Re: Belkin Surgemaster : How does it operate ?

w_tom wrote:
On Dec 8, 10:52 pm, Paul <nos...@xxxxxxxxxx> wrote:
Generally speaking, a breaker would trip, if something on the load
side exceeds the rating (15A or whatever). If a MOV clamps the line,
and continues to clamp after the transient disappears, then the
breaker (or another fuse device inside), may open.

MOVs are intended to protect from surges. A surge is by definition a very short duration event. Very unlikely a breaker would trip from clamping a surge. Breakers are to protect from too much load plugged into the strip. I suspect the breaker was switched off.


In some surge strip designs I've read about, the MOV devices are supposed
to have some free space around them. When they blow (fail while protecting
your equipment), they need room so the exploding bits can get out of the
way.

As noted below, for many years plug-in suppressors have been required by UL to have thermal disconnects for failing MOVs. In the US, only listed suppressors should be used.


Surge protectors do not operate as posted. First, breaker will not
open due to MOV clamping. MOVs inside plug-in protectors are a fire
threat. Therefore MOVs have their own thermal fuse to disconnect only
MOVs on a tiniest current - to completely disconnect MOV protectors
leaving a surge connected to the appliance. Oh! MOVs disconnect fast
and early? Yes, because the protector is typically undersized and
because the disconnected MOVs (what the status light reports) will get
the naive to buy more undersized protectors.

“Undersized” and “disconnect early” - only with an incompetent manufacturer. A competent manufacturer carefully matches the protection to the MOVs.

For reliable information on surges and surge protection try:
http://omegaps.com/Lightning%20Guide_FINALpublishedversion_May051.pdf
- "How to protect your house and its contents from lightning: IEEE guide for surge protection of equipment connected to AC power and communication circuits" published by the IEEE in 2005 (the IEEE is the dominant organization of electrical and electronic engineers in the US).
And also:
http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf
- "NIST recommended practice guide: Surges Happen!: how to protect the appliances in your home" published by the US National Institute of Standards and Technology in 2001

The IEEE guide is aimed at those with some technical background. The NIST guide is aimed at the unwashed masses.


Why must MOVs disconnect so quickly? 'Scary pictures' demonstrate a
problem with some current technology (and undersized) surge
protectors:
http://www.hanford.gov/rl/?page=556&parent=554

w_ can't understand his own hanford link. It is about "some older model" power strips and says overheating was fixed with a revision to UL1449 that requires thermal disconnects. That was 1998. w_ has no links that say overheating is a problem under the UL standard in effect since 1998.

In one zerosurge.com picture, MOV (the protectors) are completely
removed. Status light says protector is OK.

This is indeed a serious problem if you live in an area where thieves steal MOVs out of surge suppressors. Check with your local police to see if a MOV theft ring is active in your area.


Status light can only
report a defective protector (only due to catastrophic, unacceptable
failure) AND cannot report a good protector.

MOVs fail by conducting at too low a voltage resulting in thermal runaway. That causes the thermal disconnects to open. Status lights indicate if the MOVs have been disconnected, and conversely if the MOVs are OK.


Second, MOVs must never protect by 'blowing'. That catastrophic
failure, common in plug-in protectors

The NIST guru on surges has written "In fact, the major cause of TVSS [surge suppressor] failures is a temporary overvoltage, rather than an unusually large surge."

In fact a plug-in suppressor with high ratings is very unlikely to fail. That is why manufacturers can offer warranties on not only the suppressor but connected equipment.

Better is to undersized a
protector the naive will promote myths. If a protector was effective,
the myth purveyor would not know a surge even existed and would not
recommend that protector to friends.

w_ appears to believe all plug-in suppressors are undersized. Plug-in suppressors with very high ratings are readily available and relatively inexpensive.


Any protection attached to its power cord is already inside the
computer and other household appliances. Protection already inside
the appliance makes a small surge irrelevant. But that same 'so
small' surge catastrophically and unacceptably destroys an undersized
protector - as statud light indicates.

Complete nonsense.

Energy that was not stopped by
three miles of sky must be dissipated somewhere. An effective
protector connects a surge *to* protection. An effective protector
connects that energy to earth where surge is harmlessly dissipated.
But if the protector has no dedicated earthing wire, then where does
that energy get dissipated?

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. The IEEE guide explains plug-in suppressors work by CLAMPING the voltage on all wires (signal and power) to the common ground at the suppressor. Plug-in suppressors do not work primarily by earthing (or stopping or absorbing). The guide explains earthing occurs elsewhere. (Read the guide starting pdf page 40).

Note that all interconnected equipment needs to be connected to the same plug-in suppressor, or interconnecting wires need to go through the suppressor. External connections, like phone, also need to go through the suppressor. Connecting all wiring through the suppressor prevents damaging voltages between power and signal wires. These multiport suppressors are described in both guides.


How to identify an ineffective protector? 1) It has no dedicated
earthing wire. 2) Manufacture avoid all discussion about earthing.

With minimal reading skills w_ could find in the IEEE guide that plug–in suppressors work primarily by clamping, not earthing.

The question is not earthing - everyone is for it. The only question is whether plug-in suppressors work. Both the IEEE and NIST guides say plug-in suppressors are effective. Read the sources.

There are 98,615,938 other web sites, including 13,843,032 by lunatics, and w_ can't find another lunatic that says plug-in suppressors are NOT effective. All you have is w_'s opinions based on his religious belief in earthing.

Never answered:
- Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors?
- Why does the NIST guide says plug-in suppressors are "the easiest solution"?

–
bud--

.

Relevant Pages

  • Re: Belkin Surgemaster : How does it operate ?
    ... Very unlikely a breaker would trip from clamping a surge. ... UL to have thermal disconnects for failing MOVs. ... Status light says protector is OK. ... This is indeed a serious problem if you live in an area where thieves steal MOVs out of surge suppressors. ...
    (alt.comp.hardware.pc-homebuilt)
  • Re: Does as GFCI give you some surge protection?
    ... IEEE paper - also warns of same damage "even when or perhaps because, ... of a properly designed surge reference equalizer [mulitport ... Martzloff consistently says plug-in surge suppressors ... a second multiport protector located at TV2 is ...
    (alt.home.repair)
  • Re: How to ground electric outlets over a slab?
    ... MOVs are connecting devices to earth ground. ... protector, they are in ADDITION to the point of entry protector. ... That dumps most of the surge energy to earth. ... They are not a surge protection element in the vast majority of plug-in or service panel suppressors. ...
    (alt.home.repair)
  • Re: How to clean up mains power?
    ... François Martzloff was the surge guru at the NIST and wrote the NIST guide and has written "In fact, the major cause of TVSS failures is a temporary overvoltage, rather than an unusually large surge." ... Surge suppressors are almost all based on MOV voltage clamps. ... UL requires that MOVs that fail be disconnected to protect from overheating. ... The IEEE guide describes at length how, for a plug-in suppressors, the protected load may be connected across the MOVs and be disconnected with the MOVs if they fail, or may be connected directly to the incoming line. ...
    (sci.electronics.equipment)
  • Re: surge protection for cart
    ... "How to protect your house and its contents from lightning: IEEE guide for surge protection of equipment connected to AC power and communication circuits" published by the IEEE in 2005. ... Plug-in suppressors in the US have MOVs from H-G, N-G, H-N. ...
    (rec.arts.movies.production.sound)