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Author Topic: Test your grounds regularly!  (Read 26247 times)

Jonathan Johnson

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Test your grounds regularly!
« on: November 22, 2014, 02:56:47 PM »

We test our smoke detectors.

Our cars do a self-test on the airbags every time we start the engine. We make sure the brake pads and tires aren't worn out.

We inspect fall arrest equipment regularly.

We inspect fire extinguishers annually.

We make sure our first-aid kits are kept stocked.

We test or inspect other safety equipment that we use, on a regular basis.

But we never test the safety grounds in our electrical systems, until there is an unfortunate incident.

Because the safety ground does not normally carry current, a failure of the system will not be obvious until someone receives a shock, is injured or killed, or there is equipment or property damage.

Since the National Electrical Code, electrical inspectors, and audio/video/computer engineers recognize the importance and safety of proper grounding, doesn't it stand to reason that it's a safety device that should be inspected and tested on a regular basis, just like every other safety device we use? But yet we treat it as "set-it-and-forget-it."

Test those grounds as if your life depends on it, because it does.
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Stop confusing the issue with facts and logic!

Jonathan Johnson

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Re: Test your grounds regularly!
« Reply #1 on: November 22, 2014, 02:58:58 PM »

Hmm. I suppose that means I just gave myself a job, checking the grounds of all the receptacles on my farm.
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James Wright

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Re: Test your grounds regularly!
« Reply #2 on: November 22, 2014, 04:18:25 PM »

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Steve M Smith

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Re: Test your grounds regularly!
« Reply #3 on: November 22, 2014, 05:17:06 PM »

We do in the UK.

http://en.wikipedia.org/wiki/Portable_appliance_testing

Well, some of us do.  Everything which comes into our factory has been tested but I have never turned up at a venue with a band or PA and been asked by the owner if any equipment has been tested and it's not a legal requirement.

And it really annoys me that it gets referred to as a PAT test when the T in PAT is for test.  That's as annoying as PCB board!


Steve.
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Mike Sokol

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Re: Test your grounds regularly!
« Reply #4 on: November 22, 2014, 07:21:47 PM »

Well, some of us do.  Everything which comes into our factory has been tested but I have never turned up at a venue with a band or PA and been asked by the owner if any equipment has been tested and it's not a legal requirement.

And it really annoys me that it gets referred to as a PAT test when the T in PAT is for test.  That's as annoying as PCB board!


Steve.
Or SPL level?  :o
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Mike Sokol
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Ray Aberle

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Re: Test your grounds regularly!
« Reply #5 on: November 22, 2014, 09:25:37 PM »

Or SPL level?  :o
From the Department of Repetitive Redundancy Department
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Stephen Swaffer

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Re: Test your grounds regularly!
« Reply #6 on: November 22, 2014, 10:37:08 PM »


Test those grounds as if your life depends on it, because it does.

Easy to say and hard to disagree with-but IMO much harder to effectively do.  I don't consider a 3 light tester or a NCVT adequate for "safety" testing-they are good diagnostic tools and can be effective in assuring that everything is as we expect it to be-but if I am putting myself in harms way, I will use something more robust as a primary test-opening a breaker/switch that I can verify disconnects, or any of a dozen other things.

To play devils advocate, I could place a 100mA fuse in an EGC and it would test fine all day long-until an incident happens.  True, a very unlikely scenario, but a corroded or loose connection could create the same issue.  I am for safety testing-but I detest testing that merely makes me (or management) feel good.  Any suggestions on a ground test that would be reasonably robust, while still being convenient?
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Mike Sokol

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Re: Test your grounds regularly!
« Reply #7 on: November 22, 2014, 11:15:23 PM »

Easy to say and hard to disagree with-but IMO much harder to effectively do.  I don't consider a 3 light tester or a NCVT adequate for "safety" testing-they are good diagnostic tools and can be effective in assuring that everything is as we expect it to be-but if I am putting myself in harms way, I will use something more robust as a primary test-opening a breaker/switch that I can verify disconnects, or any of a dozen other things.

To play devils advocate, I could place a 100mA fuse in an EGC and it would test fine all day long-until an incident happens.  True, a very unlikely scenario, but a corroded or loose connection could create the same issue.  I am for safety testing-but I detest testing that merely makes me (or management) feel good.  Any suggestions on a ground test that would be reasonably robust, while still being convenient?

An INSP-3 or SureTest Analyzer would do this test nicely, but unfortunately won't find an RPBG without a secondary test such as measuring for EGC voltage referenced to a known external ground using a wire run to the service panel's ground or a NCVT which references earth ground through your own body. These ground impedance testers cost about $300 which is too expensive for casual usage but certainly affordable for a certified inspection. 

In all cases the test gear is only as good as the person doing the test. So training a technician what to look for and how to interpret the results is just as important as having the right (calibrated) gear.
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Debbie Dunkley

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Re: Test your grounds regularly!
« Reply #8 on: November 22, 2014, 11:30:54 PM »

From the Department of Repetitive Redundancy Department
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Tuna Fish

Here in the U.S. folks say "cod fish" too.  In the UK folks just say "cod".
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Lyle Williams

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Re: Test your grounds regularly!
« Reply #9 on: November 23, 2014, 01:23:04 AM »

PAT testing verifies that RCD/GFCI works.  On site "trip button" testing of RCD/GFCI tells you that ground isn't open circuit.  Not foolproof though.
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ProSoundWeb Community

Re: Test your grounds regularly!
« Reply #9 on: November 23, 2014, 01:23:04 AM »


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