UL 1778 UPS Equipment requires that a fixed UPS has a disconnect switch for its output (or a cord and plug or receptacle on the output). Otherwise (according to UL 1778) the UPS instruction manual should require that you provide a disconnect device on the UPS output. However, these requirements are for fixed (permanently connected) UPSs. 15.4.1 of UL 1778 states "For a stationary unit, flexible cords and attachment plugs and receptacles shall be used for connection to the ac and dc input and output power circuits." There is then an exception for the ac output, which seems to be the provision of fixed wiring AND an opening or knockout for connection of conduit or a cable wiring system. A "stationary unit" is defined as "a cord and plug connected unit that is intended to be fastened in place or located in a dedicated place". Does your UPS have an on-off switch, and/or input/output receptacles ? John Crabb, Product Safety Engineer, NCR Financial Solutions Group Ltd, Dundee, Scotland. > -----Original Message----- > From: [email protected] [SMTP:[email protected]] > Sent: 25 October 1998 21:04 > To: Emc-Pstc > Subject: Disconnect Device for ITE or Lab Equipment Utilizing UPS > > Dear Members, > > The UL1950/EN 60950 and UL3101/EN601010 Standards require a > disconnect device for sevicing. The disconnect can be a switch > with a 3 mm contact gap or the appliance coupler or the plug on > the power supply cord. > > The equipment in question employs a UPS and employs an > appliance as the disconnect device. However, after detaching the > cord set, the UPS (a standalone Approved unit in itself) is live. > > Question: Do we have to introduce additional hardware to > disconnect the complete system from the supply for servicing? > > Looking forward to hearing from all of you. > > PETER S. MERGUERIAN > MANAGING DIRECTOR > PRODUCT TESTING DIVISION > I.T.L. (PRODUCT TESTING) LTD. > HACHAROSHET 26, P.O.B. 211 > OR YEHUDA 60251, ISRAEL > > TEL: 972-3-5339022 > FAX: 972-3-5339019 > E-MAIL: [email protected] > Visit our Website: http://www.itl.co.il >
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