IE 411/561 Spring 2012
Problem Set 3

Learning Objectives: The main objective of this assignment is to start looking at using some engineering tools to understand some hazards better and improve safety. After successfully completing this assignment, you should be able to
Apply the principles of electric current flow to assess and prevent injuries from electricity, and
Use some standard guidelines to prevent cutting, crushing, or other injuries from equipment.

Before attempting Problem Set 3:
1. View Lectures 8 and 9
2. Read assignments associated with those lectures.
3. Do the Self-Checked problems associated with those lectures. If you want me to add a self-checked exercise, ask.

This, and other problem sets, are worth a maximum of 10 points. For IE 411 students, this is weighted to 7% of your grade. For IE 561 students, it is weighted to 6% of your grade.

Problem Set 3: For maximum credit, show all necessary work.

1. (4 pts) A machine’s input consists of two rollers that are 36 inches in diameter. The gap between the rollers is ¼ inch. If the guard opening is two inches, what is the closest it can be placed to the centerline of the rollers?

From the above chart, the Guard Location would be 1 inch.

2. (2 pts) A piece of equipment is powered by 308 volts AC. Calculate the minimum resistance needed by an insulating mat to assure that in the event of a short to the case of the cabinet, a worker will get no worse