battery box fan [RE-wrenches]

[Jeffrey Wolfe, Global Resources]

I would caution that you should check out the components of the fan. Is it 
all platic? Is there anything that "could" rub to create a spark? I quite 
frankly think that it's a pretty extreme case where we get enough H2 from 
an average battery bank to create an explosion (except in a very small 
confined space with a local spark.) Howerver, if we're going to put in 
battery vent fans, they ought to be "explosion proof". The Cone vent fans 
have been "tested" although they are not "certified" or "listed" for this 
purpose by anyone.

The only battery melt down experience I've been involved in was a *very* 
large UPS for Digital Computer. Over 100 batteries. Brand new installation, 
and the charger (large industrial type, I have no idea of the manufacturer) 
failed in "charge" mode. Basically melted all the batteries. Room had a H2 
sensor and a dedicated large fan for exhaust. H2 levels never got high 
enough to trip the sensor, even though the battery salesman said it was the 
closest he had ever seen to a complete battery failure.

So we put the fans in (except in tiny systems where we vent through the 
wall w/o fan), but I don't particularly believe in the need. Anyone else 
had experience with H2 accumulation?

Jeff

Jeffery D. Wolfe, P.E.
Global Resource Options, LLP
A Woman-Owned Vermont Limited Liability Partnership
4 Kibling Hill Road
P.O. Box 51
Strafford, VT 05072
802/765-4632
802/765-9983 (Fax)
global at sover.net
www.globalresourceoptions.com


----------
From: 	Bob Ellison, Alternative Energy Systems[SMTP:ellison at gisco.net]
Reply To: 	RE-wrenches at topica.com
Sent: 	Wednesday, November 22, 2000 1:00 PM
To: 	RE-wrenches
Subject: 	battery box fan [RE-wrenches]

For the last couple years I have been using a Radio Shack blower for 
venting
battery boxes.
It is Cat. # 273-260
Described as a 12 volt DC brushless blower (Squirrel cage). The size is
3"x3"X1" Power consumption is .18 amp @ 12 volt
It turns @ 2600 rpm and is reverse polarity protected and according to the
diagram on the box it pushes over 8 CFM. With a SW inverter you can use a
relay to turn it on, otherwise I just put it on a lit switch (outside the
battery case) they can turn on when equalizing the batteries. I put the
blower into a piece of conduit and seal it with silicone to vent the gas 
and
if the pipe rises enough it seems to self vent well enough for all but
equalizing the batteries.
Hint, DO NOT try to run it on 24 volt, it will not work and I just can't
seem to get the smoke back in the case!

The reason I am bringing this up is they're are discontinuing it and they
are $5.97 while they last.
You might want to check them out, they work nice.


Bob Ellison



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To unsubscribe send a message to: 
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To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine: 
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

___________________________________________________________
T O P I C A  http://www.topica.com/t/17
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