Siemens 3RT2028-1BB44 SIRIUS Power Contactor 3P 38A 18.5kW 24VDC

The Siemens 3RT2028-1BB44 is a SIRIUS 3RT2 series power contactor rated at 38 A and 18.5 kW at 400 V AC-3e/AC-3, with a 24 V DC control coil and a built-in 2 NO + 2 NC auxiliary contact arrangement. Size S0, 3-pole construction with screw terminals and a removable auxiliary switch block.

Technical specifications:

• MLFB: 3RT2028-1BB44
• Manufacturer: Siemens
• Product line: SIRIUS
• Product type: Power contactor (3RT2)
• Size: S0
• Poles (main circuit): 3
• Rated current AC-3 at 400 V: 38 A
• Rated current AC-1 at 400 V / 40°C: 50 A
• Rated current AC-4 at 400 V: 22 A
• Rated operating power AC-3 at 400 V: 18.5 kW
• Rated operating power AC-3 at 230 V: 11 kW
• Max operating voltage (main circuit): 690 V
• Control supply voltage: 24 V DC
• Auxiliary contacts: 2 NO + 2 NC
• Terminal type: Screw terminal
• Insulation voltage (main and auxiliary circuit): 690 V
• Surge voltage resistance: 6 kV
• Closing power / holding power (coil): 5.9 W
• Power loss at rated current (hot state): 9.6 W
• Operating temperature: -25 ... +60°C
• Storage temperature: -55 ... +80°C
• Installation altitude: max. 2,000 m
• Mechanical service life: 10,000,000 operating cycles
• Net weight: 0.65 kg

Features and benefits:

• Removable auxiliary switch block allows flexible configuration of control contacts on site
• Wide operating temperature range (-25 to +60°C) suits demanding industrial environments
• 10 million cycle mechanical service life reduces maintenance intervals
• Compact S0 frame size with screw terminals simplifies panel installation and wiring
• DC-operated coil (24 V) with 0.8-1.1 operating range factor ensures reliable switching

Applications:

• Switching and controlling three-phase motors up to 18.5 kW in industrial drive systems
• Motor starter assemblies in control panels requiring AC-3e/AC-3 duty
• Automation systems with 24 V DC control circuits
• Reversing and star-delta starter combinations using the integrated auxiliary contacts

Compliant with EN 60947-4-1 and IEC 60947-1. Part of the Siemens SIRIUS 3RT2 range.

Also known as: Siemens 3RT2028-1BB44, SIRIUS 3RT2 power contactor 38A 24VDC.