Electric Motor Control Basics - Book - Page 28
Industrial Control Basics: Part 2, Overload Relays
Summary
When a motor draws excess current, it is referred to as an overload, causing possible
overheating and damage to the windings of the motor. Overload relays protect the
motor, motor branch circuit, and motor branch circuit components from possible
damage. Being part of the motor starter assembly, overload relays protect the motor
by monitoring the current flowing in the circuit. Three types of overload relays are:
Bimetallic, Eutectic, and Solid State. Each type of overload has its own unique way
of sensing overcurrent. The best type of relay to use is based on the application and
discretion of the installation team.
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
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
28
