TVSS effectiveness?

[T.M.Haja Sahib]

Yes, and also the leads from the electrical system to the TVSS device.

That depends on the method of connecting the TVSS to the equipment it is intended to protect.

 

[petersonra]

A main factor in the failure of a TVSS to protect is its lengthy earth lead.The surge voltage across this lead during its operation applies to the device the TVSS is intended to protect with disastrous consequences.So one clue in the effective usage of a TVSS is to keep its earth lead as short as possible.

One of the interesting things about any surge protector is to apply Ohm's law to what is happening and see what the voltages are on some of the conductors we normally do not thing of as having much voltage drop. In some cases, depending on how your system is arranged, you basically end up using your GEC and/or neutral as a dynamic braking resistor.

You can get some interesting voltages on some conductors where you would not expect it.

All TVSS for use at service points I have seen have pretty short leads, but depending on where they are installed the effective lead length can be a lot longer.

The POU ones OTOH, can effectively have a very long lead length, which can expose both the ground and N conductors at the POU to some interesting voltage levels for a short period of time.