It happens frequently: a manufacturer has a newly designed electrical product for the U.S. market and submits it to a testing lab for safety certification.  The manufacturer and the lab will both know the U.S. safety standard that covers the product submitted, and the lab proceeds to do its certification testing.  But an odd situation has been occuring with manufacturers of uninterruptible power systems (UPS).  Over the past number of years there has actually been a choice of standards that covers new designs of UPS – the current version of ANSI/UL 1778 (also a national standard in Canada) and an earlier version of ANSI/UL 1778.  To preserve the integrity of its UPS certification, UL had announced that it would certify new designs to just the most current version.  Through NEMA, manufacturers had asked for an extension to the earlier version of ANSI/UL 1778 so that designs could migrate in an orderly fashion to the recent version.  This request, unfortunately, was not successful.  With the sunset of the earlier version fast approaching, manufacturers with the assistance of UL and CSA staff have instead embarked on revising the next version of ANSI/UL 1778 (also to be a Canadian national standard).  This revision will include those safety requirements from the earlier version deemed less stringent than those in the recent version.  Presented to manufacturers as "optional," these less stringent requirements could be chosen for UPS intended strictly for the U.S. market.  The timetable to complete this ANSI/UL 1778 revision is aggressive, but the end result – a single U.S. safety standard for new UPS designs – should rectify the current odd situation for both manufacturers and test labs.

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