How to select a contactor for a motor

how to select a contactor for a motor

How to Select a Contactor?

Nov 23,  · The pick-up voltage of a motor is considered while choosing a contactor. Rated Coil Voltage: The contactor coil voltage should be equal to the voltage of the circuit powering the coil while choosing a contactor. To correctly select a magnetic contactor, one should consider the utilization categories, the site supply voltage, and then the load’s electrical requirements. Check the Datasheet and Nameplate of both the Contactor and the load, in this case, a motor.

In previous blog posts, we talked about the differences between IEC vs. NEMA and discussed the basics of a motor starter. There are 5 main things to consider when selecting and sizing a contactor for your application click to jump to a category :.

The first item to consider is the load, which is measured in amperes. This load amperage is the amount of current required to power your device at the line voltage. I or A is the electric current in amperes, and V is the voltage.

Since P is based on your devices power requirements, it will remain constant, if how to select a contactor for a motor lower the voltage, the current must increase to balance what are the four aspects of accounting equation, and vice versa.

Generally speaking with motors and other industrial equipment, you want to look at the nameplate to confirm the input voltage and the Full Load Amperage FLA. Use it for guidance, but please always refer to the equipment nameplate for the specific information whenever possible as the FLA can vary greatly due to a variety of factors. Choose your motor horsepower, input voltage and single or 3 phase from the drop downs and the calculated full load amperage is displayed.

You should next how to select a contactor for a motor the control voltage to be used to power the contactor. This can be the same as the line voltage, however often a lower voltage is selected for the contactor for safety purposes.

Generally, coil voltages are V or below. This is important because these will in part, determine which contactor you use. Below is a chart of the utilization categories for IEC contactors. Choosing the right utilization code will extend the life of the contactor.

An incorrectly specified IEC contactor may work for a period of time, but the lifespan will be severely reduced. The most common mistake we see is incorrectly choosing AC-3 when AC-4 would be more appropriate, resulting in a shorter lifespan of the contactor. Springer Controls sizes our contactors for 10 million operations to ensure long life.

Another consideration is whether the motor operation requires reversing of the direction, in which case a reversing contactor would be required. Auxiliary contacts allow additional operations to take place when the contactor is energized. Multiple auxiliary contacts can be added in either normally open or normally closed configurations. A good example for using auxiliary contacts would be turning on a pilot light to indicate the motor is running. Adding additional contacts to a contactor is inexpensive and could save you time and money if you take the time to review the operation as a whole.

With answers to these 5 questions, you should how to select a contactor for a motor ready to fully specify a contactor to meet your requirements. There are 5 how to plant outdoor flower pots things to consider when selecting and sizing a contactor for your application click to jump to a category : Full load amperage Coil voltage IEC utilization category Reversing vs non-reversing Auxiliary contacts Full Load Amperage at Line Voltage The first item to consider is the load, which is measured in amperes.

AC-1 Non-inductive or slightly inductive loads, eg. Mixers, blenders AC-7b Motor-loads for household appliances: eg. Reversing vs Non-Reversing Contactors Another consideration is whether the motor operation requires reversing of the direction, in which case a reversing contactor would be required.

Auxiliary Contacts Auxiliary contacts allow additional operations to take place when the contactor is energized. This site uses cookies: Find out more. Okay, thanks. Switching of mixed resistive and inductive loads, including moderate overloads i.

Choosing the right Contactor for your Motor

Oct 23,  · Home» About Us» News» How to Select and Size an IEC Contactor. How to Select and Size an IEC Contactor. Posted October 23, by springercontrols. In previous blog posts, we talked about the differences between IEC vs. NEMA and discussed the basics of a motor lovesdatme.com we’re going to talk about selecting a contactor for your application requirements. How to choose a right contactor? The principles are as follows: Voltage class of alternating current contactor should be the same with load, and selected contactor should adapt to load. Calculating current of load should conform to capacity class of contactor. IEC contactors and starters can be mounted on a din rail (up to 65amps) or panel mounted. Definite Purpose (DP) - Definite purpose contactors and starters are intended to be used in the HVAC markets where low cost is the top priority and the duty cycle is low. These contactors are not designed to be turned on and off several times a minute.

Click to see full answer. In this way, how do I know the size of my contactor? Similarly, how is Mpcb motor rating calculated?

Based on the range: Calculate your current requirement. Consider 7. If you are doing any electrical design work, it should be in one step upgrade. What are the different types of contactors? There are different types of contacts in a contactor namely, contact springs, auxiliary contacts, and power contacts. Each type of contact has an individual role to play. Operating Principle of a Contactor: The current passing through the contactor excites the electromagnet.

How do I choose a contactor? Hints and Tips - What information is needed to select a contactor Coil Selection. AC or DC operation. Control circuit voltage e. Main Pole Selection. How does AC contactor work? AC Power Center The contactor is essentially a type of switch that receives a low voltage signal 24V from your furnace to power on. By creating a magnetic field, it pulls down a piece of metal that will connect both of the higher voltage sides.

How do I choose a motor starter? Overload Relay Range. AC Coil Control Power. Control Power. Enclosure Cover Buttons. What is a contactor used for? A contactor is a large relay, usually used to switch current to an electric motor or another high-power load. Large electric motors can be protected from overcurrent damage through the use of overload heaters and overload contacts.

How do you size an overload relay? Thermal Overload Relay Min. How do you calculate contactor coil current? How do I choose a motor wire size? Cable size is calculated in a motor by its current rating. Thickness of the cable is directly proportional to the ampere rating.. Just divide the kW by rated supply voltage you can determine the operating current by seeing that we can determine the thickness of the wire.. How do you determine overload size? Divide by the rated full load current from the motor nameplate.

This will be the load factor for the motor. What is full load amps? This is the amount of current amps the motor will draw from the electrical system when producing its rated output horsepower. How do you feed wild birds in the winter? How can a lipid be distinguished from a sugar? Co-authors 5.

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