PIR Alarm (490-0320A) Damage Faxback Doc. # 6621 Lightning damage is uncommon, but it can occur in electronic devices. A lightning strike near, or directly to, the power line might cause an excessive surge of voltage that can damage the alarm. If you are concerned about it or live in an area with frequent and/or severe electrical storms, we suggest that you purchase a surge protector (such as Cat. No. 61-2791 or 61-2786) to help prevent damage from power line surges. (br/all-07/11/94)