If the surge is momentary and the volts settle back down I suspect that you are using a Xantrec C series controller. These are a bit slow responding, something that Hugh has mentioned often but seems completely unknown to everyone else.

If you have any other controller or the voltage doesn't come back down then there may be other issues that can't be resolved without more details.

It will also trip sometimes with only one 20watt load on it.

I suspect the problem is I am only charging two golf cart batteries at a time. (only 220 amp hours total).  
I am still learning myself, but was wondering if it would trip the inverter if I was charging a BIGGER battery bank like 500AH or more??

I can't imagine everyone else having this problem esp/w a whole house set-up. I only have a small system right now.  

I actually have to charge two sets of batteries seperately since one set is older and less voltage after final charge.  I Hook the two sets together at night to watch hours of TV and then disconnect the two sets so I don't sulfate the new batts over time from the old ones dragging them down all the time.

I just found that there is a discrepancy with the C60 I got and the booklet that came with it. I bought it new, but the book shows the voltage range for Bulk stage from 15-17 volts, but on the circuit board of the C60 it says the range is from 13-15 volts.  
Also, the book says that the float range is 14.5 - 16.5 volts, but the circuit board on the C60 itself says the float range is 12.5 - 14.5 .

I had my Bulk set at 13.5V according to the circuit board itself, and the float at only 12.7v.
But I suspect my main problem is my dump load not being big enough wattage.

For a dump load I have been just using one 12v (200watt) car heater (one element) with a separate fan.  I like doing 'heating experiments'. (200W is about the max of my power generation right now)

  According to my meter, it is 2.4 ohm. Thats higher than I had thought.

Therefore I see what I need to do. Parallel another heating element to get it down to around one ohm.

I suspect the poster may want to do what Flux suggested and reduce the bulk setting down, maybe to 14v and see if that does the trick.  On a windy day, you probably have plenty of extra power going to the dump load anyway.  

Any way i did a little more investigating last night, It is because i have a few light bulbs in parallel to my elements. reading in a board i came across a posting that said that lights have a much more high current pull until they heat up. so i went and purchased  another heating element. maybe someday i will actually put them in a tank, but not until i move to Colorado in a few weeks. Thanks for all of the postings you all are a huge help

I've forgotten how many people have had problems with commercial charge controllers and in my opnion the DIY approach is always the best way. If your not electronic's savvy I can do a screendump pic showing you how to build one using veroboard.