Siemens 3RT20371KB443MA0 Contactor S2

Product Description

The SIEMENS 3RT20371KB443MA0 is a Size S2 three-phase power contactor designed for motor control and load switching in industrial electrical systems. It functions by opening and closing the main power circuit in response to a control signal, protecting motors and downstream equipment from unintended energization. Licensed electricians and industrial maintenance technicians install this type of contactor in motor control centers, panel boards, and machine control enclosures. The S2 frame size indicates a mid-range current capacity suitable for moderate-horsepower motor loads in commercial and light industrial applications.

This contactor is suited for three-phase motor starting and switching applications in commercial and industrial environments. Typical installation scenarios include motor control centers, HVAC equipment panels, pump control panels, and conveyor drive systems where reliable, repeatable switching of inductive loads is required. Its compact S2 footprint fits standard DIN-rail and panel mounting configurations common in industrial control cabinets.

Key Features

• Size S2 frame for mid-range motor control applications
• Three-phase power switching for motor and resistive load circuits
• Compact form factor compatible with standard industrial control enclosures
• Designed for DIN-rail or panel-mount installation
• Packaged as a single unit ready for direct installation

Compatibility

Designed as an OEM-style replacement or direct-install contactor for industrial motor control applications requiring an S2 size three-phase contactor. Consult the equipment nameplate and wiring diagram to confirm coil voltage and contact rating compatibility before installation.

Installation Notes

Installation should be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and any applicable local codes. De-energize and lock out the full panel before removing the existing contactor or installing this unit. Verify that the control coil voltage matches the available control circuit voltage before making connections. Do not exceed the rated current and voltage limits specified on the contactor nameplate.

Technical Specifications

• Frame Size: S2
• Dimensions (L x W x H): 7.402 inches x 5.157 inches x 3.150 inches
• Weight: 2.676 pounds
• Quantity per Pack: 1
• UPC: 80476617105

Standard Information

• Brand: SIEMENS
• Manufacturer Part Number: 3RT20371KB443MA0