Lathem Dukane 24A715 - Manual (Page 71)

TYPE 23—Condor Digital Clocks (Model 2412)
For a list of Type 23 clocks, see the chart on the first page of this appendix.
Condor digital clocks initialize to 12:00 AM when power is first applied. During normal
operations, the clocks maintain time by counting the 60Hz AC line frequency. When the
line voltage drops to approximately two-thirds normal level, the clocks start rapidly ad-
vancing at a rate of two minutes per second. After applying power to the master clock
and entering system selection code 23, the master clock initializes to 12:00 AM.
Every twelve hours, at 11:59:56 AM and 11:59:56 PM, the master clock drops K6, re-
moving power from the clocks. At 00 seconds, K6 resumes operation, applying full
power to the clocks, which synchronizes them and corrects their displays to 12:00.
After time resets, manual clock advances, daylight saving changes, and power failures,
the master clock drops K6 at the following 56th second to disconnect power to the clocks.
At 00 seconds, K6 resumes operation, applying full power to the clocks and causing them
to display 12:00. At 02 seconds, K5 operates to furnish low voltage to the clocks, causing
them to fast advance at a rate of two minutes per second. When the new time is reached, K5
is dropped, furnishing full power to the clocks for normal operation.
If the digital clocks become unsynchronized with the master clock, they can be manually
reset using the [9]=SYNCH. CLOCKS function. See page 3-5.
24A715/24A715M Master Clock Installation Manual B-29
1 2 3 4 5 6 7 8
CLK1 OR CLK2
x
x
x
x
RELAY
K6 (K8)
RELAY
K5 (K7)
I I
MASTER CLOCK
FIELD CONNECTIONS
X = Normally open contact
I = Normally closed contact
24Vac
10 ASB MAX.
13–17Vac
AC RTN
CONDOR
2412 CLOCK & TRANSFORMER
10 ASB MAX.
Figure B-26
Condor Digital Clocks (Model 2412)