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Trumpy #165836 07/06/07 09:19 AM
Joined: Nov 2001
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Does it concern anyone that, in order to replace a burned out fuse in this panel, you have to open some type of main disconnect (also a fairly frightening-looking device, I'm sure) ahead of this panel and kill all these circuits?

Only a person intent on committing suicide would try to replace a fuse while this panel is energized.

AGREED! If this panel runs hot enough that the door has to be left open, there are serious problems here. Many years ago, I saw a large fuse panel in a theater projection room where the entire panel front was removed due to the intense heat inside - you could literally feel the heat radiating from the panel as you passed in front of it. A middle-of-the-night electrical fire was the eventual outcome.

Mike (mamills)

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Trumpy #165837 07/06/07 09:21 AM
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Mike: (Trumpy); mamils snuck in above
Panelboards like the one in the pics are not 'common'...but there are still some around. Probably from the 1940-1950 eras.
Not 'home made'; this area was Federal Pacific, Westinghouse, Colton (local), Gavin-Graham,and a few other 'local' panelboard mfgs.

As I mentioned above, the 'heating' problems usually are from bad tension connections at the fuseholder clips. The tension knob devices in the pic, and the one laying at the bottom of the cabinet.

As to the bare buss, that's how it was; also the guage of the enclosure is probably double or more of today's enclosures.
John

Last edited by HotLine1; 07/06/07 09:23 AM.

John
Trumpy #165840 07/06/07 10:47 AM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
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In fairness to this situation ...

I have seen several similar installations. In each case, the equipment - usually an ordinary breaker panel, sometimes a motor starter enclosure with overload elements - was in an area where there was something else applying heat to the panel. For example, a nearby oven. This higher ambient resulted in false tripping, and the open cabinet / fan was a solution to that problem.

Mind you, I'm not defending the practice! It's just that you need to understand what the cause of the problem is, before you can try to fix it.

Even where allowed by the code, I try not to solve problems by using a larger breaker / fuse. Doing so seems to 'teach' the uninformed that big fuses are OK ... when that's not the case at all!

Mike, as to all that exposed stuff in the cabinet ... this is very common in equipment of that age. That panel was probably built before WW2.
Fuses such as these are often changed 'hot,' with the load disconnected. That's why we have fuse pullers!

Then again, some understand current rules to require locking out a breaker before changing a light bulb. Just goes to show you how much times have changed ....

(After all ... remember when ashtrays and lighters were common promotional give-aways?)

mamills #165855 07/06/07 02:47 PM
Joined: Oct 2004
Posts: 806
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Hi Mike:

Like Reno said, this type of panel was fairly common construction back then. If used within its ratings and given even token attention to upkeep, it will outlast any of the junk made today. Heck, it already has come to think of it.

SEE THIS THREAD AND ITS MATES for more examples of the older style construction.

I think in part two I show the fuse holders and note how I think one would change the fuses "hot".

Quote
Many years ago, I saw a large fuse panel in a theater projection room where the entire panel front was removed due to the intense heat inside - you could literally feel the heat radiating from the panel as you passed in front of it. A middle-of-the-night electrical fire was the eventual outcome.


I've run into a few similar situations, and the main switchgear at Avalon (In a separate room downstairs, I didn't get pics) is a hodge-podge of old fuseholders and circuit breakers kludged into the framework (it was an open-switchboard design), it too let off a fair amount of heat walking near it.

One thing about your theatre panel quoted above...why did the fire happen in the middle of the night, when one would think the panel had less load on it? Do you have any more details about that incident?




Stupid should be painful.
mxslick #165900 07/07/07 11:02 AM
Joined: Nov 2001
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Mxslick: Yeah, I know panels were made like this many years ago. Our Baptist church here (1926 vintage sanctuary) had two such panels - one very large one in the basement with numerous knife switches and fuseholders mounted on soapstone, marble(?), or some such non-conductive base, and a smaller panel near the sanctuary for controlling the lights (while singing "Nearer my God to Thee" for good measure). The construction work was as meticulous as it was deadly.

Concerning the theater fire, this happened about 30 years ago. I am also at a loss to understand why this would happen at a time of day when the load should have been less - no marquee lights, projector motors, sound equipment, auditorium and lobby lights, etc.
On many occasions when I would come in to open up, I would find numerous fuses so hot that they would burn my fingers. In addition, I could actually see some of the plug fuse elements showing a dull red glow in the dark - I never could understand this. Thinking this meant a bad fuse, I replaced it - same thing. I reported this to the manager several times and nothing was ever done. Even friends in the electrical business were unable to explain this situation. Everyone did agree that this was a potentially life-threatening condition.

Sorry to be getting off-topic...

Mike (mamills)

Trumpy #165923 07/08/07 01:32 AM
Joined: May 2005
Posts: 247
T
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I'd date this as 1920's or 30's, probably not as late at the 1950's.

I don't think the white rope hanging down on the line side is asbestos wire, it looks more like some white rope/sash cord, possibly being blown sideways by the fan.

Admin #165931 07/08/07 06:23 AM
Joined: Jan 2003
Posts: 4,391
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I am going to be honest here.

I have used a fan to keep some breakers from tripping.

I had a night time service call to a long existing grocery store, they had lost a couple of lighting circuits. Well I found the circuits had tripped but many of the other breakers in the panel where also warm.

A little checking with the amprobe showed all 20 amp lighting circuits to have at least 18 amps of load with a few over 20 amps.

So....out came the fan to keep the circuits on that night and the next day a crew was there breaking up the circuits.

Of course I did not leave any live parts exposed.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
iwire #165969 07/09/07 03:51 AM
Joined: Oct 2004
Posts: 806
Member
Bob, now that's the proper use of a fan to prevent a bad situation from getting worse! As a very temporary solution to keep a major client on-line, with the proper repairs done promptly. grin

The subject panel in this thread and the lame excuses provided by the building owner are, however, almost criminally dangerous.


Stupid should be painful.
mamills #165970 07/09/07 03:54 AM
Joined: Oct 2004
Posts: 806
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Quote
I am also at a loss to understand why this would happen at a time of day when the load should have been less - no marquee lights, projector motors, sound equipment, auditorium and lobby lights, etc.
On many occasions when I would come in to open up, I would find numerous fuses so hot that they would burn my fingers. In addition, I could actually see some of the plug fuse elements showing a dull red glow in the dark - I never could understand this. Thinking this meant a bad fuse, I replaced it - same thing. I reported this to the manager several times and nothing was ever done. Even friends in the electrical business were unable to explain this situation. Everyone did agree that this was a potentially life-threatening condition.


Wow, Mike, now that's one for the electrical forensics file...either that or the building was haunted!! Don't think I'd ever seen a situation with glowing plug fuses..anyone else here seen such a thing? Wow.


Stupid should be painful.
mxslick #165980 07/09/07 09:30 AM
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MxSlick: This old theater may well have been wired by some ancient electrician who stayed around to haunt the joint. It had some very strange wiring. The main service equipment was located in a mechanical/air conditioning room at the back of the building. There were two enormous main EXO disconnects. I remember one contained three poles and three fuses, plus neutral. The other switch had three similar poles, but a single line/load conductor to only one fuse (?). I never did find out what kind of voltages were coming out of this stuff - it made me nervous to go anywhere near this mess. Both of these switches dumped their load conductors into a large wire gutter with more exo's than you could shake a stick at.

I wish I still had one of those strange glowing fuses. I don't even know who manufactured it. It had a glass body, and the small cardboard label that resides behind the fuse link was gone (burned away, maybe?). The only identifying mark was a "30" stamped into the center contact.

Mike (mamills)

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