Electric Motor Control Basics - Book - Page 40
Industrial Control Basics: Part 3, Starters
Features of Motor Starters
Today, motor starters are used on a large scale due to their list of beneficial features.
The following are some features of these highly useful electrical devices:
• They facilitate the starting and stopping of the motor.
• The starters are rated by power (horsepower, kilowatt) and current (amperes).
• They provide the necessary overload protection for the motor.
• The electrical device facilitates remote on/off control feature.
• These devices allow you to make and break current rapidly (plugging and jogging).
Fundamental Functions of Motor Starters
Industrial Control
Basics:
Part 1, Contactors
Industrial Control
Basics: Part 2,
Overload Relays
Industrial Control
Basics: Part 3,
Starters
The Benefits of Type E/F
Motor Protection
Circuit Breakers
The following are the most fundamental functions that a starter has to perform:
1. Control: The control function is mainly carried out by the contactor component of
a starter. It is controlling the opening and closing of the power electrical circuit. The
switching is done by the main contacts (poles) of the contactor. An electromagnetic
coil is energized, which open or close the contacts. This electromagnetic coil has a
nominal control voltage, and can either be an AC or DC voltage.
2. Short-Circuit Protection: In industrial applications, normal load current can be
up to thousands of amperes. In the case of a short-circuit fault, the fault current
can go over 100,000 amperes. This can cause severe damage to the equipment. The
short-circuit protection disconnects the supply and prevents the potential damage
in a safe manner. Short circuit protection is provided by fuses or circuit breakers in a
Combination Motor Controller.
Basic Pump Control:
Three Phase DOL Starter
Control of an Electric Pump
Applying Motor Control
in a Wastewater
Application
NEMA vs IEC Motor
Controls
Understanding
IP Ratings
40
