Transient voltage surge suppression (TVSS) is protection that guards an electrical system and its connected equipment from transients, brief, high-voltage spikes that can damage electronics and equipment, by diverting or limiting the surge energy. The technology is now more commonly referred to as a surge protective device (SPD), and it is widely used in commercial and residential buildings to protect against surges from lightning, utility events, and internal sources. Understanding what it does helps businesses protect sensitive and valuable equipment.
Here is what transient voltage surge suppression is.
What transients are
A transient (or surge) is a brief, sudden spike in voltage far above the normal level, lasting only a fraction of a second but capable of damaging equipment. Transients come from sources such as lightning, utility switching and events, and internal sources like large equipment switching on and off. Though brief, these spikes can degrade or destroy sensitive electronics and shorten equipment life, which is the problem surge suppression addresses.
What TVSS does
Transient voltage surge suppression protects against these spikes by diverting or limiting the excess surge energy so it does not reach and damage equipment. When a transient occurs, the device clamps the voltage, shunting the surge energy (typically to ground) and limiting the voltage that passes through to the protected system. In effect, it absorbs or redirects the spike, keeping the voltage the equipment sees within safer limits.
TVSS is now called SPD
The term TVSS has largely been replaced by surge protective device (SPD), which is the modern terminology in codes and standards. They refer to the same basic function, protecting against transient surges. So if you encounter both terms, TVSS and SPD, they describe surge suppression equipment, with SPD being the current standard term. SPDs come in different types for different points in the electrical system.
Where it is applied
Surge suppression can be applied at different levels for layered protection:
- At the service or panel, protecting the whole building from larger surges entering the system
- At subpanels or specific equipment, adding protection closer to sensitive loads
- At point-of-use, such as plug-in protection for individual devices
A layered approach, with protection at the panel and closer to sensitive equipment, provides the most effective defense, since whole-building protection handles large surges while downstream protection catches what gets through.
Why it matters
Surge suppression matters because modern businesses rely on sensitive, valuable electronic equipment that transients can damage. A single large surge can destroy equipment, and repeated smaller surges can degrade it over time. Protecting against surges helps safeguard computers, electronics, controls, and other equipment, reducing downtime and replacement costs. For a commercial building, surge protection is a worthwhile investment in equipment reliability, which a licensed electrician can design and install.
Transient voltage surge suppression (TVSS), now commonly called a surge protective device (SPD), protects electrical systems and equipment from transients, brief high-voltage spikes from lightning, utility events, and internal sources, by diverting or limiting the surge energy. Applied in layers from the service to sensitive equipment, it safeguards valuable electronics from damage. For commercial buildings relying on sensitive equipment, surge protection is a worthwhile investment that a licensed electrician designs and installs.
Stella Electric designs and installs surge protection for businesses across the Baltimore area and throughout Maryland, with flat-rate pricing and no overtime charges. If you want to protect your equipment from surges, we can help. Financing is available on qualifying projects.
