EC&M forensic casebook, OCT 2014

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don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
The Forensic Casebook article in the October 2014 issue of EC&M suggests that we need a redundant bonding conductor because the installer could not tell the difference between blue and green and connect the blue conductor to the motor case grounding point. Where do we draw the line? The incident would not have occurred had the EGC been correctly terminated.
Here is a link to the article, but you do have to register to read it:
http://ecmweb.com/accidents-investigations/case-improperly-terminated-motor
 

big john

Senior Member
Location
Portland, ME
That was actually a big part of what turned me off from that magazine. There were a number of those Forensic Casebook stories that I thought came to fantastically inappropriate conclusions because of their need to try and affix blame for an injury.

They can go on about how qualified the electrician was, but if the coloration of the green and blue conductors was similar enough to allow this mistake to have been made, then the electrician exercised fantastically poor judgement by trying to guess at their appropriate function. As the phase conductors were isolated it would not have been difficult to ring one out the EGC to ground and determine appropriate function.

You can't legislate solutions to account for extremely poor decision making.
 

kwired

Electron manager
Location
NE Nebraska
Redundant bonding method would have prevented the accident that happened.

Many other possible procedures could have been made mandatory that may have helped as well.

Something as simple as having the person that disconnected this before being the one that reconnects it after may have prevented this accident.

Redundant bonding methods are not bullet proof but are a design issue that can have some benefit, they are not required by NEC either. Until such an incident like this happens, nobody thinks of such things unless they have seen similar incidents before, or they come from a place that uses such redundant bonding but maybe never knew why - they just did it because that was what they did there.


BTW I have not been all that impressed with EC&M for something like 15 years now. I once sent them a photo of a code violation and a short story to go with it for their code violations section - they turned the whole story inside out when they published it and it had little accuracy as to pertaining to what actually was done at the installation. I guess I didn't tell a hot enough story to publish, instead I told it like it was:slaphead:
 
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PetrosA

Senior Member
I find it sad that this kind of workaround has to be done at all.

We know for a fact that approximately 10% of human males suffer from some type of color deficient vision. We know that most electricians are male. We know that green perception, being made up of blue and yellow, affects multiple type of vision deficiencies. Yet, we here in the US vehemently refuse to require grounding conductors to be marked as they are in almost any other country using a green and yellow striped pattern. The code allows for it, but doesn't require it. It would be a simple thing to change that.

Some green pigments used to identify ground conductors are so poor that I've even seen guys who weren't color blind to any degree have trouble identifying them in poorly lit conditions or under certain types of light with output deficiencies in the range needed to differentiate a weak green from black. A striped ground would eliminate this problem in close to 100% of the cases.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I find it sad that this kind of workaround has to be done at all.

We know for a fact that approximately 10% of human males suffer from some type of color deficient vision. We know that most electricians are male. We know that green perception, being made up of blue and yellow, affects multiple type of vision deficiencies. Yet, we here in the US vehemently refuse to require grounding conductors to be marked as they are in almost any other country using a green and yellow striped pattern. The code allows for it, but doesn't require it. It would be a simple thing to change that.

Some green pigments used to identify ground conductors are so poor that I've even seen guys who weren't color blind to any degree have trouble identifying them in poorly lit conditions or under certain types of light with output deficiencies in the range needed to differentiate a weak green from black. A striped ground would eliminate this problem in close to 100% of the cases.
That would, IMO, be a reasonable requirement and could likely be implemented with little increase in expense.
 

Nom Deplume

Senior Member
Location
USA
I had something that EC&M published from me. It was a tip on doing something, I forget.
I was supposed to get $50, but after they published it they asked for my SS# so they could send me a 1099.
I told them to keep their money.

Their mag as turned into a pamphlet.
 
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mbrooke

Batteries Included
Location
United States
Occupation
Technician
That was actually a big part of what turned me off from that magazine. There were a number of those Forensic Casebook stories that I thought came to fantastically inappropriate conclusions because of their need to try and affix blame for an injury.

They can go on about how qualified the electrician was, but if the coloration of the green and blue conductors was similar enough to allow this mistake to have been made, then the electrician exercised fantastically poor judgement by trying to guess at their appropriate function. As the phase conductors were isolated it would not have been difficult to ring one out the EGC to ground and determine appropriate function.

You can't legislate solutions to account for extremely poor decision making.


Im going to be honest. EC&M isn't really geared for electricans. Its more for maintenance workers and EE light reading to a lesser degree. Heck Id say its just a step over popular mechanics...
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Im going to be honest. EC&M isn't really geared for electricans. Its more for maintenance workers and EE light reading to a lesser degree. Heck Id say its just a step over popular mechanics...
The original EC&M when it was not free and Joe McPartland had a big part in was the best electrical magazine I ever saw. Unfortunately that magazine has been gone for a long time.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
The original EC&M when it was not free and Joe McPartland had a big part in was the best electrical magazine I ever saw. Unfortunately that magazine has been gone for a long time.


I agree. Even up until 2006 it was not bad, I liked it. But the last 3-4 years have not been my cup of tea.
 
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