Motor Starter Contactors

More Information about Motor Starter Contactors

IEC contactors are a specific type of motor starter contactors that adhere to the standards set by the International Electrotechnical Commission (IEC). They are commonly used in industrial applications and are designed to handle high currents and provide reliable motor protection.

Motor starter contactors are often used in conjunction with other protective devices such as circuit breakers, fuses, and thermal evaporators to provide comprehensive motor protection. They can be found in various types of equipment, from small motors to large industrial machines, and their current capacity varies depending on the specific application.

One of the main differences between contactors and relays is their current capacity. Contactors are designed to handle higher currents and are primarily used for switching power to motors, while relays are typically used for lower current control and switching applications.

Motor starter contactors play a crucial role in protecting the motor and the electrical circuit from damage due to overloads, short circuits, and other fault conditions. They are often referred to as starters or motor starters, and the terms are used interchangeably in many cases.

Motor starter contactors are devices used to control and protect electric motors. They are designed to operate reliably under different overloads and provide essential protection to the motor and associated equipment. They are commonly found in power distribution systems, industrial machinery, and various electrical applications.

FAQs

What are overload relays?

Overload relays are protective devices used in electrical systems to monitor the current flowing through a circuit and protect against excessive current or overload conditions. A starter employs overload relays to provide overload protection to electric motors.

Motor Control Basics

Motor control allows operational control of electrical motors in various environments. 

Motor control circuits provide a safe way to operate electrical motors. Back when motor control circuits were in their infancy, it would have been common to see a simple disconnect switch that would be used to turn on and off a motor. Depending on the size of the motor and how much voltage was required, operating this disconnect would have been dangerous, with a very high possibility of arcing or electrocution. Not to mention that when the disconnect was actuated, the large amount of inrush current would have damaged the motor over time.

In today's motor control circuits, there are a few common pieces of hardware. 

A circuit breaker is used to protect the motor and any hardware downstream. A contactor and an overload relay are connected together and function in tandem to allow for remote and safe operation of the motor. The contactor functions much like a relay, allowing for a smaller electrical circuit to remotely close the motor contacts, starting the motor. The overload relay is designed to protect the motor in the case of a prolonged overcurrent event. These two devices are wired in series, so that if the overload relay detects an overcurrent event, the contactor will open the motor contacts, shutting off power to the motor.

The other two most common types of motor control hardware are a soft starter and a Variable Frequency Drive (VFD). 

Both of these devices function in a similar way to the motor circuit with some added functions. The soft starter is designed to reduce large inrush current to the motor upon startup. This “soft starting” of the motor will prolong its life and allow for safer operation. The VFD performs the soft start functions, but also allows for speed control of the motor. This speed control is critical in many different environments and has made VFDs one of the most common and safe to use motor control circuits today.