Frequently Asked Questions on TVSS. 

  • Protection Questions
  • Performance Questions
  • What size fuse can the Strikesorb Suppressor module be used with?


Protection Questions

Q: I have a UPS system that protects against surges, why would I want another form of protection?
A: A UPS is not intended to give surge protection!! It is to increase the reliability of the supply in case of power failure.

Q: I don't have a problem with surges, everything is isolated, why do I need TVSS?
A: A UPS actually makes equipment generated surges worse. This is due to the impedance looking back into the UPS being much higher than the power system. As a result equipment generated surges get reflected around the plant until the weakest point absorbs them. The front end of a UPS is vulnerable to incoming surges. It is protected by a very small varistor. UPS units often drain their batteries after a surge as the input circuit and fuse usually fail. You get the time the output stays up to repair the input.

Q: Since your unit is up stream how does it protect equipment in our plant from surges generated in the plant? We need a device close to the equipment being protected. If I install one at my incoming service, is that all I need to protect everything?
A: First protect your plant at the input. Second identify and put surge arrestors on the equipment that generates surges (motors and capacitors). Third identify the most vulnerable loads and protect them individually. Transients can circulate via many paths it is best to stop them at source.

Q: I don't have a lightning problem, why do I need such a robust TVSS unit?
A: Lightning is the most dramatic, not the most frequent power problem. Switching transients - from the utility grid, from neighbor's equipment, or even from in-house elevators, refrigeration, or other electrical equipment - result in damage and destruction. Switching transients threaten your hardware and software on a daily basis.

Q: Will this survive a lightning strike?
A: Yes, it will absorb lightning to the level absorbed into a power system.


Performance Questions 

Q: Does Rayvoss provide EMI filtering?
A: Yes, on special models developed for particular applications that require EMI filtering.

Q: What is the difference between the 4 and 7 module TVSS unit for 3Y applications?
A: A 4 module unit provides protection phase to ground and neutral to ground. Phase to phase protection is provided via ground. A 7 module system provides extra protection between phase to neutral, recommended for sensitive loads or for installations with frequent line surge problems.

Q: How quickly does Strikesorb react to a surge?
A: The TVSS "reaction time" metrics are measured by voltage let-through or
SVR. When the amplitude and rise time of a surge reach a level that threatens equipment, Strikesorb responds with the lowest let-through voltage to protected equipment.


What size fuse can the Strikesorb Suppressor module be used with?

Strikesorb can be used after a 1200Amp Class L (or less) fuse at 200kA prospective fault current. At 100kA prospective current, an 800 Amp class L (or less) is acceptable. Other fuse classes would be limited to:

  • any class J;
  • any class G;
  • any class T(300V);
  • any class RK1;
  • 400A for class RK5.