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#73143 - 12/18/06 09:06 PM Powerbook Explodes After Comcast Plugs in Wrong Cable  
caselec  Offline
Member
Joined: Apr 2002
Posts: 558
San Jose, CA
http://www.consumerist.com/consumer...-comcast-plugs-in-wrong-cable-222665.php

I would like to know what really happened here. I don’t see how the cable tech could cause this much damage by connecting the “wrong cable”.

Curt


Curt Swartz

Work Gear for Electricians and the Trades

#73144 - 12/18/06 10:08 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
Elviscat  Offline
Member
Joined: Aug 2005
Posts: 214
Seattle Washington USA
"It seems likely that the young technician connected the rooftop end of the cable to a similar-appearing, but now obviously incorrect electrical cable"

I smell a rat, anyone else think this a wee bit improbable?


#73145 - 12/18/06 10:11 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
I woud say that to the totalaly untrained - an unused SE drop would 'look' simular, and be quite capable to cause this damage. And the decsribtion sound as if just that happened.

I tried to post on that forum, and asked if we could get pic's of 'what' this cable guy connected to.

I'm trying to imagine someone putting an RG-6Q connector on a service drop. [Linked Image]


Mark Heller
"Well - I oughta....." -Jackie Gleason

#73146 - 12/18/06 10:15 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
Elviscat, I'll bet you a beer that it was a pre-MCOP short. If you have ever had one - not suggesting you do, but it sounds, and even smells exactly as decribed there. Full brunt of POCO will go off like a grenade - trust me...


Mark Heller
"Well - I oughta....." -Jackie Gleason

#73147 - 12/18/06 10:23 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
Theelectrikid  Offline
Member
Joined: Apr 2004
Posts: 810
Levittown, PA
$10 (Mark's beer money [Linked Image] ) says that it's at least partly Apple's Fault. And this is coming from someone with an iBook on their lap right now.

Ian A.


Is there anyone on board who knows how to fly a plane?

#73148 - 12/18/06 10:37 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
RODALCO  Offline
Member
Joined: Dec 2005
Posts: 854
Titirangi, Akld, New Zealand
It iooks like that the coax got connected to the mains 120 or 240 Volts or perhaps even a higher voltage to that kind of damage.


The product of rotation, excitation and flux produces electricty.

#73149 - 12/18/06 10:45 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
Sorry kid, this is why one never plays with downed power lines!!!! The AIC for a main circuit breaker connection is ~10,000 amps plus. The connections before it are without any protection for the most part, there are usualy no fuses and a short will recieve all that the neighborhood transformer can deliver - instantaniously and contiuously thoughout the duration of the short!

I relay a story as an example..... I was closing a gutter about ten years ago while on a 20' ladder. The gutter was on the POCO side of the meters and mains, and a set of the 250MCM conductors had some spring to them when pushed in the box. Notheless, it shifted as I was putting the cover on, and the split-bolt slapped against the cover, and pierced the tape covering it creating a short to the cover I was holding at face level. It blasted a 3" hole in the cover, sounded like a grenade, and splattered molten metal specs into my face, and shirt! I then rolled down the ladder, and luckily got caught 1/4 of the way down by one leg, the ladder rolled over and I then rode it to the ground upside down. Not hurt by the fall - but the flash tepmerarily blinded a portion of my vision - a big white spot. Not to mention my nerves were pretty shot.... I had to go out to replace the cover the next day, and it took several hours for me to get the nerve up to even climb the ladder without shaking. And since then I have learned quite a lot about proper PPE and the reasons for it... Did I mention that I am one of the luckiest persons I know????

120 - ground will do it... The damage will be proportional to the size of the transformer and relivant distance to it. Look up Arch Flash Calculations.


[This message has been edited by e57 (edited 12-18-2006).]


Mark Heller
"Well - I oughta....." -Jackie Gleason

#73150 - 12/18/06 10:54 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
brianl703  Offline
Member
Joined: May 2005
Posts: 166
Manassas, VA
I would think that the circuit board traces in the modem would burn up long before anything in the Powerbook ever did. (I am well aware of the effects of 120V on circuit board traces. I have never seen one continue to arc over after the trace burns up).

[This message has been edited by brianl703 (edited 12-18-2006).]


#73151 - 12/18/06 10:58 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
I would say that all of that damage was instantanious...


[This message has been edited by e57 (edited 12-18-2006).]


Mark Heller
"Well - I oughta....." -Jackie Gleason

#73152 - 12/18/06 11:02 PM Re: Powerbook Explodes After Comcast Plugs in Wrong Cable  
brianl703  Offline
Member
Joined: May 2005
Posts: 166
Manassas, VA
You'd think, but I've seen circuit boards where 120V was applied directly to the 5v/12v power bus and not every chip on the board was (physically) damaged--the traces gave up before the chips did.

[This message has been edited by brianl703 (edited 12-18-2006).]


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