One possible answer re the hot air issue: Whatever the surface is (metal grill, plastic vent slots, etc.) that the hot air is exiting the equipment from, will have to comply with the external temperature limits already cited. If the air itself is so hot that there is a burn hazard, those external surfaces will likely fail the temperature limit.
Regards, Jim Eichner > Senior Regulatory Compliance Engineer Statpower Technologies Corporation [email protected] http://www.statpower.com Any opinions expressed are those of my invisible friend, who really exists. Honest. > -----Original Message----- > From: Israel Yeshurun [SMTP:[email protected]] > Sent: Thursday, October 07, 1999 3:43 AM > To: '[email protected]' > Subject: Hot Surface. Hot air. > > > > Dear Group Fellows > > I would like to raise the following two issues: > > 1) UL1950 / EN60950 Safety standards, Subclause 5.1 - Heating, > Table > 16 part 2, specify permissible temperature rise for external > surfaces of > equipment in Operator Access Area.. > For external surfaces, made of metal which may be touched, it > allows > temperature rise of 45 degrees Kelvin, assuming ambient temperature of > 25 > degrees Celsius it allows surface temperature of 70 degrees Celsius > = 158 > degrees Fahrenheit ! > Note (4) in this table applies to external surfaces that are not > likely > to be touched in normal use and measure less than 50 mm, in this case > it > allows a temperature rise of 75 degrees K, that under 25 degrees C > ambient > allows > 100 degrees C = 212 degrees F !! > > Now, 70 degrees C for external equipment surface that may be > touched > seems pretty high to me. 100 degrees C metal surface will, I believe, > cause > a burn to that part of the human body that touched it. > So maybe my interpretation is not true ?? and, can someone > point > another regulatory source for Hot surface permissible temperature ? > > 2) Regarding Hot air flowing out of equipment, in UL1950 / EN60950 > I > could not find a requirement or limit for the maximum permissible > temperature for it, Can someone point another regulatory source for > Hot air > permissible temperature ? > > Note: The equipment I relate to is ITE or Office, but > information from > Machinery standards or other sources is welcome ! > > > Many Thanks > Israel Yeshurun > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to [email protected] > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to [email protected], > [email protected], [email protected], or > [email protected] (the list administrators). > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
