Zohar,
If the power supply was approved by UL, get a copy of the UL descriptive report which should list the transformer temp. rating. You can also check the test report under para 5.1 (heating), the table in 1.5 (components), and Annex C (transformers).
You may also want to review the installation instructions to verify that you are providing the correct amount of cooling to the supply in your installation and operating at the ambient temperature as described in the agency test report.
Regards,
Ed
>From: Zohar Zosmanovich
>Reply-To: Zohar Zosmanovich
>To: "'Emc-Pstc (E-mail)"
>Subject: Transformer question
>Date: Mon, 18 Jun 2001 08:38:48 +0200
>
>
>Hello,
>
>I have a unit consist of metal enclosure and open frame AC/DC power supply,
>approved to UL/IEC 950.
>P.S includes PRI/SEC Transformer marked B/130 (Class B/130 deg.C).
>During Heating Test, transformer winding temperature exceeds class A limits
>(65 deg.C max. temperature rise). There is no mention about transformer
>class in UL report (class of insulation system) or in TUV certificate (but
>the power supply manufacture says it is class B).
>
>What class should I consider this transformer to be?
>
>Thanks
>
>
>
>Zohar Zosmanovich
>Compliance Engineer
>RadWin (The Wireless Alternative) Ltd.
>
>E-mail: zohar_zosmanov...@radwin.com
>RADWIN Ltd. 34 Habarzel St., Tel-Aviv 69710, Israel.
>Tel.: 972-3-7666735 Fax.: 972-3-7657535
>
>
>
>
>
>
>
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