EC&M Forensic Case Book Article

[Greg1707]

I just received the June 2016 issue of EC&M magazine. There is an article titled: "The Case of the Computer Room Fire." In brief, a fire broke out in a spare bedroom that was being used as a home office.

The room contained several electronic devices. The condo was built in the early 2000s. The forensic investigator concluded that the fire may have been caused by the absence of an EGC in the circuit and receptacle.

Has anyone else read this article? I found it interesting.

 

[Greg1707]

Using Home Computer Equipment with two prong plug can lead to a fire.

Using Home Computer Equipment with two prong plug can lead to a fire.

No one responded to my post. Let me restate. Using home computer equipment without an EGC or a two prong plug can cause a fire? That is the summary of the article.

http://ecmweb.com/accidents-investigations/case-computer-room-fire

 

[mgookin]

Incompetent investigator.

That fire did not start inside the box or inside the receptacle. Look at the smoke pattern on the face of the receptacle and look at the power strips and tell me where the fire started.

 

[Sierrasparky]

Another false and misleading investigation.

No ground- what malarkey , its AC cable and approved for ground.
Who knows if those outlets were self grounding. Who knows if the receptacle made firm contact with the box( no fiber washer)

How come the box shown has no paint or drywall on it!

Have you read the comments by someone who claims to be in the know. What crap!
The insurance company was just looking for a potential deep pocket but did not find one in the appliance so went after the original contractor. What about the inspector. Inspection never revealed a open ground!

Personally I don't see how he is liable this many years later.


This is one bad investigation. :rant::rant::rant::rant::rant::rant: :happysad:





Juts a Note:

I moved my desk chair and accidentally pinched the USB cable I used for data transfer for my cell Phone. Well after some time is wore through and shorted. It melted and caused a smell. If I did not notice it would have gone POOF. My fault , what are we supposed to do have USB AFCI devices. Stuff happens that are not always the fault of a manufacturer or contractor. People cause things themselves too.

 

[Sierrasparky]

On a second look at that picture-

Does that AC cable look like from the 2000's.
Those conductors look like they are TW?

 

[don_resqcapt19]

They didn't really say that the lack of the EGC was the cause of the fire. They said they though it was, but did not investigate that issue as after the missing EGC was discovered their client was dropped from the suit and they did not do any additional investigation.

They are implying that there could have been high leakage current that had no where to go because of the missing EGC. I am not sure I agree.

Even if the circuit would have had an EGC, I am not sure it would have helped.

 

[hbiss]

I was going to start a topic on the same thing after reading that story.

Does that AC cable look like from the 2000's.
Those conductors look like they are TW?

I can't remember when it changed from TW to THHN but I can tell you that AC cable has had a bonding strip since before the 60's.

No ground- what malarkey , its AC cable and approved for ground.
Who knows if those outlets were self grounding. Who knows if the receptacle made firm contact with the box( no fiber washer)

Correct. No mention was even made as to whether the receptacles were self grounding. The author concludes that the ground screw on the yoke was required to be connected with a pigtail to the box which leads me to believe a lack of understanding on his part.

I'll put money on a cheap power strip/surge protector that had it's MOVs self destruct. Seen them shoot sparks several times.

I wonder if there was a laptop with NiMh batteries?

-Hal

 

[user 100]

I can't remember when it changed from TW to THHN but I can tell you that AC cable has had a bonding strip since before the 60's.

-Hal

I know that nm made the switch from tw to thhn (or 90c insulation) in the 1980s, but don't know when ac cable made the switch/ or if the 1980s change applied to all cables or just nm.:?

 

[tkb]

EC&M magazine has become a pamphlet for advertising and the articles aren't very good.
This article was written by someone that doesn't understand the NEC.

It stated that there was no ground wire in the cable and then mentioned the metal jacket. The photo showed that the cable was AC cable, so there was a ground present in the box.

It also stated that there was no ground wire from the receptacle to the box. One isn't required if the receptacle is self grounding. The photo didn't show it but most receptacles are self grounding and have been for many years.

The insurance company sounds like they want to blame everyone for this fire and will go after the EC even though it seems to be a code compliant installation with no burning inside the box or receptacle.

 

[Sierrasparky]

EC&M magazine has become a pamphlet for advertising and the articles aren't very good.
This article was written by someone that doesn't understand the NEC.

It stated that there was no ground wire in the cable and then mentioned the metal jacket. The photo showed that the cable was AC cable, so there was a ground present in the box.

It also stated that there was no ground wire from the receptacle to the box. One isn't required if the receptacle is self grounding. The photo didn't show it but most receptacles are self grounding and have been for many years.

The insurance company sounds like they want to blame everyone for this fire and will go after the EC even though it seems to be a code compliant installation with no burning inside the box or receptacle.

who says Most are self grounding. I have to be very specific when purchasing receptacles that are self grounding.

 

[Sierrasparky]

Here is that uninformed and ignorant investigators email:
hmurcik@bridgeport.edu

 

[mgookin]

Here is that uninformed and ignorant investigators email:
hmurcik@bridgeport.edu

Professor of EE
Bio: http://www.bridgeport.edu/academics...l-engineering-faculty/lawrence-hmurcik/#acc-2

 

[Sierrasparky]

Professor of EE
Bio: http://www.bridgeport.edu/academics...l-engineering-faculty/lawrence-hmurcik/#acc-2

Yea, That is the problem. He is Educated and a professor and does not know what he is talking about. He commands authority be cause he has certain degrees and background. Nobody would be willing to challenge this guy.

 

[tkb]

Yea, That is the problem. He is Educated and a professor and does not know what he is talking about. He commands authority be cause he has certain degrees and background. Nobody would be willing to challenge this guy.

Just another typical engineer that knows nothing about the NEC or real world installations.

 

[hbiss]

He commands authority be cause he has certain degrees and background. Nobody would be willing to challenge this guy.

Yup. Probably makes a nice buck billing himself out as an expert witness.

-Hal

 

[JFletcher]

The EC who did the initial install is probably long since dead or retired... good luck finding him to sue him.

"Although he clearly suspected an electrical culprit, speculating that one of the appliances in the computer room had overheated, the fire marshal could not pinpoint the exact cause of the fire."

"Initially, in the first phase of the investigation, the insurance company issued a legal intent to sue the companies that sold all of the appliances present in the computer room before the fire. Pending an investigation of all of the appliances..."

wth? Is it standard procedure for insurance co's to sue on speculation or pending investigation?

"Part 1 — First, an identification was made of each appliance and its wires. Note: Many of the wires and cables were melted/burned in such a fashion that they essentially became one charred cable. It took a great deal of patience to separate these wires into their constituent parts and identify the appliance to which they belonged (Photo 1)."

Photo 1 clearly shows one of those power strips having a 2 prong receptacle. If the receptacle is 2 prong, so is the plug.

The knock-off computer...

"Part 3 — During the third part of the initial investigation, experts theorized what might have caused the fire. However, none could point to a clear cause."

" This is a good bond, but the bare wire is NOT in the cable jacket — only a black and white wire run through the cable jacket (i.e., hot and neutral)."

Where the hell else would it be, on the outside? Just a piece of wire shoved in there to look like an AC drain wire? :?:?

Also, that pic shows no substantial fire damage inside or out; the fire didnt originate inside that box. nor anything plugged into its receptacle.

"Why was their no ground wire connected to this grounding-type receptacle? Did it burn up in the fire?"

Yes, it evaporated in the fire, with no trace left, like David Copperwire, magician, removed it. Or maybe it reached sentience and crawled away. This is the dumbest question I have seen in a long, long time.

Not sure if this article is poorly written, or the incident poorly investigated, or both. In any event, this 9 second video clip sums it up:

https://www.youtube.com/watch?v=Ubw5N8iVDHI

 

[al hildenbrand]

No one responded to my post. Let me restate. Using home computer equipment without an EGC or a two prong plug can cause a fire? That is the summary of the article.

http://ecmweb.com/accidents-investigations/case-computer-room-fire

At this point, I've read the print version of the article. "Photo 2", showing the steel wall case and decora-style receptacle, clearly is a photo of an Armored Cable -- Type AC wiring method, which is a grounded wiring method.

In the 1999 NEC, Article 333 is the Armored Cable Article, and, presumably, if the date of condo construction is accurately stated in the EC&M article, is the Code in effect during construction. The armor of the cable is the "Equipment Grounding Conductor" per the 1999 NEC:

1999 NEC
Article 250 -- Grounding
250-118. Types of Equipment Grounding Conductors

The equipment grounding conductor run with or enclosing the circuit conductors shall be one or more or a combination of the following.

(9) Armor of Type AC cable as provided in Section 333-21.

The steel wall case in Photo 2 shows an internal cable clamp that is designed to retain the anti-short bushing required with the Type AC cable, and has a hint of the red color of such a bushing showing in the lower cable examination slot.

The article authors erroneously state: "The assumption is made that the metal box provides a good ground. This is not true."

The metal box, in fact, does provide a good ground, when clamped to Armored Cable Type AC, and the Armored Cable wiring method not shown is wired to the requirements of 1999 NEC Article 333.

The EC&M forensic investigation makes no mention of the decora-style receptacle device yoke screw to box mounting, and whether an auto-ground exists, or not.

I hope the original electrical contractor has expert support that actually knows the Code.

 

[don_resqcapt19]

I sent an e-mail to the author....he replied that testing showed that the box did not have a good connection to ground, but did not provide any details.

 

[tkb]

I wonder what testing was done and if that testing would hold up to cross examination by someone with experience in the trade?

 

[jim dungar]

At one point the author discusses how the baby monitor was ruled out as the source of the fire, because when it was opened there were no signs of a fire on the inside.
Yet the receptacle is being blamed, when it also does not have any signs of a fire internal to its box/enclosure.