[SEL] Early Switchboard Meters and Switchgear

[Tod Engine]

All you need are massive contacts, lots of asbestos shielding and arc 
extinguishers!  The fun of DC is the arcing, sparks, flashes and loud 
noises!   We have a tiny 3 ton overhead crane at work dating to 1923.  It 
runs on 250 VDC and pegs the amp meter (300 amps) when a lift is made.  Its 
all original so what technology they had then we are using now. Now and then 
she puts on a show.

I have access to large amounts of old switchboards, slate panels, knife 
switches etc. from the local steel mills. Lots of 1916 era Westinghouse and 
GE equipment. I wonder if there are any people out there that collect this 
stuff just as we all collect old iron.  A building I rent is a former 
powerhouse in a mill.

Rick

----- Original Message ----- 
From: "Michael P. Koryciak" <guitronics at comcast.net>
To: "The SEL email discussion list" <sel at lists.stationary-engine.com>
Sent: Saturday, July 16, 2005 9:20 PM
Subject: Re: [SEL] Early Switchboard Meters and Switchgear


> On relays, "quenching", or "spike" diodes are put across one of the
> coils to absorb the voltage of the collapsing magnetic field.I imagine
> the same thing will work with switches....in Audio Electronics, a
> high-value (1 Meg ohm) resistor is used on the input of amplifiers to
> eliminate the "Popping" noise of the switch.
>
> John Culp wrote:
>
>>> Quick breaks were fitted to DC switches to prevent arcing across as
>>> the load current was broken. It's still a problem, even today!
>>
>>
>> Direct current still works pretty much the same way as it has for a
>> long time.
>>
>> John Culp
>> Bristol, Tennessee, USA
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>> SEL at lists.stationary-engine.com
>> http://www.stationary-engine.com/mailman/listinfo/sel
>>
>
>


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