(Solved): Connecting the Circuit 1. Assuming that relay CR is an 8-pin control relay and ...

Connecting the Circuit 1. Assuming that relay $\mathrm{CR}$ is an 8-pin control relay and that timer TR is a Dayton model 6 A855, place pin numbers beside the components of CR and TR in Figure 17-1. Circle the pin numbers to distinguish them from wire numbers. 2. Place wire numbers beside all circuit components in Figure 17-1. 3. Place corresponding wire numbers beside the components shown in Figure 17-3. Make certain to make the connection between $\mathrm{H}2$ and $\mathrm{H}3$ on the high-voltage side of the control transformers. 4. Connect the control section of the circuit shown in Figure 17-1. 5. Set the timing relay for a delay of five seconds. 6. After checking with the instructor, turn on the power and test the control section of the circuit for proper operation. 7. Turn off the power. 8. Connect the load section of the circuit. 9. Turn on the power and test the circuit for proper operation. (Note: Connect a voltmeter across the motor or equivalent motor load terminals and monitor the voltage. When the circuit is first energized, the voltage applied to the motor should be one-half the full line value. After a delay of five seconds, the voltage should increase to full value.) 10. Turn off the power and disconnect the circuit. Return the components to their proper place. Review Questions 1. How does the auto-transformer reduce the amount of starting current to a motor? 2. Is the auto-transformer used in this experiment connected as a wye, delta, or open delta? 3. What is the advantage, if any, of using an open delta connection as opposed to a closed delta or wye? 4. Assume that the line-to-line voltage in Figure $17?1$ is 480 volts. Also assume that when the start button is pressed, the motor starts with 240 volts applied to the motor. When the start button is released, however, the motor stops running. Which of the following could cause this problem? a. S1 coil is open. b. CR coil is open. c. TR coil is open. d. The stop push button is open. 5. Refer to the circuit shown in Figure 17-1. When the start button is pressed, nothing happens for a period of five seconds. After five seconds, the motor suddenly starts with full voltage connected to it. Which of the following could cause this problem? a. $CR$ coil is open. b. TR coil is open. c. $R$ coil is open. d. R normally closed auxiliary contact is open.