What's wrong here #3


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The post is courtesy of Ship, who has asked that I post the pictures for him.




The relevant information at this stage is:

Ship said:
Given it was not a overloaded circuit, what's the cause of this? What could have prevented it?
Well, there'a lot of rust on the copper wires. Bearing in mind that the principal cause of rust is long-term exposure to water, then the wires must have been bare somewhere. So, somehow, this piece of equipment must have been exposed to water for a long period of time, or never dried off after it was exposed.

I suppose that water that deep into the workings of the equipment could have done something like shorted it. This would have been all too easy, given the amount of bare wires visible in the picture.

As for prevention, well, provided my theory is correct, then the obvious measure woudl be to keep the equipment dry and clean.
i would sya keep water away and run a dehumididfier in the room with it for a while(but not too long or you will get some nasty static electricity buildup, zap!!!
i would also agree with the other posts, but in regards to the "what could have been done to prevent this?" part of the question, heat shrink to conver the wire and being kept dry, sometimes, sh*t happens, and if your equipment gets wet, it should be dried thorughly and quickly and if it is not should be replaced before it gets this bad
Wow, that's quite bad!!

[Edited to fix my complete ignorance :) ]

Ya, this looks like it was quite wet!! I would suggest that electronics not be used in the rain or in the ocean! lol! The dehumidifier idea sounds like it could be alot of good! Or maybe find a friend who can get a TON of those little packets you find in your new shoes that are made to abosorb the moisture in the shoe!
Mayhem said:
The post is courtesy of Ship, who has asked that I post the pictures for him.

The relevant information at this stage is:

Ship said:
Given it was not a overloaded circuit, what's the cause of this? What could have prevented it?


off the top of my head...excessive heat...exposure to moisture (salt water too it looks like)..over stripped wires...unshielded or insulated with no heat shrink (plus could have used a better means of connecting other then a barrier strip)...plus its stranded and doesn't look like its proper wire for a high heat/mositure area. No silicon over the connection to protect it from exposure to salt or humidity..although thats a bit extreme. Also, and maybe its just me, but usually for barrier strips/buss bar of this style that are meant for use in a power panel (on a ground or neutral buss), you want to use solid core wire, not stranded wire. Better to have used an insulated strip with each wire individually wire-nut together or the use of spade lugs....

This was not a case of water, and the case of two seperate instances amongst about six before we started sending the 400 amp three phase AC distros back for total re-wiring because of this and other problems at a cost in shipping along of about $400.00 per pack for about 20 packs amongst many packs with similar needs for my attention for other reasons.

The first instance resulted in an improvement of mine due to the wire of one conductor rubbing against the sharp edge of another buss bar on a opposing phase as it were while as part of a large assembly of 100 amp buss bars distributed amongst the 400a, three phase panel. Worked well until a second problem showed up as per the second left hand photo.

First more field fix was to ensure no more rubbing of even insulated conductors could happen, then the second and third and fourth examples in opposing locations started to happen with loose screws not water. Just settling of conductors once clamped to the proper torque setting the manufacturer states they did. Granted such conductors both heated in expanding and cooled, much less bounced around in the back of a semi, between shows, I have no doubts that the clamping pressure on wire was proper - get over this torque already, now lets lood at the subsiquent settling of the wire due to lack of ferrules in keeping them one piece as opposed to settling. - oops!

Final picture shows the end results of a wire I think that did not have a ferrule and was later confirmed not to have one in just plain re-settling after heated. It in carrying 100 amps of load was simply installed into a non-UL listed distro buss bar using grounding/neutral lug assemblies to distribute the load from the 100a breaker by way of #6 wire to various - often seven #12 conductors forced into their own various holes without also a ferrule.

In other words, some electrical engineer used some 1/4" hole lugs in attaching to some #8 hole grounding bars, than hoped beyond the lack of specifing the use of ferrules, hoped the isolation bar attaching it to the rack was sufficient for the consiquences. In the end, these racks blew up during some very high profile shows once the wires either rubbed thru an opposing phase they were right next to or the wires settled them selves down into a high resistance contact of loose wires all over the place. Want to imagine my frustration, one of these racks alone in ensuring the nuts on breakers and buss bars alone takes about three hours and we own at least 16 of them of this specific brand.

In any case, the manufacturer after shipping costs is now complelely re-wring the equipment at their own cost in adding things like lock washers to the circuit breakers and changing out these 100a distro areas from stuff that's not designed to do this, to what's called a Mariton block that does this safely as required. Ferrules, lock washers and insulation in various places as pointed out will also be used all around.

End result, a year of blowing up racks for reasons that just expanded in cause as the year went on and I or my assistant did quick fixes at from two to eight hours per rack yet they found a new way of blowing up. After that, what is it , $6.4K alone in just shipping costs not re-imbesed but factory re-wired racks. Six months from now they will all have new gizzards. Until each gets it's chance to go back, I bite my nails as to what length of time the next rack has until it blows up.

Ea, nice stuff especially centered around the photos.

Rack seriously blows up during a show and afterwards comes back to you with a note saying it's bad. It's both your job to repair and fix all other equipment with similar problems, much less not only figure out the case but advise the vendor on where they screwed up even if they have 20 more years in the industry than you have. Thus my own job often at work in being some form of crime scene detective and solution person where lives are involved. What you see here needs no cause effect further, just a note that beyond me, you very likely in some time in your career will see similar things go wrong. You than will need a process of elimination of a base of kowledge to find the cause and solve the problem even if not eventually in doing what I do. Rack has to run, how do you make it do so.

This was all heat damage, no water involved. Perhaps at some point I will take a photo of the Sting - Central Park show of a few years ago where a Socapex type plug did get under water action - at least after I extacted the two apart after wards a photo of the inside of one.

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