How do you size a motor contactor?

How do you size a motor contactor?

As per above chart:

1. Type of Contactor = AC7b.
2. Size of Main Contactor = 100%X Full Load Current (Line).
3. Size of Main Contactor = 100%x6 = 6 Amp.
4. Making/Breaking Capacity of Contactor = Value above Chart x Full Load Current (Line).
5. Making/Breaking Capacity of Contactor = 8×6 = 52 Amp.

What size soft starter do I need?

In principle, soft starter size should be larger than that of the motor being driven. The rated capacity of the soft starter is usually chosen according to two nominal values, one is corresponding motor power, another is maximum allowable working current of soft starter.

What is the difference between a contactor and a motor starter?

The mechanical elements of starters and contactors are identical. The contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. A motor starter is simply a contactor PLUS an overload relay and is rated by motor HP or amperage.

What is the criteria to select the contactor?

The choice of contactor is dependant upon many parameters i.e. operating voltage, size of contacts, number of operations, ambient temperature, type of load supplied etc. Loads are categorised into various AC ratings, (AC1, AC2, AC3 etc.) and the higher the AC rating the more inductive the load becomes.

Which starter is used in HP motor?

Auto Transformer starter: An Autotransformer starter is used to decrease the applied voltage to a motor throughout its beginning. In this method, the starting current is limited by using a three-phase autotransformer to reduce the initial stator applied voltage.

When should you use a motor starter?

What Is the Purpose of a Motor Starter?

1. Electrical surges occur due to weather.
2. The initial load output of the motor in major equipment starting.
3. Sudden shifts in electrical use within your facility.
4. Undiagnosed electrical complications occur.

What are the three most common electrical ratings found on a motor starter?

Common Ratings There are three significant electrical ratings for motor starters: voltage, horsepower, and ampacity (current value). The voltage rating of a motor starter must be rated for at least the operating voltage of the motor that it controls. This rating is specified on the motor and starter nameplates.

How do I select a starter rated for my motor?

Choose a starter rated for current (Amps) higher than the FLA of your motor at the line power voltage you intend to use. 2. Overload Relay Range Choose the overload by selecting a current range that contains the FLA of the motor from step 1

How to select an IEC motor starter?

Selecting an IEC Motor Starter 1 Contactor Size & Line Power. Refer to your motor or equipment nameplate to verify the Full Load Amperage (FLA) at the line power voltage you intend to provide. 2 Overload Relay Range 3 AC Coil Control Power. Choose the control power used to close the contactor. 4 Control Power. 5 Enclosure Cover Buttons.

What are the components of a motor starter?

Assembled motor starters consist of a contactor, overload relay mounted in a NEMA 4X rated polycarbonate enclosure. You may refer to our detailed guide on selecting a contactor if you want to read up on contactors first.

How to choose a starter for a contactor?

Choose the control power used to close the contactor. Once you have done this it should narrow down the starters to those with components suitable for your motor, voltage and wiring. Then, select your starter configuration based on the following criteria according to your preference: 4. Control Power