Lathem Dukane 24A715 - Manual (Page 72)

TYPE 24—Edwards Synchronous Wired Clocks, Type E1
During normal operation, 120Vac is applied between the run motor and common lines to
operate the clocks until the 58th minute. At HH:58:00 of each hour, the 120Vac is re-
placed by 120Vdc between the correction and common lines for a period of 200ms, with
the common line being positive. This pulse initiates hourly corrections for clocks that are
less than 60 minutes slow. At 5:58:09 AM and PM, an additional 120Vdc, 200ms pulse is
transmitted to correct clocks that are 60 or more minutes slow.
B-30 24A715/24A715M Master Clock Installation Manual
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
10 ASB MAX.
120Vac
2
2 = Diode bridge, 200V min PIV,
avg current = # clocks x 0.115A
1 = V250LA4 MOV or equal
1
AC RTN
BLK
RUN MOTOR
+
–
WHT
COMMON
1
RED
CORRECTION
Figure B-27
Edwards Synchronous Wired Clocks, Type E1