Contents
How do I choose a 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.
How do you size a compressor contactor?
If the compressor is not listed in the table the contactor can always be sized for full voltage starting by selecting a contactor of the next amperage rating larger than the compressors Rated Load Amps (RLA) and then checking the LRA requirements against the rating of the chosen contactor.
What is contactor rating?
Ratings. Contactors are rated by designed load current per contact (pole), maximum fault withstand current, duty cycle, design life expectancy, voltage, and coil voltage.
Can you oversize a contactor?
A contactor is a glorified switch and the ratings are for its own function. You want to avoid under-sizing a contactor, but you can oversize.
How do you choose a contactor for a motor?
3 Steps to selecting the right contactor for your motor application
- Step 1: Gather the right information from your motor’s nameplate.
- Step 2: Find the right manufacturer’s datasheet and selection guideline for the load type.
- Step 3: Make the selection.
What does LRA mean on a contactor?
Locked Rotor Amps
The “FLA” (Full Load Amps) spec is the most important rating for most applications, and the 30-amp FLA of this contactor meets/exceeds your 25-amp minimum spec. This unit also has an LRA (Locked Rotor Amps) rating that exceeds your application specs…. So Yes! This particular contactor is likely suited to your needs.
How do I choose a motor contactor?
How is a contactor Energised?
Operating Principle of a Contactor:The current passing through the contactor excites the electromagnet. The excited electromagnet produces a magnetic field, causing the contactor core to move the armature. When current is removed, the coil is de-energized and opens the circuit.
What are the different types of contactors and overloads?
The product offering starts with Mini-Contactors in a compact 12 amp frame size, followed by Midi-Contactors in up to 100 amp frame sizes, and topped off with the Power-Contactors which offer up to 800 amp frame sizes. To complement the contactors, Thermal Overloads are offered for each frame size, available in several setting ranges.
How big are contactors, overloads and manual motor starters?
With CSA Elevator Ratings Power-Contactors and Overloads Up to 900 Amps or 600HP Manual Motor Starters 32, 63 and 100 Amp Frame Sizes CARLO GAVAZZI Automation Components CSOMMS-Bro.indd 1 10/3/08 11:32:31 AM Introduction CARLO GAVAZZI is proud to present our expanded range of contactors and
How many amps does a mini contactor have?
Contactors, Overloads and Manual Motor Starters Mini-Contactors and Overloads Up to 20 Amps or 7.5HP Midi-Contactors and Overloads Up to 140 Amps or 75HP With CSA Elevator Ratings Power-Contactors and Overloads Up to 900 Amps or 600HP
How many pole 40 amp contactors are there?
Only 3 left in stock – order soon. . Only 11 left in stock – order soon. . . Only 8 left in stock – order soon. . . . Only 12 left in stock – order soon. . Only 4 left in stock – order soon. . Only 3 left in stock – order soon.