The thermal overload relay can make up a compact starting solution together with contactors.
Thermal overload relay.
If the motor pulls too much electricity for an extended period of time the relay may flip and cut the power to the motor to prevent damage.
These relays help to control the electrical current that goes to the motor to prevent it from overheating.
A thermal relay works depending upon the above mentioned property of metals.
A thermal overload relay is a small electromechanical device that protects motors from overheating.
The bimetallic strip gets heated up by the current directly or indirectly and when the current flow exceeds the set value it bends.
It is placed in the motor circuit in such a way that the current to the motor flows through its poles.
The basic working principle of thermal relay is that when a bimetallic strip is heated up by a heating coil carrying over current of the system it bends and makes normally open contacts.
It is connected either directly to motor lines or indirectly through current transformers.
Construction of thermal relay the construction of thermal relay is quite simple.
A thermal overload relay works in the principle of electro thermal properties in a bimetallic strip.
The function of a thermal overload relay used in motor starter circuits is to prevent the motor from drawing excessive current which is harmful to motor insulation.
Thermal overload relays are economic electromechanical protection devices for the main circuit.
Easy to create starters.
They offer reliable protection for motors in the event of overload or phase failure.