Years ago when switch mode power supplies were really first being
introduced, we had a number of them installed in cubicles in a new
building. We were the first occupants. We started having a rash of
fires that were starting in the outlet receptacles in the cubicles.
The building management teams went looking for the causes and we found
no imbalance in the power distribution etc. The world looked good to
them. Still the fires continued (quickly extinguished at the source
mind you so they never spread) but it was observed that those offices
that were have a problem all had the equipment with the switch mode
supplies, and we quickly shuffled those around and the fires
quit. Neither the building engineers or we EE's had any clue about
harmonics on problems with these so that wasn't looked at and I can't
say for certain that was the reason, but after shifting the load of
the switch mode supplies around on different branch circuits the
problem stopped. So I certainly have my suspicions.
Gary
-----Original Message[Gary McInturff] ut -----
From: John Juhasz [mailto:[email protected]]
Sent: Monday, February 26, 2001 10:37 AM
To: 'Rich Nute'; [email protected]
Subject: RE: Harmonics -- WSJ opinion.
Rich,
I would think that you knew that this would generate discussion?
One comment of Mr Hunter's that stood out in particular was the
very last . . .
" . . . the only ones who benefit from the harmonic current
emission standard
are the European electricity distributors. They "avoid
investments in bolstering their networks against the
theoretical harmonics risk" at the cost of manufacturers
and consumers."
I would say that this senitment has been echoed by many compliance
engineers.
But the comment is 'non-technical' . . . can anyone in this forum
offer
any 'technical' arguments that would a)Back-up such a statement as
Mr. Hunter's or b) FAVOR the harmonic standard?
I like to give the benefit of the doubt that the standard was
created based
on sound technical evidence.
John Juhasz
Fiber Options
Bohemia, NY
-----Original Message-----
From: Rich Nute [mailto:[email protected]]
Sent: Monday, February 26, 2001 12:11 PM
To: [email protected]
Subject: Harmonics -- WSJ opinion.
With thanks to Ed Jones...
On Thusday, February 22, The Wall Street Journal Europe
published an interesting opinion on the harmonic current
emissions standard.
The opinion is by Rob Hunter, a lawyer and Chairman of
the Centre for the New Europe, a Brussels-based think
tank.
Mr. Hunter is quite critical of the EU "New Approach"
process. He says:
"In this procedure, the EU sets vague safety and
technical rules for everything from toys to super-
computers -- for example, toys shall be 'safe.' The
EU then delegates to private standardization bodies
the drafting of detailed requirements explaining
what the delphic rules mean."
"The supposed advantage of this New Approach is
twofold. For industry, it gets to write the detailed
rules applying to it. For the Commission, the New
Approach frees it from a burdenom task; it also
allows the Commission to claim that it has nothing to
do with writing the standards, and hence cannot be
held responsible."
"All this sounds quite above-board. It isn't."
"For one thing, the standards are not merelay a means
of proving compliance with the underlying legislation.
They actually determine the meaning of the law itself."
Mr. Hunter discusses "...the way these standard-setting
bodies can be gamed by industry insiders for advantage."
Mr. Hunter goes on to show how the New Approach process
allows the Commission to sidestep "...WTO laws prohibiting
'mandatory' product measures that create 'unnecessary
obstacles' to international trade."
Mr. Hunter's opinion goes on to show that the only ones
who benefit from the harmonic current emission standard
are the European electricity distributors. They "avoid
investments in bolstering their networks against the
theoretical harmonics risk" at the cost of manufacturers
and consumers.
Best regards,
Rich
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