What is a whole house surge protector?
A whole house surge protector is a device connected at your service panel that provides protection from ‘big’ surges such as lightning strikes. Most residential houses are supplied with two 120V legs and so a whole house surge suppressor designed for such an installation would typically have ‘four mode’ protection: live 1-neutral, live 1-ground, live 2-neutral, live 2-ground. Some products add additional live1-live 2 and neutral-ground protection to become a ‘six mode’ device. Commercial facilities may receive ‘three phase power’ which will require a different device.
The maximum surge that can be expected at the service entrance is a C3 combination wave of 20kV, 10kA. Whilst lightning strikes can be 200kA this type of current does not reach the service entrance due to operation of utility surge arrestors, arc over to ground at the service entrance and insulation failure. What high kA rated surge protectors typically give you is longer lifespans, though much depends on the SPD and the protection mechanisms it uses.
Basic whole house protectors are sold at the big box home improvement stores. We, however, recommend the Environmental Potentials EP-2050 which is a more sophisticated device that has the benefit of providing a first tier of noise reduction for your system.