How to Set a Traditional Clock System in a School

The traditional clock system in schools is a type known as "master and slave." A single master clock controlled a collection of slave clocks, or dials. Common from the early 1900s, these systems were useful in keeping all of a school’s clocks on the same time. The master clock sent out an electronic pulse to each of the slave clocks, and the hands on the slave clocks were moved the required amount. Setting a traditional clock system in a school involves setting the master clock to the correct time.

Things You'll Need

• Master clock
• Slave clock
• Utility knife
• Electrical tape

Instructions

1. Note the time on the master clock and the various slave clocks. Clocks in a traditional school system should be synchronized to the same time. At any given time; however, some of the slave clocks could be fast or slow.

2. Check the connections on slave clocks that show the incorrect time. Slave clocks are joined to the master clock by two or three wires. One wire is a ground that prevents dangerous surges of electricity. A second wire receives the electronic pulses from the master clock. On models that have three wires, the third wire serves to align the slave clock to the proper time. A signal to this wire prevents the clock hand from advancing past the 59th minute until it receives a fresh signal from the school system's master clock.

3. Reattach broken wires by splicing the two ends of the wire. Use a utility knife to cut away any wire installation that might be blocking access to the actual wires. Twist the free wires together until they are securely joined. Wrap the connection with electrical tape.

4. Check the wire connections on the master clock. Broken wires that protrude from the master clock also must be spliced together to permit the electrical signal to flow unimpeded.

5. Set the master clock by moving the clock hands to the correct time. Depending on the specific clock system, the slave clocks might not be synchronized until the master clock reaches the hour. At that point, all minute hands will advance to the correct hour.

Tips & Warnings

• Do not set the slave clocks manually. Manual setting could cause the clocks to be out of sync with the master clock.

• If all visible wire connections are intact, or repaired, a professional electrician should be consulted to check the wiring inside the walls. These wires connect the master clock to the slave clocks.

• If all wiring is intact and the clock system still is not working properly, there might be a problem with the master clock itself. A professional clock maker should be called in to evaluate the master clock.

References

• Which Clocks: Master/Slave Clocks
• Seasons Clock Systems: What is a Synchronized Clock System?
• National Instruments: Simplex/IBM 59th Minute 3 Wire Clock

Resources

• American Watch and Clock Institute (AWCI): Referral Directory for certified clock and watch repair