Motor Current & Overload Relay & Contractor Selection

⭐ Screw compressor Motor Current & Overload Relay & Contractor Selection

⚡ ampere‑based sizing · choose FLA input method
Typical screw compressor: 30–200 A
⚠️ Please fill all fields with valid positive numbers
📋 Standard IEC contactor ratings (AC‑3) are suggested. Overload range covers FLA.

How to Use This Calculator

Method 1: Enter motor FLA directly if known

Method 2: Calculate FLA from motor specifications (power, voltage, efficiency, power factor)

What This Calculator Provides

  • Motor Full Load Ampere (FLA)
  • Main contactor rating
  • Delta contactor rating
  • Star contactor rating
  • Overload relay range

Understanding the Results

All recommendations follow IEC AC-3 standard contactor ratings for motor control applications. The overload relay should be set to the motor’s FLA value within the specified range.