I get asked frequently, “What’s the difference between the Progressive Industries SSP’s and EMS units? And the simple answer is this. Both the SSP and EMS models have surge protection and both models indicate if the pedestal is wired correctly and that's about all these two have in common. The EMS models not only indicate whether or not the pedestal is wired correctly, in the event there is a problem with the pedestal power, it also prevents this bad power from coming into your RV, until it is corrected.
The EMS models are a full electrical protection device, meaning they have high/low voltage protection, reverse polarity protection, open neutral protection, open ground protection, AC frequency protection, accidental 220V protection, and previous error codes. No other surge protection devices currently available on the market offers ALL these features.
So the differences in the units are simple. It’s all about convenience. But make no mistake all the Progressive Industries Surge and Electrical Protectors are made with the same high quality components.