the surge protector can protect the appliance work under the stable state,when the voltage is to ohigh or too low,the protector will cut off the voltage automaticlly,when the voltage recove the stable,the protector will start again  after the 3-5mins later.

Surge protector

KAB-15A

110/15A

OVER VOLTAGE:138V

UNDER VOLTAGE :92V

DELAY TIME:3-5MINS