490 V Clamping Volt On MOV Surge Protector: Seems Very High; Is It ?

Hello,

Thinking of installing an Intermatic AG series surge protector across a
single 110 V line to help protect a circuiit board in a furnace.
This would be a modelAG2401

Clamping voltage is given as 490 V.

Seems awfully high.

Wouldn't most solid state devices such as PC circuit boards uprocessors,
etc. blow (well) before this level ?

Know of any similar point of service wired in units with a lower clamping
volt. ?

As always, much thanks for help and info; really appreciate it,
B.