:Re: Crepage/Clearance On Telecom Modem design
In a message dated 98-10-12, Mel Pederson writes:
If one considers the worst case (DC) voltages that could possibly exist on
TNV-3 lines and also SELV circuits, and considers the likelihood that these
are at opposite polarity, one would obtain a worst
Greetings,
The thing that has to be kept in mind though, is that the normal operating
voltage is not what is important. What is important is the ringing
voltage. The normal operating voltage in North America is only 48 V dc,
but when the phone rings, this ringing voltage is nominally 90 V ac.
Hello,
Its me again, with another two cents (Hey! maybe this one is worth a
nickel... :-).
Clause 2.2.7.4 talks about working voltages for determining Creepage
Distances with no apparent distinction between Primary and/or Secondary
circuits. The clause lists three bullets, with the third bullet
: kaan_greger...@mtn.3com.com
[SMTP:kaan_greger...@mtn.3com.com]
Sent: 13 October 1998 17:50
To: EMC-PSTC
Subject:Re: Crepage/Clearance On Telecom Modem design
Hello,
Its me again, with another two cents (Hey! maybe this one is worth a
nickel
Pedersen; emc-p...@majordomo.ieee.org; 'Diaco Davari'
Subject:Re: Crepage/Clearance On Telecom Modem design
Mel,
I notice you mentioned that European labs are using a working voltage of
150 Vdc which requires 1.6 mm creepage. I have assumed they were using 125
Vdc which requires only 1.5 mm
In a message dated 98-10-12, Mel Pederson writes:
If one considers the worst case (DC) voltages that could possibly exist on
TNV-3 lines and also SELV circuits, and considers the likelihood that these
are at opposite polarity, one would obtain a worst case 180VDC = -120VDC
(TNV-3) - 60VDC
: Crepage/Clearance On Telecom Modem design
This is my understanding of the situation Barry.
If one considers the worst case (DC) voltages that could possibly exist on
TNV-3 lines and also SELV circuits, and considers the likelihood that these are
at opposite polarity, one would obtain a worst case
: Crepage/Clearance On Telecom Modem design
Date: Friday, 9 October 1998 11:51
I believe that your experts are wrong...4.2 is a rather odd number to
come up with. The most common requirement here is SUPPLEMENTARY INSULATION
for a PRIMARY CIRCUIT at 250Vrms (as defined by EN 60950) between the
TIP
:Crepage/Clearance On Telecom Modem design
Hello Folks,
Does anyone know what the crepage distance shall be across the isolation
from the line side to modem side within the DAA of Modems?
Which document/standard refers to this specific spacing in detail ?
I have been told by local experts
Hello Diaco:
My reading of Clause 6 of IEC 950/EN 60950 is:
between TNV circuit and primary circuit:
double or reinforced insulation, including applicable
creepage distance and clearance, or
basic insulation and a grounded conductive barrier,
including
8:54 PM
To: dav...@pmc.philips.com
Cc: emc-p...@majordomo.ieee.org
Subject:Re: Crepage/Clearance On Telecom Modem design
Hello Diaco:
My reading of Clause 6 of IEC 950/EN 60950 is:
between TNV circuit and primary circuit
[SMTP:glenn.lesmeis...@compaq.com]
Sent: Friday, October 09, 1998 12:14 AM
To: 'Rich Nute'; dav...@pmc.philips.com
Cc: emc-p...@majordomo.ieee.org
Subject:RE: Crepage/Clearance On Telecom Modem design
In most cases, Norway, Sweden and Finland? require supplementary insulation
for a primary
modem is.
Best Regards,
Date sent: Thu, 08 Oct 1998 12:29:28 -0700
To: emc-p...@majordomo.ieee.org
From: Diaco Davari dav...@pmc.philips.com
Subject:Crepage/Clearance On Telecom Modem design
Send reply to: Diaco Davari
Hello Folks,
Does anyone know what the crepage distance shall be across the isolation
from the line side to modem side within the DAA of Modems?
Which document/standard refers to this specific spacing in detail ?
I have been told by local experts on EN60950 that I need 4.2 mm spacing
across
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