Phase Motor Starter with Overload Protection
In order to fulfill the load requirements , the current exceeds its limit that means current draws more and the load requirement also goes higher which is called as overloading. The 3 Phase Motor Starter with Overload Protection is the protection or security performed when the excessive current or load is drawn by the motor which leads to heating also and effects the equipment.
It does the security of the equipment and also provide the safe starting current to the motor, so it provides the following protection to the motor:
- Overload Protection
- Over Current Protection
Overload Protection
It takes place in the condition when the current increases and the load increases as well beyond their limits ,thus the increasing current damages the wire and the motor windings as well which can cause fire hazards.
Overload relay is used for the protection in this case and it trips the power supply which protects the device from being damaged . In this case when the current overflows then it stops the flow of current as it exceeds its limit. Their are some types of overload relay which takes place are as follows:
- Thermal Overload Relay: It limits the amount of drawn current. As the heat generates by the overflow of current so a bimetallic strip is used to limit or break the flow of current so that it does not damages the device or equipment.
- Magnetic Overload Relay: This relay works on the principle of generation of magnetic field so when current flows then the magnetic field is produced around the coil which trips the terminals and breaks the current .
- Electronic Overload Relay: It is the solid relay which is not movable and it uses the sensors to monitor the flow of current and as the flow exceeds then it trips the terminals and breaks the flow of current.
Over Current Protection
The current flows in the large amount because of the ground fault or short circuit , thus the current which flows is called the faulty current and this condition is called overcurrent.
In this the current flows in the large amount which is not safe and hazardous to the operators and supply. In the cases of DOL Starter , fuses are used to control the condition of the overcurrent. The fuse is selected with proper ratings so that it does not get break with the heavy load or over current condition and thus it tolerated the overload as well as the starting current. The fuse or circuit breaker trips the contact terminals and breaks the flow of the current.
DOL Starter
For cases to avoid damage to the motor, various techniques are used to reduce the starting current with the use of a motor starter, these techniques vary on different factors and also protect the motor from overcurrent and overloading. DOL starter is one of the techniques used and in this article, we are going to discuss DOL starters and the starting of induction motors. We will cover what is starting induction motors and their functions, what are DOL starters, their application, terminologies, theory, construction, working, and the difference between DOL and star-delta starters.
Table of Content
- DOL Starter
- Important Terminologies
- Construction and Working
- 3 Phase Motor Starter with Overload Protection
- DOL Starter Wiring Diagram
- Advantages , Disadvantages and Applications