What Bend said! Always have power to the battery system before attempt leveling or slide outs.
Unless your batteries are perfect, you'll overload and pop that breaker, which is good for about ten "pops".
I carry an extra, only about $25 on eBay.
When I bought my 2005 from All Valley RV in Acton, CA, the breaker was bypassed, but so badly with a loose connection, that I was able to figger it out and fix it.
The unit had never been sold, and was used for two years as a demonstrator to show off Georgetown's super features, i.e: backup alarm, theft alarm, dual pane windows, new big chassis, fiberglass roof, yadda,yadda, yadda.
By the time I got it, most of the bugs were gone.
I LOVE it!
2005 Georgetown 342DS XL, Full Banks Package
2005 Liberty Renegade 4X Toad
1989 Wrangler Sahara Toad
1984 19.5' Beachcraft i/o 5.o liter, 4-bbl (and you thought your Moho sucked gas!)
D/W Carole and Maggie the Teacup Lab (Black Chihuahua)