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 replaced 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.

X = Normally open contact

I = Normally closed contact

1= V250LA4 MOV or equal

2= Diode bridge, 200V min PIV, avg current = # clocks x 0.115A

RELAY

 

 

RELAY

 

 

 

 

 

 

K5 (K7)

 

 

 

 

K6 (K8)

 

 

 

 

 

 

 

 

 

x

 

x

I

 

I

 

 

 

 

 

 

 

 

x

 

 

 

CLK1 OR CLK2

 

 

 

 

 

 

 

MASTER CLOCK

 

1

2

3

4

5

6

7

8

FIELD CONNECTIONS

 

 

 

 

 

 

 

 

10 ASB MAX.

 

 

 

 

 

 

 

WHT

COMMON

 

 

 

 

 

 

 

 

120Vac

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BLK

RUN MOTOR

 

 

 

 

 

 

 

 

 

AC RTN

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

RED

 

 

 

 

 

 

 

 

 

CORRECTION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+

 

 

 

2 –

Figure B-27

Edwards Synchronous Wired Clocks, Type E1

B-30

24A715/24A715M Master Clock Installation Manual