The 125V NONC 4PST SEP CLOCK MTR/CIRCUIT These time switches provide a different 'ON/OFF' program each day of the week. They also provide for 4 pole single throw and 4 pole (2NO/2NC) switching. This series provides true 7-day load control with minimum ON and minimum OFF times of 3-1/2 hours. The 'BC' models with carryover provide a carryover of 16 hours minimum to maintain accurate load control even during power failure. When power resumes, the carryover automatically rewinds itself. Only 1 hour is required to rewind the carryover for each 2 hours of outage.