CABLE BOX EXPLOSION NEAR METER

[Cybatrex]

If you notice next to this metered box there existed a DMARC where the underground feeder for XFINITY came into the home. That dangling thing hanging from the metered box is where the connections unionized. Do you think that this was due to a lightning strike and because of the poor bonding of our copper ground to the metered box not being where it should that this caused this?

Let me know your opinions as to how you think this happened.

 

[mopowr steve]

First glance looks to be lightning strike damage, if there was a open neutral on the utility side I would expect to see some melting of the jacket on the coax or its grounding wire. Speaking from experience.

 

[Cybatrex]

First glance looks to be lightning strike damage, if there was a open neutral on the utility side I would expect to see some melting of the jacket on the coax or its grounding wire. Speaking from experience.

If its grounded to that meter why would an open neutral cause this, wouldn't it dissipate to GEC that is also in the box?

 

[mopowr steve]

Only when a coax comes from utility poles does it lend itself as a parallel neutral path via the shielding of the cable. If utility neutral opens due to corrosion or damage then high currents will use the shield to return current back to transformer. These higher currents often times will melt if not start a fire on the coax and/or its grounding apparatus. Ground rods will never be able to sink enough current (due to ground resistance) to keep bad things from happening.

Since it looks to have blown the box off the wall, I would say a splitter grenaded durring a strike.

Lightning is the resulting arc of two charges. Charges so great that it will arc across miles of air space. No little POS in a box has a chance of survival in a direct hit.

 

[mbrooke]

If its grounded to that meter why would an open neutral cause this, wouldn't it dissipate to GEC that is also in the box?

More current will flow on the COX shield then the grounding electrodes back to the POCO due to the COX shield having a lower resistance. Unfortunately something like 18 gauge wire isn't going to handle 40 amps like a 4/0 neutral- so a LOT more I2R losses.

Here is a "milder" version in that no fire started:

https://www.electrical-forensics.com/Open-Neutral/Open-Neutral.html

 

[mbrooke]

Only when a coax comes from utility poles does it lend itself as a parallel neutral path via the shielding of the cable. If utility neutral opens due to corrosion or damage then high currents will use the shield to return current back to transformer. These higher currents often times will melt if not start a fire on the coax and/or its grounding apparatus. Ground rods will never be able to sink enough current (due to ground resistance) to keep bad things from happening.

Since it looks to have blown the box off the wall, I would say a splitter grenaded durring a strike.

Lightning is the resulting arc of two charges. Charges so great that it will arc across miles of air space. No little POS in a box has a chance of survival in a direct hit.

Not saying it is- but could also be 7000+ volts getting on the shield from a primary falling into the phone lines.

 

[mopowr steve]

Not saying it is- but could also be 7000+ volts getting on the shield from a primary falling into the phone lines.

I agree, It was just based on first assumptions.

Though now I see he is from Florida and that is quite possible with the recent hurricane winds.

 

[mbrooke]

I agree, It was just based on first assumptions.

Though now I see he is from Florida and that is quite possible with the recent hurricane winds.

Not to worry- I myself am also assuming. Could be any of those 3 things.

 

[JFletcher]

Pretty sure it was hit from a blast of an Illudium Q-36 explosive space modulator... or lightning for those who still believe in 21st century conspiracy theories.

 

[Netpog]

...Illudium Q-36 explosive space modulator...

For those of you who didn't immediately catch the reference to the classics...

http://evil.wikia.com/wiki/Illudium_Q-36_Explosive_Space_Modulator