Title: Lab 4-7: Design and Build a Pre-Start Alarm, Then a Start Motor
Course: Electrical Motor Controls (Sandbox) > Section: Module 4: Control Relays and Timing Relays, 20 hr

Introduction

Background

In manufacturing plants, an operator may start a machine without a clear view of that machine.

When they do, they need to alert anyone that may be near that the machine is about to start. Normally this is done by setting off an audible alarm (a Pre-Start Alarm) for a few seconds before starting the machine. Workers are then trained to respond to the alarm. If the workers hear this alarm, they are to stay clear of the machinery because it's about to start.

Assignment

Your assignment for this lab is to design and build a circuit to accomplish this kind of alert. When the user presses the "Start" button, a buzzer goes off for three seconds. (Note: In Automation Studio, there is not a symbol for a buzzer, so you will need to choose a substitute output, like a Solenoid, in your schematic.) After that three seconds, a motor starter coil energizes.

You are expected to use a control relay and a timing relay in your design. Do not use a maintained switch to run the system. Use a "Start" button and a "Stop" button. The user should press and then release the "Start" button to start the system, and press and release the "Stop" button to stop the system.

Lab Instructions

1. Unplug the Motor Controls trainer.
2. Draw a schematic diagram, in Automation Studio or by hand, that represents a circuit that will operate as described above. Make sure your circuit works in simulation before moving on to the next step.
3. Build the circuit on the Motor Controls trainer.
4. Plug in and turn on the Motor Controls trainer.
5. Test the circuit.
6. An alert sound is made for three seconds when a user presses the "Start" button. After that three seconds, a motor starter coil energizes. This is done using a control relay and a timing relay.

Submission

To complete this lab, submit a 30-second video following the criteria found in the rubric. If you are working with another student, each of you must record and submit your own video.

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