Protecting your computer equipment from surges

Lightning bolt

It’s a stormy day and suddenly there’s a nearby lightning strike. Later, you try to turn on your computer and it doesn’t work. Nor does your fax machine. You’re confused because you know they’re plugged into an AC surge protector, which should protect them from lightning—right? Well, not in every circumstance.

Damage to office equipment is a residual effect of many storms that involve lightning. Taking precautions before a storm strikes can help reduce possible losses to equipment such as computers, fax machines, printers, and telephone systems.

According to the National Lightning Safety Institute, damage from electrical surges is one of the leading causes of electrical equipment failure. The most obvious source is from lightning, but surges can come from a variety of other sources, too. Power surges may come from external sources like lightning, and internal sources like fax machines, copiers, and air conditioners.

One overlooked source of power surge damage comes from failing to protect sensitive electronic equipment connected to telephone/fax lines, cable or satellite systems, and local area network coax cable. Power surges can quickly travel along these sources of electric current, damaging your equipment. You can increase your chances of avoiding costly repairs and downtime by adding a surge protection device to these systems, as well as to your AC plug. Make sure the surge protection device is properly sized for the system it will protect, and that it is properly installed.


Some additional recommendations to protect your computer equipment from surges are:

  • Install your surge protection device as close to the equipment being protected as possible.
  • Keep cable lengths short and as straight as possible to minimize the resistive path of the circuit to ground.
  • Make sure your connection to your surge protector is solid by pushing the plug completely into the socket.
  • Only purchase surge protectors that are equipped with indicators that show the circuit is grounded and the unit is operating properly, allowing for easy inspection.
  • Consult with a licensed electrician to ensure that your electrical distribution system is grounded correctly.
  • Check with your insurance agent or representative to confirm you have proper coverage for your computers and laptops before a loss occurs.
Lightning bolt
This document is intended for general information purposes only, and should not be construed as advice or opinions on any specific facts or circumstances. The content of this document is made available on an “as is” basis, without warranty of any kind. This document can’t be assumed to contain every acceptable safety and compliance procedures or that additional procedures might not be appropriate under the circumstances. Markel does not guarantee that this information is or can be relied on for compliance with any law or regulation, assurance against preventable losses, or freedom from legal liability. This publication is not intended to be legal, underwriting, or any other type of professional advice. Persons requiring advice should consult an independent adviser. Markel does not guarantee any particular outcome and makes no commitment to update any information herein, or remove any items that are no longer accurate or complete. Furthermore, Markel does not assume any liability to any person or organization for loss of damage caused by or resulting from any reliance placed on that content.

*Markel Specialty is a business division of Markel Service, Incorporated, the underwriting manager for the Markel affiliated insurance companies.
Was this helpful?