Re: Long cat5 run question

I think ya'll aren't on the same page here, compounded by taking
quotes and references out of context.

There are two kinds of protection. The exact description may vary,
but its still a function of clamping the over voltage and shunting
the over voltage to ground, may it be done in a single device or with
two separate devices.

A MOS "surge protector" found in an outlet strip merely clamps
(or blocks) excessive voltage up to the point where the MOS device
fails. It offers virtually no lightning protection, per se.

A gas tube (or old style carbon block) arrestor shunts the over
voltage to ground. Its very robust, but if the voltage is not high
enough to arc over the arrestor (as in the leading edge of the spike),
then the "surge protector" will block it.

Either device if used by itself is not entirely effective.

bud-- wrote:
> w_ refers to plug-in surge suppressors as a ‘magic box’ because he
> can’t figure out how they work.

That was taken completely out of context.

w_tom wrote:
> Bud must post anything to avoid what is standard and fundamental to
> surge protection. A protector is only as effective as its earth
> ground. Earth ground - not a protector - provides protection.

Also taken out of context as Bud did indeed say proper earth grounding
was important.

bud-- wrote:
> w_ has a religious belief (immune from challenge) that surge
> protection must use earthing. Thus in his view plug-in suppressors
> (which are not well earthed) can not possibly work.

LITERALLY taken, an in-line "surge protector" won't need a direct
ground to block a transient spike, so earthing doesn't come into
the picture. Look at a MOS device, there are two wires attached to it,
neither one goes to ground, its KIND OF like the reverse of a Zener
diode that doesn't conduct until a threshold voltage is reached. Look
at a gas tube protector, it has three wires - where the "third" wire
is the grounded shell of the device.

.

Relevant Pages

  • Re: What are you using to protect your studio audio equipment from power issues?
    ... And also guide from the NIST: ... "Q - Will a surge protector installed at the service entrance be sufficient for the whole house? ... To limit that voltage you need a *short* wire connecting the cable/phone entrance protectors to the ground at the power service. ... According to the IEEE guide plug-in suppressors work primarily by clamping, ...
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  • Re: What are you using to protect your studio audio equipment from power issues?
    ... "Q - Will a surge protector installed at the service entrance be sufficient for the whole house? ... Service panel suppressors do not prevent high voltages from developing between power and signal wires. ... To limit that voltage you need a *short* wire connecting the cable/phone entrance protectors to the ground at the power service. ... A ground wire that is too long is illustrated in the IEEE guide starting pdf page 40. ...
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  • Re: Does as GFCI give you some surge protection?
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  • Re: http://h71000.www7.hp.com/?
    ... and the increased inductance wouldn't block a lightning induced surge. ... essentially an open circuit until the voltage goes past a knee in the characteristic curve, then the current rises very rapidly with increasing voltage. ... Ground potential to 'absolute earth potential' can rise thousands of volts, but phone, CATV and other signal wires are clamped to the grounded neutral through phone NID and CATV entrance block and all the wires ride up with the power conductors. ... Plug-in surge suppressors clamp the voltage H-N, H-G, N-G (and signal wires should go through the protector and be clamped to surge protector ground). ...
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