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 advancing 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, removing 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.

X = Normally open contact

I = Normally closed contact

RELAY

CONDOR

RELAYK5 (K7)2412 CLOCK & TRANSFORMER

K6 (K8)

 

 

x

 

x

I

 

I

 

CLK1 OR CLK2

 

 

 

 

 

x

 

 

 

 

 

 

 

 

 

MASTER CLOCK

 

 

 

 

 

 

 

 

FIELD CONNECTIONS

1

2

3

4

5

6

7

8

 

 

 

 

 

 

 

 

10 ASB MAX.

24Vac

10 ASB MAX.

13–17Vac

AC RTN

Figure B-26

Condor Digital Clocks (Model 2412)

24A715/24A715M Master Clock Installation Manual

B-29