DDC2 / 4-RS -24 Wiring Digital Display Wall Clock Guide Page 44
Appendix B - DDC2-RS-24 / DDC4-RS-24 Wiring
The DDC2-RS-24 and the DDC4-RS-24 allow for 24VAC supplied from the Master Clock or Power
Supply to power it for normal operation. These models can be used in installations where local 115V AC
power may not be available. When shipped, the DDC2-RS-24 and DDC4-RS-24 have an optional power
transformer that allows for 24VAC operation.
The 24VAC power from the Master Clock or Power Supply should be connected to the two black wires
leading from J1. (See figure 7 below for location of J1)
Correction wiring should be applied according to the secondary type selection as shown in Appendix A.

CAUTION: Applying any voltage higher than 24VAC to the input (two black leads

from J1) WILL cause damage to the DDC2-RS-24 and DDC4-RS-24 clocks.

Figure 7
JP2
Hours
Minutes
Up
Down
J4
J3
J1
O
P
E
N
1
2
3
4
5
6
7
8
DIP Switch
S1
9VDC Alkaline Battery
Cradle

- +

Lathem Time Corp.
DDC2\4 (E-PROM)
Jumper
Ground
Beeper
D-
D+
JP4
JP1
JP3
Fly Lead
Connector