<html><body><span style="font-family:Verdana; color:#000000; font-size:10pt;"><div>Ok, I'm a little reluctant to kick this critter much.. because I feel like I must be missing something here... but let me float this notion.. If we <span>stuff<span id="GD__CURSOR"> </span></span>flammable gas producing batteries in an enclosure (and proceed to button them up tighter than a bull's ass in fly season -- fan or no fan), Haven't we just created a Class I Division 1 location? (NEC 500.5). then say we do rely on a $4. fan (OK -- $15.) to declassify as allowed in 500.5(A)fpn, Wouldn't we still have a Class I Division 2 location? NEC 500.5(B)(2)(2)/(3)<span>.<span id="GD__CURSOR"> </span></span>So my point is -- are fully enclosed battery boxes really w<span></span>orth the hassle? are they even A good idea? I can't seem to find where NFPA 70 "Requires" a battery enclosure.. 690 VIII says you need to protect electrical connections (in dwellings) and <span><span>kicks you back to 480<span id="GD__CURSOR"></span></span><span id="GD__CURSOR"></span></span>, but makes no mention of "requiring" a battery enclosure.. 480.8 says basically that if you use racks or trays, they've got to hold up. 480.9 outlines ventilation and working space, but again doesn't "require" enclosures. (480.6 deals with Insulation of batteries.. But I'm thinking they're talking about <span>electrical<span id="GD__CURSOR"> i</span></span>nsulation)... But nowhere in the NEC have I found any mention of battery boxes or Enclosures being "Required".. On the contrary, Seems to me they're suggesting that if by design you can provide for proper work space, adequate ventilation (both out and in) and protect the electrical connections, you're good as far as NEC is concerned.. <span>In NFPA 70E, (Workplace Safety) 320.4 says batteries should be under lock and key (or require a tool for access), and that they be protected both physically and electrically. <span><span> <span><span><span><span>also</span></span></span><span id="GD__CURSOR"> </span></span>in NFPA</span><span id="GD__CURSOR"> </span></span>70E, 320.6 kicks around enclosure requirements some, but seems to focus more on protecting terminals and related equipment.. <span id="GD__CURSOR"></span></span>Now in OSHA 1926 (Subpart K), <span><span>.441</span><span id="GD__CURSOR"> </span></span>seem<span><span id="GD__CURSOR"></span></span>s to be where "required enclosures" originates, but again, it seems to be referring to commercial workplace safety... (i.e. also requires that "the charging apparatus be protected from damage by trucks" and "eye wash stations be provided within 25 feet" etc.).. I'll will tell you the majority of the failed / scummed out battery banks I've dealt with have been from poor ventilation, poor maintenance or defective / improperly designed or installed battery boxes.. If I can, one of the first remedy's I apply is to drill several large holes (and staple some kind of critter proofing over the holes from the inside). -or- if I can gracefully, I'll remove the sides altogether -- as long as the electrical connections are protected. also if I can, I try to find a way to route exhaust gases so they vent naturally -- so they don't rely solely on a vent fan... like maybe run 2" PVC up thru the roof -- inside the envelope of the house. at least try to make sure the fan is not competing with the furnace or exhaust systems... (like insure there's an adequate <span>intake air<span id="GD__CURSOR"> </span></span>supply for the whole house)... as for protecting batteries from fluctuating temps.. the planet <span><span><span>(some three feet down anyway)</span><span id="GD__CURSOR"></span></span><span id="GD__CURSOR"> </span></span>stays just over 48 degrees.. at least in these par<span><span id="GD__CURSOR"></span></span>ts.. Just saying.. db<br></div><div> <br>Dan Brown<br>Foxfire Energy Corp.<br>Renewable Energy Systems<br>(802)-483-2564<br><a href="http://www.Foxfire-Energy.com">www.Foxfire-Energy.com</a><br>NABCEP #092907-44</div><div><br></div></span></body></html>