Lathem 24A715 Time Clock User Manual


 
TYPE 08—Rauland 2410 Digital Clocks (24Vac and 120Vac)
Rauland 24Vac or 120Vac digital clocks initialize to 12:01 AM when first powered up.
During normal operation, the clocks maintain time by counting the 60Hz AC line
frequency. When the line voltage drops below 120Vac, the digital clocks start rapidly
advancing at two minutes per second. After applying power to the master clock and en
-
tering system selection code 08, the master initializes to 12:01 AM and applies normal
voltage to the digital clocks, causing them to set to 12:01 AM.
After initial power-up, any time change made at the master clock causes the SYS LED to
illuminate, indicating that the digital clocks are about to be corrected. At the 56th second,
the master clock removes power from the digital clocks, then at the 59th second applies
low voltage to the clocks, causing them to rapidly advance to the new time.
When the new time is reached, the master clock reapplies the normal voltage. If the digi
-
tal clocks become unsynchronized with the master, they can be manually reset using the
[9]=SYNCH. CLOCKS function. See page 3-5.
When a manual clock advance is initiated, the SYS LED illuminates, power is removed at
the 56th second, and a low voltage is applied at the 59th second, causing the clocks to ad-
vance to the current master time, at which point normal voltage is reapplied.
When a daylight saving mode, either forward or back, is initiated at 2:00 AM Sunday, the
master removes power from the clocks and applies low voltage, causing the clocks to rap-
idly advance to the new time, either 1:00 AM or 3:00 AM, at which point normal voltage
is reapplied.
Every 24 hours at 12:00:56 AM, the master clock removes power from the clocks, then
reapplies power at 12:00:59 AM, causing the clocks to set to 12:01:00 AM, thereby syn-
chronizing the clocks with the master clock.
See Figures B-10 and B-11 on the next page for the 120Vac and 24Vac wiring.
B-12
24A715/24A715M Master Clock Installation Manual