Reply to: RE>ISDN and T1 maximum voltage Dan,
The normal signaling pulse voltage is about 2.4 to 3.3 volts(part 68 68.308(2)(A)). The current is as determined by the impedance of the circuit which is nominally 120 ohms. (the test calls for a 100 ohm resistor) DC current is avoided on T1 to prevent transformer saturation and clock recovery. The max power less than 108 mW, based on V^2/R, where V = 3.3 (dc) and R=100 ohms. Of course the actual power produced is less than 108mW, more like 15mW total. I suspect that the scope of your question is was intended to be at larger voltages than this. Larger voltages are possible under stresses, such as magnetic induction from AC power lines, AC power cross accidents, or lightening. The results will depend on the severity of the stress, the primary protector at the demarcation point, and the protection devices in your interface. For guidelines on how to design your interface safely see UL 1950 3rd Edition. Cheers, hope this is what your are seeking. Michael Royer Senior Agency Compliance Engineer BABT Approvals Liaison Engineer N.E.T. (Network Equipment Technologies) 800 Saginaw Drive Redwood City, CA 94063 Voice: 415-780-4218 Fax: 415-780-5004 [email protected] -------------------------------------- List-Post: [email protected] Date: 9/18/96 9:58 AM To: Michael Royer From: [email protected] Subject: ISDN and T1 maximum voltage Hello fellow TREG'ers, One of my colleagues asked me the following questions and I was unable to provide an answer. I would welcome any help from some one who knows. The question is what is the maximum voltage and current I can expect to get out of a T1 or ISDN line. I know the power isn't very high normally, but how much can the max be? I couldn't find an upper limit. References to the correct standards would be nice. Thanks, Dan Teninty P.E. Senior Design Engineer Product Safety [email protected] FLUKE Corporation Everett, Washington (206) 356-6035 (206) 356-6490 fax ------------------ RFC822 Header Follows ------------------ Received: by Mac2.net.com with SMTP;18 Sep 1996 09:58:15 -0800 Received: from europe.std.com by unet.net.com (SMI-8.6/SMI-SVR4) id JAA01169; Wed, 18 Sep 1996 09:51:33 -0700 Received: by europe.std.com (8.7.5/BZS-8-1.0) id MAA21896; Wed, 18 Sep 1996 12:10:14 -0400 (EDT) X-Authentication-Warning: europe.std.com: daemon set sender to treg-approval using -f Received: from world.std.com by europe.std.com (8.7.5/BZS-8-1.0) id MAA21879; Wed, 18 Sep 1996 12:10:12 -0400 (EDT) Received: from fluke.com by world.std.com (5.65c/Spike-2.0) id AA02802; Wed, 18 Sep 1996 12:07:07 -0400 Received: by gateway.fluke.com id <36040>; Wed, 18 Sep 1996 09:06:14 -0700 List-Post: [email protected] Date: Wed, 18 Sep 1996 09:06:50 -0700 From: Dan Teninty <[email protected]> Subject: ISDN and T1 maximum voltage To: [email protected] Message-Id: <[email protected]> Priority: Normal Read-Receipt-To: Dan Teninty <[email protected]> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Sender: [email protected] Precedence: bulk Reply-To: [email protected]
