SIEMENS 3RA2912-0 Relay Module

SIEMENS 3RA2912-0 Relay Module / Function Module

 

The SIEMENS 3RA2912-0 is a SIRIUS function module (star-delta / wye-delta starter base module) used in contactor-based motor starting systems, not an electronic relay module or PLC component.

Product Information

• Brand: Siemens
• Series: SIRIUS (3RA function modules)
• Model: 3RA2912-0
• Type: Function module / starter assembly accessory
• Function: Base module for star-delta (Y-Δ) motor starting circuits
• Compatible devices: Siemens 3RT2 contactors
• System role: Mechanical + electrical interconnection between contactors
• Application voltage: Low-voltage motor control systems

What it actually is

This is not a PLC module and not an electronic relay.

It is a mechanical/electrical connection and coordination module, meaning:

• It helps build a star-delta motor starter assembly
• It links multiple contactors together in a defined sequence
• It provides pre-designed wiring + mechanical interlocking concept

In simple terms:

It is a “starter kit base plate for assembling multiple contactors into a motor starting system.”

System Role (Simple)

Power supply
→ 3RT2 contactors (main / star / delta)
→ 3RA2912-0 module (this part)
→ motor starting sequence (reduce inrush current)

Key Features

• Designed for Siemens SIRIUS 3RT2 contactors
• Used in star-delta motor starting systems
• Reduces wiring complexity in MCC panels
• Ensures correct switching sequence
• Mechanical and electrical integration base
• Part of modular contactor assembly system

Typical Applications

• Motor control centers (MCC)
• Pumps and compressors
• Conveyor systems
• Industrial motor starting panels
• Heavy-duty 3-phase motors requiring reduced starting current

Important Notes

• Not a PLC ❌
• Not a relay module ❌
• Not a control board ❌
• Not a communication device ❌
• It is a motor starter function / assembly module ✔
• Works only with compatible Siemens 3RT2 contactors

Precautions

• Must be used in correct star-delta configuration
• Incorrect assembly may damage motor or contactors
• Requires proper phase sequencing
• Installation should be done in MCC panel environment
• Not a standalone electrical device