Great question, Dirk!
Both the 30A # HU24FR and the 50A # HU57FR Hughes Autoformers have built in surge protectors so you won't need to have a separate surge protector installed. If the Autoformers does have to deal with a surge situation we have a replacement piece so you can get the surge protection back without having to replace the entire unit:
- 30A # HU86FR
- 50A # HU26FR
Attached is a video showing how to replace the surge protector for your reference. view full answer...