
Easy way to calculate motor torque, fuse, CB, OL relay and contactor
For both DOL and Star-Delta Starter input fields are:
- System Voltage (V)
- Phase (1ph/3ph)
- Type of Motor (single phase, 3-phase induction, synchronous, wound rotor etc.)
- Motor Size (HP or kW)
- Motor Code (A, B, C… -H)
- Motor Efficiency (%)
- Motor RPM
- System P.F
- Application of Motor (motor load in household application, hermetic refrigerant comperssor motor etc.)
According to above inputs, following starters components are calculated:
Motor Torque / Current
- Motor Rated Tourque (Full Load)
- Motor Rated Tourque (Full Load)
- Motor Starting Torque
- Lock Rotor Current IL (Min)
- Lock Rotor Current IL (Max)
- Motor Starting Current
- Motor Full Load Current (Line)
- Motor Full Load Current (Phase)
Fuse (As per NEC 430-52)
- Non-Time Delay Fuse (Max)
- Time Delay Fuse (Max)
Circuit Breaker (As per NEC 430-52)
- Instantaneous Trip Circuit Breaker (Max)
- Inverse Time Circuit Breaker (Max)
Over Load Relay Setting
- Relay Min (70% of FLC Phase)
- Relay Max (120% of FLC Phase) or
- Relay Setting (100% of FLC Line)
Contactor (for DOL starter)
- Type of Contactor
- Making / Breaking Capacity of Contactor:
- Main Contactor (100% of FLC Line):
Contactor (for Star-Delta Starter)
- Type of Contactor:
- Making / Breaking Capacity of Contactor:
- Main Contactor (58% of FLC Line):
- Delta Contactor (58% of FLC Line):
- Star Contactor (33% of FLC Line):
Transient Time Delay Setting (for Star-Delta Starter)
Software: | Calculate Size Of DOL and Star-Delta Starter Components |
Version: | 10.6.13 |
Developer: | Jignesh Parmar |
Size: | 274 KB |
Price: | Free |
Download: | Right here | Video Courses | Membership | Download Updates |

thank you, Great