Phase 7: Contactors

This phase contains 5 sections and 38 checklist topics. Use the interactive phase page to track your own learning progress.

General topics

What is contactor?
Relay vs contactor
Why contactor is used
Coil
Core
Armature
Main contacts
Auxiliary contacts
And 3 more checklist topics

Terminals

A1/A2
L1/L2/L3
T1/T2/T3
13/14 NO
21/22 NC

Ratings

Coil voltage
Current rating
Voltage rating
Motor kW rating
AC-1
AC-3
Utilization category

Applications

Motor
Pump
Fan
Compressor
Heater
Lighting
Forward/reverse
Star-delta

Troubleshooting

Coil open
Wrong coil voltage
Contact welding
Contactor chatter
Burnt contacts
Weak coil
Mechanical jam

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slearnauto is an interactive industrial automation learning platform with progress tracking, flashcard quizzes, and interactive phase checklists. While JavaScript is required to track your progress and use the study tools, our complete 46-phase curriculum is available at: