If this isn't the right place to reply to Mixerman, don't beat me up, since this is my very first post. I just found otherpower. But, I have been working an HF 45 watt kit to death since November, 2007 and I feel I can contribute here.
I can see from the earlier posts that you probably got your basic question answered. That is: the 4 amp fuse is only there to protect the circuitry within the controller from damage. And it only protects the front panel jacks.
If you want to draw a lot of power, get it right from the battery.
If you want to see what I think about this system, goto
www.spaco.org and click on the "solar energy" link. It's all there except for my "Final Report", which I just posted yesterday to a.c.photovoltaic.
The thing I want to add here is that I think the Harbor freight controller (the latest one takes ATC-4 fuses, by the way) is a pretty darn good machine and I'd enjoy arm wrestling with anybody on that issue.
On the other hand, I can't get any more than 30 watts out of the panels, no matter what I do.
Oh, yeh---- NEVER move any wires around on the controller while the panels are generating voltage!!!!!!!!
If you want to see the "Final Report", email me direct or ask me to post it here.
Lastly, I did notice that you wrote "Harbor Fright" in your subject. I just want to say here that they have been great about replacing the failed controllers, both at my local store and later through the internet operation.
I am:
Pete Stanaitis (on his 4th controller, which has the battery voltmeter on the front, and works just fine),
spaco@baldwin-telecom.net