Originally Posted by Stormrider151
My apologies to Progressive Industries. With that I'll have to give them my business and get the EMS-PT30C. It looks like it will cover everything well and isn't that bad price wise.
It does not cover everything. In part because a surge can be a low voltage, a high current, a low current, or a high voltage. Other anomalies include reversed polarity, open neutral, harmonics, frequency variation, power factor ... and others may exist.
That Progressive will protect from fewer and typical anomalies seen in a camp ground. For example, low voltage (ideal for electronics) can be harmful to motorized appliances (refrigerator, air conditioner). Open neutral can create potentially harmful high voltages. None of these are surges - except in a world where layman are taught by sales brochures; want to be told what to buy without first learning the threats. So yes, some of the more common anomalies are addressed by the more expensive Progressive units.
Another anomaly is a surge. These cannot be stopped or blockes - as so many buy protectors to do. These are averted when a surge protector is as close as possible to the pole's earth ground. (Those would be water proof.) That separation between protector and trailer increases protection. So, are you concerned for protection from surges such as lightning? These may occur once every seven years. But are so destructive.
Again, know each threat before a best solution can be provided. So many do not know what a surge is. Many if not most surge protectors do not protect from surges that really are surges. For example, a floating ground is not a surge. But many buy a 'surge protector' to protect from that anomaly.
Usually our help line people get frustrated by consumers who do not first learn the threats - but want a solution. In your case, the help line guy was probably sending you to an electrician to teach some simple electrical concepts that everyone should have learned after high school. Appreciate his frustration when you cannot first define which anomaly is a concern.