Fw: Battery Cables [RE-wrenches]

[Allan Sindelar]

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Save on inkjet and toner, and get free shipping on orders over $50.
http://click.topica.com/caacBBybz8Qcsbz9JC9a/Inksoutlet
-------------------------------------------------------------------

Wrenches,
Forward:

Allan:
Wish I had time to keep in touch with all the traffic on the Wrenches Web
site. If you have time, please post the following:


Battery Cables:

You old PV Pros have a look in your 1996 Code book in Section 690-74
and see that the first allowance for the "permitted" (not required)
use of flexible, Article 400, battery cell interconnections required
that they be acid resistant.  Note that does not say acid "proof".

However, in the deliberations for the 1999 NEC, UL engineers decided
that the typical environment in a battery enclosure was not
sufficiently acidic to warrant the requirement for even acid
resistant cables and that all commonly available building cables with
both thermoplastic insulations (THHN, THWN, etc) and thermoset
insulations (USE, RHW, RHH, etc) were sufficiently acid resistant for
the application.  For that reason, the requirement for "acid
resistance" was removed from 690.74 in the 1999 and subsequent
editions of the NEC.

That being said, there are applications covered by the code where
high degrees of acid resistance and acid proofing are required.
These are found in industrial applications and chemical process
plants where the cable insulations are exposed to continuous contact
with highly concentrated acid vapors and liquid acids.  Section 310.9
would apply to those installations.

Yes, we have all seen the badly miss-adjusted or failed charge
controller or overfilled batteries with electrolyte spilled all over
the enclosure (if one was used) and possibly the cable insulation may
have been damaged if submerged in the electrolyte and it was
sufficiently concentrated.  However, do we really want to say that is
a common occurrence?  If so, that type of battery operation, if
common, with excessive acid and hydrogen evolution could lead to
enforcement of NEC Section 408.10 requiring flame arrestors on vented
cells and Article 500 dealing with hazardous locations and very
expensive equipment, and possibly required power vents and acid
containment systems.  I don't think we want to go in that direction.

In a related area, some degree of caution should be used when talking
with the engineering/sales staff at a cable manufacturer or any
electrical equipment manufacturer.  Each company makes cables with
proprietary coverings, each with different properties or in some
cases no differences at all-just different names.  Each company wants
to sell its products and may make recommendations that show there
products in a more favorable light than those of their competitors.

Go for the gold?  Exceed code requirements and minimums?  By all
means, use tinned, rubber-insulated battery cables.  With proper
parts, installation techniques, and sealing of the lugs to the
insulation, those cables will probably outlast several generations of
users.

Me? I just use THHN or USE/RHW cables in battery boxes and #$%$# at
the stiffness of them.
-- 
If I can provide further information, please do not hesitate to call,
e-mail or fax me.

John

John C. Wiles,  Program Manager
Southwest Technology Development Institute, New Mexico State University
505-646-6105      505-646-3841 (FAX)   http://www.NMSU.Edu/~tdi
SWTDI/NMSU
Corner Research Drive and Sam Steel Way
Box 30001/MSC 3 SOLAR
Las Cruces, NM 88003-8001

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Amazing Diet Patch
The fastest - Easiest way to lose weight! Try it now FREE!
http://click.topica.com/caacBBBbz8Qcsbz9JC9f/MyDietPatches
-------------------------------------------------------------------

- - - -
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
--^----------------------------------------------------------------