SIEMENS SIRIUS 3RT20 Power Contactor, 37 kW, 72 A, 3-pole, 24 V AC Coil, 2 NO + 2 NC Auxiliary Contacts 3RT20381AD04

Power contactor from the SIRIUS 3RT20 series for switching three-phase motors up to 37 kW at 400 V. It handles rated operational currents of 72 A (AC-3) and 90 A (AC-1), making it suitable for demanding industrial applications.

Advantages

The contactor features a compact S3 size with screw terminals and supports both DIN rail and screw mounting. Its 24 V AC coil operates at 50/60 Hz, and the unit provides 2 NO and 2 NC auxiliary contacts for control and signaling.

Suitable for

• Motor starting and stopping in industrial control panels
• Switching resistive loads up to 90 A
• Applications requiring reliable auxiliary contact feedback

Key specifications

• Rated operational power: 37 kW (AC-3, 400 V)
• Rated operational current: 72 A (AC-3), 90 A (AC-1)
• Number of poles: 3
• Auxiliary contacts: 2 NO + 2 NC
• Control supply voltage: 24 V AC, 50/60 Hz
• Rated insulation voltage: 690 V
• Rated impulse withstand voltage: 6 kV
• Mechanical endurance: 10 million cycles
• Electrical endurance: 1.2 million cycles (AC-3)
• Mounting: DIN rail (35 mm) or screw
• Terminal type: Screw terminals
• Degree of protection (front): IP20
• Operating temperature: -25 to +60 °C

Recommendations

Use this contactor in motor starters for pumps, fans, and conveyors where reliable switching and auxiliary contacts are required.