L Ectro wrote:

Pete C. wrote:
clifto wrote:

Pete C. wrote:
w_tom wrote:

Common mode surges are a most typical source of electronics damage.

useless bogus blather deleted

There you go again with your nonsense.

Care to explain how a common mode surge can damage a device that
has no ground connection?

The same way a person that has no ground connection can plug his
finger into the hot and not the neutral or ground contact in a
socket and still get electrocuted. When you say the device has no
ground connection, what you really mean is that it has no *obvious*
ground connection.

And even if your device is a hundred million ohms from ground, it
may be insulated from ground by something that will punch through
when a 5,000 volt common-mode surge hits the device.

--
Asking Iran and Syria to help us succeed in Iraq is like your local
fire department asking a couple of arsonists to help put out the
fire. -- Joe Lieberman

I already covered that in another reply. A device with no ground will
be unaffected by a common mode surge up to the point of insulation
breakdown through for example, the plastic case of the device, the
wood table it's on, the carpeting under the table, etc. Basically a
very close lightning strike which no affordable protection device
will be able to protect against.

Pete C.

Actually, switch gaps usually get jumped first.

Example:

A common mode surge comes in along the 2 wire power cord to line lump
powering a laptop computer sitting on a wooden table. The laptop has no
connections to any other device i.e. WiFi network. Unless the surge is
of a large enough magnitutde to punch through the insulation of the
devices in question there should be no damage.

Pete C.