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TVSS – What is it? & Why do I need one?

What is a TVSS?

While much attention is given to the need to safeguard critical systems against power outages, the fact of the matter is, it doesn’t take a complete blackout to wreak havoc on sensitive electronic equipment. In fact, a wide range of power anomalies can cause significant damage to your equipment. One ongoing threat is dangerous voltage surges, which can result from culprits ranging from lightning strikes to the routine switching of large loads in data centers and process control environments.

Safeguarding equipment with a common type of power conditioning known as a transient voltage surge suppressor (TVSS) is a simple yet highly effective measure to help prevent damage to your devices. (And if you’re thinking you don’t need a TVSS because you already have an uninterruptible power system (UPS) in place, keep reading. One of the greatest misconceptions is that UPSs will protect equipment from lightning strikes or high-energy electrical spikes; they don’t.)

Installing a transient voltage surge suppressor helps to guard against these damaging voltage surges. TVSS accomplishes this surge protection with a switch that constantly monitors the AC voltage input and output waveforms. Although nothing happens under normal operating conditions, when the TVSS senses a voltage that exceeds operating parameters, it will clamp the voltage to a safe level before it reaches the equipment, with excess current diverted to the ground.

It is important to note that even with a TVSS installed, the force of a direct lightning strike is still capable of damaging sensitive equipment. While no device can guarantee complete protection against a such a hit, one type of TVSS known as a lightning arrester provides the best protection when installed at the main service entrance.

Don’t wait until it’s too late. Ensure your critical systems are safeguarded against voltage surges and spikes. Contact Unified Power today to learn more about our TVSS solutions and receive a free site assessment. Request a service or call our team for immediate assistance.

Four Types of TVSS

The UL 1449 standard specifies four different types of TVSS, which are determined by the installation location. Type 1 TVSS is usually installed on the line side of the service entrance, but is applicable anywhere within the power distribution system. Type 2 TVSS is installed on the load side of the service entrance, or branch panel. Type 3 TVSS ― which usually consists of power strips, receptacles or plugs ― is installed near the protected equipment. t is known as surge protection module. Finally, Type 4 provides protection to servo motors, PLCs and other devices used in industrial applications.

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Transient voltage surge suppressor, surge protective device, voltage surge suppression, surge arresters, lightning arresters, arc flash protection, surge monitors, overcurrent protection … and the list goes on. With so many potential product lines, it can be difficult to know which devices are the same and which are different ― making it even more challenging to determine the optimal protection device for your electrical equipment. Worse still can be deciphering the extensive range of acronyms that encompass the terminology of power distribution and critical power protection devices, leaving you to wonder if you’re trapped in a steaming pot of alphabet soup. But don’t despair; we break it down here.

Transient voltage surge suppressor (TVSS) and surge protective devices (SPD) both refer to a piece of equipment that can protect low-voltage electric systems from damaging transients, spikes or surges. The term TVSS tends to be more popular in countries that adhere to UL standard, such as the U.S. and Canada. Although TVSS devices have always belonged to a larger family of surge suppression devices known as surge protective devices, or SPDs, beginning with UL 1449 3rd Edition and the 2008 National Electrical Code, the term SPD formally replaced the labels of both “TVSS” and “Secondary Surge Arrester.”

So if TVSS and SPD are the same devices, what about another commonly tossed-around acronym, TVS? While they sound similar, it is important to note that TVSS and TVS are not interchangeable terms. TVS is the abbreviation for transient voltage suppressor, which is an electrical component or diode that serves the purpose of a surge suppressor. TVS is one of the three most common elements used to manufacture TVSS devices, with the others being MOV and GDT.

Who Needs a TVSS?

Damaged electronic equipment. An increased need for service calls. Unexplained system shutdowns or errors. If you’re experiencing any of these symptoms, transient voltages may be the culprit. Transient voltage surge suppressors can be deployed with any equipment that connects to electricity, telephone lines or computer data/communication lines, including computers and peripherals such as printers, monitors, speakers, fax machines and modems; PABX and communication systems; entertainment components; medical devices such as surgical instruments and scientific equipment; security systems; and other electrical equipment.

One of the most common misunderstandings about UPSs is they will protect equipment from lightning strikes or high-energy electrical spikes. While this may be true for some smaller single-phase units, the vast majority of medium to large three-phase UPS models do not provide internal lightning or TVSS protection. Because of this, it is critical to install a TVSS at the electrical panel feeding the input power to your UPS. Both the rectifier and bypass inputs to the UPS require protection.

Let Unified Power Help You Install a TVSS for Your UPS System

If you’re unsure whether or not you have existing TVSS units, or which type of TVSS is best for your particular environment, Unified Power can help. Experts in power quality ― including TVSS products and other power management solutions that safeguard sensitive electronics against transient voltage surges and other common power anomalies ― we have designed, specified and installed thousands of UPS systems with TVSS at the source. Contact us today to learn more about your options and how you can optimally protect your equipment from lightning strikes and surge currents.

If you are not sure if you have a TVSS, or need further information please contact Unified Power to learn more about your options and how you can protect your equipment from lightning and power spikes.

At Unified Power, we have designed, specified and installed thousands of UPS systems with TVSS at the source.

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