Here’s the situation and then my question about the installation of a surge suppressor (Type 2) at an electrical sub-panel:
Leviton Surge Suppressor # 511250-1 (instructions: https://a89b8e4143ca50438f09-7c1706ba3fabeeda794725d88e4f5e57.ssl.cf2.rackcdn.com/spec_sheets/files/000/022/733/original/leviton-51120-1-installation-instructions.pdf?1442945250 )
Inside the Cutler-Hammer panel, there is a 70-amp double-pole circuit breaker with a pair of 4 AWG wires feeding another sub-panel adjacent to the Cutler-Hammer panel. A pair of 12 AWG wires run from the Leviton Surge Suppressor to the 70-amp double-pole circuit breaker. So, the 70-amp circuit breaker is double tapped (each terminal has a 4AWG wire and a 12 AWG wire). The breaker is not designed to be double tapped (and the wires are two different sizes too) This deficiency is not my concern here.
The Leviton installation instructions essentially says this: Select circuit breakers as close as possible to each service entrance lug. Twenty-Amp (20A) circuit breakers are recommended and may share surge protective device (SPD) and branch circuit leads. The breakers provide additional failure protection as well as an SPD connection and servicing disconnect.
Here’s my question: Is the 70-amp circuit breaker too big for the surge suppressor? Leviton states 20-amp “circuit breakers are recommended” but beyond this recommendation I do not see where Leviton requires or even mentions a minimum or maximum amperage rating for the circuit breaker. Does it matter?