Why surge protection is a must

Surge protection is a must

Installing SPD’s (Surge Protection Devices) on your project keeps your electronics and sensitive equipment from getting damaged in a power surge.  Power surges usually happen during storms where there is a sudden massive spike in electric system current.  They only last about a fraction of a second, but can cause costly damages to any outlets or plugged-in appliances.  This is due to the power surge overloading the circuits connected to your electrical system.

How to Properly Size Surge Protective Devices

There is very little published data or even recommendations on what level of surge current (kA) rating should be used in the different locations. The Institute of Electrical and Electronics Engineers (IEEE) provides some input on what surge ratings are and how to interpret them but does not publish recommendations.

Once it has been determined where the SPD units are to be installed, help in determining the surge rating (level of protection) can be found by referencing the panels Ampere rating (see chart below)

Types of SPD Locations

  • Type 1 is intended for permanent application at the service entrance. It can even be before the main disconnect. A UL1449 Type 1 device can be installed on the primary of buildings or the 1st disconnect.
  • Type 2 is intended for installation on the load side of the main entrance panel. Type 3 is for specific devices, referred to as “point of utilization” in the standard.


The primary purpose of the surge protective device is to shunt and supress the transient voltages that are being introduced into the system to an external source, usually ground.

Click to visit our Manufactures Solutions for SPD’s https://www.nvent.com/en-us/erico/solutions/surge-protection

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