days are ground tests for building ring grounds, lightning halo grounds, etc. Generally then it is more a connectivity test more than anything. Equipment grounds are usually only tested when soils or conditions are suspected to be a problem. I have not heard of load testing being done at all anymore as manufacturers perform it and guarantee conditions.

About the only ground testing I see being performed anymore are ground radials for communications systems but that is a whole different creature in itself!

Do you see any of this going on anymore? If so how have you seen them test it? I’m a knowledge freak and grounding has always been an interesting subject for me.