Wiring the Master Clock

This section provides instructions on wiring the power source, secondary clocks, and signaling devices to the master clock. It does not cover the connection of the optional modem, a computer, any RS-485 devices, and a power source for the optional remove schedule selector. Instructions for those devices are provided in Appendix C.

Stranded wire is recommended for use inside the power supply box, as it allows a firm connection to the quick connect terminals. There is also less chance of stranded wires interfering with the components on the relay board. If solid wire must be used, join the stranded wire to the solid wire in another box.

The master clock is supplied with quick connects. These should be attached to the wires as necessary so that the wiring can be connected to the terminal blocks as shown in Figure 1-4.

Figure 1-4

Plugging Quick Connects

into the Terminal Block

—WARNING—

Failure to properly connect the ground wire

can increase interference and cause

unsafe operating conditions.

Wiring Procedure

Figure 1-5on page 1-9shows terminal blocks P1 through P4, located on the PCB in the power supply backbox. Follow the steps below the figure to wire the clocks, power source, and signaling devices to the master clock.

Notes:

•Circuits CKT1 through CKT4 designate bell controls. Circuit pairs CKT5/CKT6 and CKT7/CKT8 can function as clock synchronization circuits or as bell controls.

•MOVs (Metal-Oxide Varistors) protect all relay contacts.

•Voltage-select jumpers connect to terminal block P4 for 120Vac operation. For clocks that must run at 220/240Vac, remove the 120V jumpers and install one jumper wire for the 240V selection. The system will automatically adjust for oper- ation at 50Hz or 60Hz at either voltage. Also see Terminal Block P4 on page C-2.

•Some clock setups may require external diodes or MOVs. See the wiring diagram for your type clock (see Appendix B).

1-8

24A715/24A715M Master Clock Installation Manual