Surge protection device（SPD） installation：
Locate the SPD as close as possible to the panel to be protected.
Drill and punch a hole within the SPD housing in an exceedingly position to attenuate the length of the connecting wires from the lugs of the SPD to the circuit breaker within the adjacent panel (or fused disconnect lugs).
Where possible, use a close-nippled connection with wires going on to the first breaker at the top of a panel. This ensures optimum protection of all loads connected to the panel.
Use AWG #10 stranded wire or larger (which is quickly available and simply installed) to connect between the SPD and therefore the breaker panel. Avoid sharp bends and excess length within the wiring. Neat and tidy installations aren’t necessarily the foremost effective ones. Short direct connections are best.
SPDs should be connected through an appropriately rated circuit breaker, not into the main lugs of the panel. Where circuit breakers are unavailable or impractical, a fused disconnect switch should be used to connect with the lines and facilitate servicing of the SPD.