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 Post subject: Thru Panel Voltage Detectors
PostPosted: Tue May 31, 2011 9:26 am 
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Joined: Tue May 31, 2011 9:03 am
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Location: Davenport
If you use thru panel voltage detectors in your electrical safety program, I just finished a technical description of how they work. A user of a voltage detector needs to understand how a power system (high resistance ground, isolated ground systems, etc.) influence the functionality of these devices. Correct installation within an electrical enclosure also improves the reliability of the voltage testing equipment. Benefits include mechanical LOTO without voltage exposure and reduce PPE requirements for electrical LOTO.
Here is the link:
[url="http://graceport.com/assets/files/Application%20Notes/VoltageVison%20How%20it%20works.pdf"]http://graceport.com/assets/files/Application%20Notes/VoltageVison%20How%20it%20works.pdf[/url]


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PostPosted: Tue May 31, 2011 6:20 pm 
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Location: Connecticut
Is there a question here...? :confused: Looks like a sales pitch to me.


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PostPosted: Tue May 31, 2011 8:18 pm 
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One client I worked with I think installed about 1500 of them between the plant and the field.. They seem to work, but they also had to install "clarification" stickers on why every combination of the lights was on on certain sites or in certain applications (single phase, 3 phase, etc).. They seem to work.


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PostPosted: Wed Jun 01, 2011 5:55 am 
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Location: Charlotte, NC
How do you know if there is no voltage present or if the device has failed? I don't see how this device can meet the requirements of verification in 70E 120.1(5).


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PostPosted: Wed Jun 01, 2011 6:49 am 
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Location: Spartanburg, South Carolina
Zog wrote:
How do you know if there is no voltage present or if the device has failed? I don't see how this device can meet the requirements of verification in 70E 120.1(5).

Note 2 of the attachment says that it does not meet LOTO requirements.
Quote:
[2] The traditional "Live-Dead-Live" LOTO safety procedure with a voltmeter remains intact. These comments only describe the added safety benefits if a VI is employed in addition to existing LOTO procedure.

I'm not sure why a panel mounted VI would be wanted instead of a panel mounted voltmeter.


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PostPosted: Wed Jun 01, 2011 8:20 am 
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jghrist wrote:
Note 2 of the attachment says that it does not meet LOTO requirements.


So exactly how does one get to the claimed PPE reduction for LOTO?


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PostPosted: Wed Jun 01, 2011 9:36 am 
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Location: Connecticut
Looks like this is nothing more than a power "idot light" indicator. Nice to look at but not much use.

As far as the claim to reduce PPE:

1) It doesn't reduce the short circuit fault current at the starter or device.
2) It's not a replacement for OHSA LOTO procedures that require to test that all sources of energy are removed.
3) It doesn't prevent someone from locking out the wrong or mislabeled device. (see #2 above)
4) It doesn't replace a volt meter.
5) If anything it can give someone an excuse to short cut established LOTO proceedures.

I put this device in the same class as single phase power factor correction gizmos that claim to save money on your residental electric bill.

Anyone interested in buying swamp land in Fla? :D


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PostPosted: Wed Jun 01, 2011 10:26 am 
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Location: Charlotte, NC
Same "ad" was posted in MH forum a few weeks back, I asked same questions and never got a response.


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PostPosted: Wed Jun 01, 2011 6:10 pm 
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The Senior Electrical Person for one client that I have seen with these lights basically trained all of their operators and if they are doing a lock out all of the lights need to be on before they start, and all of them have to be off when the breaker is open.. If either of the above is not entirely true than an electrician has to do the verification... They only have them installed on low voltage (480 volt or less)...
As for PPE, their MCCs are around 5 cal/cm2 or less. Their PPE matrix has a minimum of FRC to 8 cal/cm2, leather gloves, hard hat, safety glasses, ear plugs, etc... And they know and practice to stand on the hinge side and look away.


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PostPosted: Mon Jun 06, 2011 7:34 am 
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Joined: Wed Jun 02, 2010 12:59 pm
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Location: Milwaukee WI
Another offering, "DeadEasy"

I was just reviewing an MCC drawing from a colleague located in Australia.

There is a product called "DeadEasy" (amusing name) used in Australia.

http://www.redbusbar.com/shop/Voltage-Indicator-LEDs/

Appears to be more than an "idiot light".
Dual color LEDs, Green = isolated, Red = live or problem, off = no power.

I have asked for more detail about usage and experience.

In Australia, they use MCCs with rotary through door disconnects ala IEC. My engineering experience, I will never use a rotary through door as first choice. Lever action is a much better solution.

Not a product pitch, I work for an OEM with global customers. Always interesting to see practices outside of USA & North America.


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PostPosted: Mon Jun 06, 2011 9:42 am 
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I agree with AB... I've seen several situation where IEC rotary disconnects have failed to open all 3 phases. I'm not a fan of IEC equipment. IMO it's cheap junk. Adds new meaning to the phrase..."Test before you touch".


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PostPosted: Mon Jun 06, 2011 8:08 pm 
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I agree.. Rotary handles through the doors, from my experience, have had a tendancy to wear more than lever action style handles. They would never be my first recommendation to keep..


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