Location of backfeed breaker

Jetskier

I'm trying to determine the best location to install the backfeed breaker.  Generally, the rule would be to install it on the opposite end from the main; however, my panel is set up with 6 slots, the four post 200 A main, and then two slots.  the feed lugs to the sub panel are then under the the last two slots.  I'm thinking that the best place for the 60 amp backfeed breaker is under the main so that it is in between the main and sub panel wiring.  (I wish that I could post a picture.)  The panel is rated for 250 A max, so I don't have to derate the panel.

Currently my panel is set up as follows:  (note: if I install the backfeed breaker in the bottom, I don't have to move anything, but I don't mind moving breakers if I have to.)


Empty 2 Pole HOM service disconnect 50 A. max (I wish this was 60 A and then I would install it here as it would be a basic  backside line tap as it goes back to the meter)

60 amp double pole breaker to pool sub panel
30 amp double pole breaker to A/C
30 amp double pole breaker to A/C
200 amp four pole main
open space
open space
feed through lugs

Are the two open spaces the best place to install, or should I move the pool sub panel breaker down and install the back feed breaker there?  Does the NEC have a requirement?

Thanks,

Note: I'm installing 30 330 watt panels for a 9,900 watt system with at SE 10000 A inverter.

Jetskier

The following is a link to the panel diagram if you need more info.  http://www.homedepot.com/catalog/pdfImages/d4/d4bdcd98-41db-4ec0-a757-990760ddc48d.pdf

JAZ140

tough one.. The panel may be 250 but its up to the bus bar rating.  The buss is most likely only 200amps allowing a 40amp back feed...BUT..   I would think this would be classified as a center tap panel that does not allow the 20% rule. 

SE 10000 is capable of 41.6 amps so X1.25 52.08!  That sucks...  Just shy. May be able to convince the AHJ that the 50 amp slot is ok with a 60amp breaker because the inverter is only capable of 42 amps??   Looks like the 50amp slot is wired with #4 copper to that dedicated spot?  As long as all wire was sized for the 60 amp breaker I would not see a safety concern.. wonder why the panel is limiting it to 50 amps. What code are you under  2011 or 2014?