What is the difference between a series surge protector and a parallel one?
Series or two port surge protectors carry load current. So if you have a 500A service, the series surge protector would have to be designed to carry 500A. Series surge protectors are typically employed at the equipment level so the load current they would have to carry is not high, and they are usually small enough to fit within a cabinet or chassis. A series protector may also employ a series choke or inductor as part of its filter for EMI/RFI purposes. A parallel (or shunt) type surge protector does not carry load current. Also, failure of a series protector may mean that power is removed from the load is some cases. Failure of a shunt protector results in the protector being removed from the AC power line. AC power to the load is not interrupted but the load is now unprotected.
