ELEC 252 - Industrial Electrical Motors and Controls

2 Credit: (1 lecture, 1 lab, 0 clinical) 2 Contact Hours: [ELEC 251 ]

This course is for those who have an understanding of electrical basics and want to learn more about industrial motors and their controls. Included is a study of limit switches, proximity switches, and use of contactors, reversing contactors, overload protection and variable frequency drives.
OFFERED: fall and spring semesters

Course Goals/ Objectives/ Competencies:
Goal 1: Demonstrate proper use of automatic input devices in relay ladder logic controls.

Connect and operate various input devices including: Limit, pressure, float switches, etc.
Demonstrate proper procedure for connecting H.O.A. (Hand-off-Automatic) control logic.
Connect and operate a sequence control logic circuit.
Design and Construct a sequence Control Circuit.

Goal 2: Demonstrate proper use timer control in relay ladder logic circuits.

Connect and operate on-delay/off-delay relay ladder logic circuits.
Design, connect, and operate a motor control circuit to perform time driven circuitry.
Design, connect, and operate a motor control circuit to perform an unloaded start of a motor.

Goal 3: Demonstrate proper use of basic electrical sensors used in relay ladder logic controls.

Compare and analyze the characteristics of capacitive vs inductive proximity switch performance.
Connect and operate a relay ladder logic control circuit using an inductive proximity switch.
Connect and operate a relay ladder logic control circuit using a capacitive proximity switch.
Connect and operate a motor control circuit with a photo electric sensor.
Design and construct a motor control circuit that will sense a product jam on a conveyor control system.

Goal 4: Explore the operation of variable frequency three phase motor drive (VFD).

Connect and operate a three-phase motor using the front keypad of a VFD.
Connect, program, and operate a VFD for three wire operation.
Connect, program, and operate a VFD for two wire operation.
Connect, program, and operate a VFD to jog a motor.

Goal 5: Explore the operation of variable frequency drive for speed and torque control.

Control the speed of a three-phase motor using the front panel controls of a VFD.
Program and operate a VFD to skip undesirable frequencies.
Program and operate a VFD to operate a motor above and below its data plate listed RPM.
Calculate volts per hertz ratio.
Program and operate a VFD to provide a motor with low speed boost.

Goal 6: Explore the operation of variable frequency drive for Acceleration Deceleration and Braking.

Program and operate a VFD to ramp a motor up to its rated speed.
Program and operate a VFD to ramp a motor down from its rated speed to a stop.
Program and operate a VFD to provide S curve acceleration to an induction motor.
Program and operate a VFD to provide DC injection braking.