TVSS Mitigation and Installation

Proper use of TVSS equipment will help protect you from all transients except a direct lightning strike. It is a good idea to install TVSS devices to protect all your sensitive electronic equipment. Here are a few symptoms you can look for to determine if you have had a transient condition:

• Damaged electronic equipment such as computers, fax machines, televisions and communications equipment.
  
• Increased service calls on electronic equipment in your facility.
  
• Unexplained system shut downs or errors.

How Does It Work?
TVSS equipment acts as a voltage sensitive switch. It constantly monitors the voltage. Under normal conditions nothing happens, but when the voltage difference between the power source and the protected line gets high enough, the switch closes and diverts the transient away from your equipment. This switching voltage is often called the "clamping voltage" of the TVSS.

There are two basic varieties, plug-in and hard-wired . Plug-in TVSS units are plugged into wall outlets to protect specific appliances or electronic devices. Hard-wired TVSS units are used as a primary defense for the entire building or to protect sensitive circuits and are installed by an electrician at your service entrance or in sub-panels within your building.

Plug-in TVSS
Plug-in TVSS equipment should be installed between the outlet and the sensitive electronic equipment to be protected. If the TVSS has several outlets, several pieces of equipment can be plugged into it. If it is a single duplex outlet in the wall, a UL-listed multiple outlet device can be safely plugged into it to allow protection for more equipment. Watch the power ratings of the equipment you are protecting in this manner, so that you don t overload the circuit.

Never plug large motor loads into the same TVSS as sensitive electronics. These include fans, window air conditioners, copiers and some laser printers. Locate the TVSS where it can be easily accessed and, if possible, seen. For best results, plug-in TVSS equipment should be used with a high voltage hard-wired TVSS device located in your main electrical panel. Be sure to follow the appropriate guidelines for selecting a plug-in surge protector, and remember to select protectors with telephone, coax, or other additional protection to guard against "back-door" surges, if necessary.

Hard-wired TVSS
Hard-wired TVSS equipment can be used to protect an entire building. Hard wired equipment is installed by a qualified electrician at the main service entrance panel, or in a sub-panel to protect sensitive circuits connected to it. When installing the unit, the lead from the power panel to the TVSS should be kept as short and straight as possible. Excessive length or sharp bends will inhibit its ability to operate. Locate the TVSS where it can be easily accessed and, if possible, seen.

Hard-wired sub-panel TVSS equipment should be used in conjunction with a high energy TVSS device in your main service entrance.