Hello All:
Just a quick followup on our discussion about the short circuit tests:
I just received my copy of Issue 3 of GR-1089, and when I went to replace
Issue 2 I found a 1-page bulletin from Telcordia, dated December 1999, tucked
in the front of my Issue 2 binder. The bulletin specifica
All,
I agree with the concept that the short circuit is not always worst case. I
have seen many ITE power supplies shut down with a sc, but an output
overload lets the smoke out.
One problem with a trace opening is the reliability of that opening in a
safe manner. When a certified fuse blows,
e.org
Subject: RE: Short circuit tests in GR-1089
Last I heard, and please correct me if not, was that Verizon had
rejected the new standards much to the chagrin of the rest of the industry.
Gary
-Original Message-
From: j...@aol.com [mailto:j...@aol.com]
Sent: Wedn
All -
In consideration of the proliferation of SMPS in electronic
equipment, it is not unrealistic to expect a simple
short-circuit might not meet the intent of GR-1089. While
many linear supplies will run indefinitely under sc, most
SMPS will go into hysteresis or shut down completely under a
s
owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Lou Aiken
Sent: Monday, November 25, 2002 10:38 PM
To: Ted Rook; j...@aol.com; <
Subject: Re: Short circuit tests in GR-1089
I'd like to add that the product need not operate correctly after a
fault
condition
Joe,
It is quite common for local filtering consisting of an inductor followed by
a capacitor to be added in the logic-level supply rail following an on-board
DC:DC converter when powering sensitive ICs. Often there are many such
filters on each card and it is not feasible to fuse each of them
i
; emc-p...@majordomo.ieee.org
Subject: Re: Short circuit tests in GR-1089
Hello All:
Many thanks to all who responded to my question about this requirement. Many
of the responses were quite interesting and persuasive, even though some of
them were directly opposed. I think that the expanded
In a message dated 11/27/2002, Marko writes:
> So what did you decide? Is a fuse blowing acceptable?
> I'm sure others would be interested as well.
>
Hi Marko:
So you want me to go on the record so I can get flamed? OK, here goes:
The revised text in Issue 3 of GR-1089 (kindly posted to th
Hello All:
Many thanks to all who responded to my question about this requirement. Many
of the responses were quite interesting and persuasive, even though some of
them were directly opposed. I think that the expanded description in the new
third edition of GR-1089 helps resolve most of the
jordomo.ieee.org] On Behalf Of Lou Aiken
Sent: Monday, November 25, 2002 10:38 PM
To: Ted Rook; j...@aol.com; <
Subject: Re: Short circuit tests in GR-1089
I'd like to add that the product need not operate correctly after a
fault
condition causes a fuse to open, it must only remain safe
3054
- Original Message -
From: Ted Rook
To: ; <
Sent: Monday, November 25, 2002 5:25 PM
Subject: Re: Short circuit tests in GR-1089
I'm not an expert on GR1089 but I think that your interpretation should
include careful consideration of what constitutes damage.
The operation o
I'm not an expert on GR1089 but I think that your interpretation should include
careful consideration of what constitutes damage.
The operation of a fuse or a circuit breaker is not damage.
That is normal operation.
What the specification is seeking to eliminate is overheating, explosion, loss
Joe,
I was going to suggest that you look into Issue 3 of GR-1089, but you have been
given the basics. I would suggest anyone who has to live with this standard,
get the new issue and spend a day or so to really look it over in detail.
There was a great deal of work put into clarifying inten
This was resolved a couple of NEBS conferences ago. All the main RBOCs
were present and they agreed that a fuse was a special case. The fuse
is designed to open, therefore operation of the fuse is normal and allowed.
This may be a semantic strech, but that's where the current NEBS
interpreta
iginal Message-
From: j...@aol.com [mailto:j...@aol.com]
Sent: Monday, November 25, 2002 1:25 PM
To: emc-p...@majordomo.ieee.org; t...@world.std.com
Subject: Short circuit tests in GR-1089
<< File: Short circuit tests in GR-1089.TXT >> Hello All:
I am hoping that so
eee.org; t...@world.std.com
Subject: RE: Short circuit tests in GR-1089
Joe,
The short-circuit test is to simulate the most prevalent source of telecom
disruption: the back-hoe.
When a buried cable is inadvertently cut, the pairs could short together or
to the cable sheath. I really can't see
Hello All:
I am hoping that some of you can help clarify the intent of requirement R9-20
in Telcordia GR-1089. Taken literally, the requirement says that there shall
be no damage to equipment, conductors, or components when the DC power supply
is shorted at the load. This could even be inter
17 matches
Mail list logo
