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#109911 - 01/01/06 11:54 AM Auto Shop #2 - more Horrors ....
Webmaster Offline

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Registered: 10/07/00
Posts: 3142
Loc: NY, USA
 Quote:
Building on a thread started by "Lotsahell," here are the first pics from a transmission shop I'm currently working on.

The first pic is of the starter open; as you can see, this is a single-phase unit.
 Quote:
The second pic shows the box feeding the com[pressor, as I found it. Please note the absense of either a cover or disconnecting means. Not so obvious is that there are three large wires, plus a ground wire, going to the compressor. This is one wire more than is neede for a single phase unit.
 Quote:
A look behind the unit (pic 3) shows what happened to the lost phase- it was simply capped off at the flying splice.

- renosteinke

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#109912 - 01/02/06 07:02 PM Re: Auto Shop #2 - more Horrors ....
Lostazhell Offline
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Registered: 02/21/04
Posts: 1248
Loc: Bakersfield, CA (Originally Or...
why do I get the feeling that all of this tomfoolerly is outside for the weather to wreak more havoc on than already exists.... Some people just shouldn't be allowed contact with more than 12V!

PS. nice pics John..

-Randy

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#109913 - 01/02/06 08:55 PM Re: Auto Shop #2 - more Horrors ....
mahlere Offline
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Registered: 11/17/05
Posts: 514
Loc: New Jersey
ironically, NJ passed a law that a license is required for anything over 10v.

not sure if it's being enforced though.

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#109914 - 01/03/06 12:23 PM Re: Auto Shop #2 - more Horrors ....
chipmunk Offline
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Registered: 07/20/04
Posts: 142
Loc: Southampton, UK
 Quote:
ironically, NJ passed a law that a license is required for anything over 10v.

That would be a good idea in some cases, 12v from a car/truck battery can do a lot of damage, but that would cover phones too (Unless there's a specific exclusion). The phone companies however might think that was a good idea

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#109915 - 01/03/06 03:43 PM Re: Auto Shop #2 - more Horrors ....
Rewired Offline
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Registered: 01/01/06
Posts: 567
Loc: Hamilton, Ontario, Canada
Yep, 12V is "safe" but when you have a few hundred amps availible and ya' short across it, things kind of get a bit hot let alone all the 'pirty sparks.. Very easy way to say start your car---> on fire. ( seen it)
Telephone?? Get your buddy to work on it.. If they don't feel the 50V D.C present, CALL THEM... See if they feel the 90V A.C "ring"

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#109916 - 01/07/06 06:53 PM Re: Auto Shop #2 - more Horrors ....
Theelectrikid Offline
Member

Registered: 04/30/04
Posts: 854
Loc: Levittown, PA
"why do I get the feeling that all of this tomfoolerly is outside for the weather to wreak more havoc on than already exists.... Some people just shouldn't be allowed contact with more than 12V!"

If you ask me, some people shouldn't be allowed to touch a "AA" battery!

Ian A.
_________________________
Is there anyone on board who knows how to fly a plane?

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#109917 - 01/08/06 07:04 AM Re: Auto Shop #2 - more Horrors ....
pauluk Offline
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Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
 Quote:
Yep, 12V is "safe" but when you have a few hundred amps availible and ya' short across it, things kind of get a bit hot let alone all the 'pirty sparks..


Definitely. So many times I've heard comments like "Oh, it's only a low voltage, it can't do any harm."

In the communications facility where I worked years ago we had the usual DC busbars running around above the racks for power. There were the usual 50V telephone equipment supplies, and we had a separate 28V distribution system for some of the satellite equipment. Some folk wouold scoff at the fuses and protection on that 28V system, but those busbars were fed from one heck of a big battery bank. The short-circuit current would have been well into the four-digit range, possibly even five.

At one point on the floor underneath the busbars was a patch where you could still see the burn marks from a slip made some years earlier. Apparently somebody accidentally dropped a wrench while working above on the cable trays and it bridged the bars as it fell. Needles to say, it was no longer usable for its intended purpose!

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#109918 - 01/08/06 03:15 PM Re: Auto Shop #2 - more Horrors ....
wa2ise Offline
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Registered: 11/29/02
Posts: 771
Loc: Oradell NJ USA
 Quote:
Some folk wouold scoff at the fuses and protection on that 28V system, but those busbars were fed from one heck of a big battery bank. The short-circuit current would have been well into the four-digit range, possibly even five.


I've heard stories about wedding rings and car batteries. That one needs to remove the ring before working with such batteries. Else you could literally burn your finger off from the heat of the fault current thru the ring from +12V to ground....

Once had a boss who had an ivory wedding ring (non-conductive material) to avoid this hazard, as well as any wayward smaller hot wires accidently getting under the ring to make a "good" connection to his body for a shocking experience.

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#109919 - 03/06/06 07:42 PM Re: Auto Shop #2 - more Horrors ....
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Registered: 10/07/00
Posts: 3142
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 Quote:
Here is a pic of the compressor after I re-wired it.

- renosteinke

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#109920 - 03/07/06 03:55 AM Re: Auto Shop #2 - more Horrors ....
IanR Offline
Member

Registered: 12/06/04
Posts: 326
Loc: Palm Bay FL USA
Well, that looks much more respectable

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