What are the Regulations and Standards that Apply to SPDs?

There are six industry standards that apply to surge protective devices (SPDs), whether they are connected to the electrical system through a plug-in connection or hard-wired connection to the facility wiring. 

Click on a standard below to learn more:

• IEEE C62.41-1991
• IEEE C62.45-1992
• IEEE C62.48-1995
• NEMA LS 1-1992 (R2000)
• UL 1449 Second Edition
• NFPA 70 (NEC^® 2002) Article 285

Safety-Related Information

In addition to these standards, there are some important safety-related documents to be familiar with in the residential, commercial, and industrial environments.

Residential

All ac power SPDs for residential application should be UL 1449 Listed or Recognized. Non-listed or Recognized devices may create a fire or personal safety hazard. 

There are three basic types of SPDs for residential use:

1. cord connected/outlet mounted, 
2. hard wired to the breaker panel box, or 
3. an integral part of the receptacle. 

Cord connected devices may be installed by a layperson; types 2 and 3 should be installed by a licensed electrician. Residential surge protectors should self-monitor their status and indicate if a change in status occurs or a failure of the protector has occurred. The most common status-reporting feature utilizes indicator lights. In the event of a failure the unit should be disconnected and replaced immediately.

For additional information on residential surge protective devices, read “Surges Happen,” published by the National Institute of Standards and Technology (NIST) (www.nist.gov): Special Publication #960-6.

Commercial

All ac power SPD’s should be UL 1449 Listed or Recognized and installed on the load side of the main disconnecting device. Non-listed or Non-recognized devices may create a fire or personal safety hazard. Most commercial SPDs are hard wired to the facility electrical system. 

The primary function of the SPD is to limit surge voltage by diverting surge current to ground. A requirement for a good performing SPD is to install the device with a low resistance path to ground. 

Without a low resistance path to ground, the surge may go through an undesirable path inside expensive electronic equipment. The surge may also cause the SPD to overheat and fail prematurely. SPDs should be installed in accordance with the manufacturers installation instructions. These installation instructions should detail what size conductors to use and if the unit must be installed with an over-current device such as a fuse or breaker. If the installation instructions are not followed a hazardous condition may be created. 

• UL standards
• NEC

Industrial

All ac power SPDs should be UL 1449 Listed or Recognized and installed on the load side of the main disconnecting device. Non–UL approved devices may create a fire or personal safety hazard. 

Most commercial SPDs are hard wired to the facility electrical system. The primary function of the SPD is to limit surge voltage by diverting surge current to ground. 

A requirement for a good performing SPD is to install the device with a low resistance path to ground. Without a low resistance path to ground the surge may go through an undesirable path inside expensive electronic equipment. The surge may also cause the SPD to overheat and fail prematurely. SPDs should be installed in accordance with the manufacturers installation instructions. These installation instructions should detail what size conductors to use and if the unit must be installed with an over-current device such as a fuse or breaker. If the installation instructions are not followed a hazardous condition may be created. 

• UL standards
• NEC

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