144vdc charging [RE-wrenches]

[Dean T. Newberry]

<x-flowed>
 

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Apply now for a No-Annual-Fee Discover® Platinum Card 
0% Intro APR*, No Annual Fee, Up to 2% Cashback Bonus® 
award* Start Saving Today – APPLY NOW! It's fast, easy and 
secure.
http://click.topica.com/caacpgwbz8Qcsbz9JC9a/DiscoverCard
-------------------------------------------------------------------

Hi y'All
In the 60's we had 60VDC, 60 milliamps per circuit, polar ie 120VDC 
battery banks for teletype switching centers. There were lots of systems 
out there at that time I have seen ISP backup systems on the same scale 
in the last ten years. The batteries were in steel earthquake racks, had 
industrial venting over the whole bank. I don't know what the current 
draw was, but the bus bars were 1/2" x 4" copper out to the distribution 
box. I toured the Bell Telephone teletype switching center on Wall 
Street in 1966, the com center was on the 13th floor, the batteries were 
so heavy they chose to reinforce the building rather than run the 120VDC 
200' or so. The buss bars on that system were 6" x 3". The systems 
required very little maintenance, but I did get a nice arc while redoing 
the grease on the last positive terminal where it was just a few inches 
from the negative, there was a nice little fireball sent up the vent I'm 
guessing from some gas from charging the system. We changed the 
maintenance procedure to only check and repair the grease, not replace 
it semiannually. Monthly maintenance was to check the electrolyte 
concentration and level. I don't remember ever adding water to that system.
Just pay attention, keep one hand in your pocket when working on the 
stuff, so you don't get a jolt through the heart. If you do get a zap 
through your chest, go to the ER.
If your heart has a sustained contraction, etc. it may swell up just 
like your hand, it takes time, and you will be glad you spent the time 
getting to the hospital instead of just returning to work. If this 
happens to your partner it is your responsibility to insist that he get 
prompt medical treatment, the injured person may not be rational after 
the accident.
cul deant

Hugh Piggott wrote:

>
>
> Your free subscription is supported by today's sponsor:
> -------------------------------------------------------------------
> Apply now for a No-Annual-Fee Discover® Platinum Card 0% Intro APR*, 
> No Annual Fee, Up to 2% Cashback Bonus® award* Start Saving Today – 
> APPLY NOW! It's fast, easy and secure.
> http://click.topica.com/caacpgwbz8QcsbdulIia/DiscoverCard
> -------------------------------------------------------------------
>
> At 7:45 AM -0700 18/7/04, Darryl Thayer wrote:
>
>> I have
>> heard that 'excel tec'? makes inverters of Odd
>> voltages.
>
>
> This 144V thing sounds like a 120 volt nominal battery. If so then you 
> can go to Exceltech. I also recommend Power solutions Australia for 
> high power 120 VDC synch/sine inverters, although they maybe only do 
> 50 Hz.
> http://www.powersolution.com.au/profile.htm
>
> 120 VDC makes a lot of sense for high power systems and I wonder why 
> it is so rarely seen.

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Save up to 67% on Omaha Steaks + Get 6 FREE Burgers and a 
FREE Cutlery Set + Cutting Board!
http://click.topica.com/caacpgjbz8Qcsbz9JC9f/OmahaSteaks
-------------------------------------------------------------------

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & etiquette: www.mrsharkey.com/wrenches/etiquete.htm

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------



</x-flowed>