We have had similar problems in the past with excel, every now & then the fuses blow, the problem with ours seems to be the fuse holders themselves, get too hot and then start to melt and the connectors burn out, we just order all new fuse holders every now and then and replace the lot, there quite easy to fit yourselves, just remove the top facia panel and they pop out.
I must admit tho, before the extracta excel we had a tcm 403, like Service master use to use, and although it was basic we never had an ounce of trouble with except for the odd vac motor every now and then, we even get it out now and use when the excel is not working,
what annoys me is when you phone extracta they say they've never heard of that problem before and it must be your fault, they never take responsibilty or give you the benefit of the doubt!
I'm on my third vac motor this year for the excel , and just think if it was something i was doing how come it doesn't happen to the other machines?
I'm not slagging of the machine or extracta, because i actually think they are good robust machines, but i do think they have a few problems going on that have just not been ironed out properly.
regards
steve