Originally Posted by gljurczyk
2440 Joules for the 30 amp 34830 model# 3850 Joules for the 34850 model#. If you want to run your electronics including circuit boards at 102 volts be my guest.
Irrelevant here are those fears. As tenttotrailer notes, "Not sure which company is best ... but you need protection for your investment." Even a manufacturer's name does not answer that question. Relevant is which anomaly must be averted. That also means specification numbers.
Electronics damage due to low voltages is only from fear and urban myths. Low voltage is only a threat to motorized appliances. In fact, one international design standard defines all low voltages in all capital letter: "No Damage Region". Most who fear have learned from hearsay. Relevant is which appliance needs protection from which anomaly.
As davel1971 notes, "the one you are looking at will not protect you from what is probably the most likely thing you can experience. Low or high voltage." A high or low voltage is also called a surge. Other and completely different anomalies are also called surges. 'Surge' is a vague and subjective term. The 'surge' of greatest concern here is high or low voltage.
Other anomalies are floating safety ground and reverse polarity. Those are irrelevant to appliances; are about human safety. That protector cannot even detect a defective earth ground. Each type protector is so completely different than each must be defined in terms of what surge it actually protects from. Probably the most likely one might experience is low or high voltage.
Even thousand joules are near zero protection. Destructive surges can be hundreds of thousands of joules. A thousands joules protector cannot absorb that energy. This is a completely different anomaly also called a surge.
To protect from that anomaly, a protector must be located as close to the pole as possible (ie within feet). Separation between a protector and trailer then increases protection. No protector protects from that anomaly. For this anomaly, a connection to (ie as short as possible) and a pole's earth ground define protection. This type surge is extremely rare.
Protection is defined by which 'surge' must be addressed. Low and high voltage are not problematic to electronics; are problematic to motorized appliances (ie air conditioner, refrigerator). Protection of all appliances from a completely different anomaly (also called a surge) means a protector must be located low impedance (within feet) of the pole's earth ground.
Different protectors are for completely different anomalies. Each is discussed in terms of what it does (ie specification numbers). Even a manufacturer's name says less.