Good question. I did a survey in 2004, and determined that the specifications of various surge protection was different from what the components were rated for, so this answer is unknown. I have extensive electronics background, and I stumbled when trying to compare specifications. When you buy from switchgear manufacturers, the cost is higher than what HVAC equipment costs, but when compared to the MOV surge electronics the price is much higher. Based on what I found, the protection should be included in new switch gear at no additional cost, but this will never happen.