I had similar problem as rewire. I called Firex and they explained that when the Power co. would shut down 1 of there gen. it woyld cause spikes and noise ,usally late at night or early morning when demand was down. This would set the units off. I thought, yea right! But I was willing to play along. So, I installed a surge breaker in the panel. Guess what it worked I have not had a problem since.

Choose your customers, don't let them choose you.