Bob & Lee
Many of us use an additional surge protector. Al uses one before the autoformer, so as to protect the autoformer. I think he told me the one on the autoformer is not sufficient in his opinion, and he does not want to have to send that autoformer back, a lot of work to send back, heavy, etc.
Here is the link to Al's page on his installation, I believe he addresses the surge protection there:
http://www.geocities.com/genieyorks/autoformer
Carol