Product Description

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🛍️ Siemens 3RH2131-1BM408K SIRIUS Auxiliary Contactor Relay – 220V DC, 3NO+1NC

The Siemens 3RH2131-1BM408K is an authentic SIRIUS 3RH2 auxiliary contactor relay engineered for high-reliability signal switching, isolation, and safety-related control logic. Designed in a compact Size S00 frame, it features 3 Normally Open (3NO) + 1 Normally Closed (1NC) mechanically linked contacts and operates on a 220V DC control coil. This relay is ideal for power plants, substation control cabinets, and heavy industrial automation where 220V DC control voltage is standard.

Key Features & Technical Details

• 3NO + 1NC Mechanically Linked Contacts: Positively driven contact elements ensure that NO and NC contacts can never close simultaneously, fulfilling safety standards for interlocking and safety-related control circuits.

• 220V DC Control Coil: Optimized for standard 220V DC auxiliary power supplies, battery back-up systems, and high-voltage DC control networks.

• Compact Size S00 Frame: Offers high power density and saves space on DIN rails inside control cabinets and Motor Control Centers (MCCs).

• Vibration-Proof Screw Terminals: Equipped with durable screw connection technology for secure conductor clamping, fast installation, and minimal maintenance.

• High Mechanical Endurance: Manufactured to Siemens SIRIUS standards, offering long service life and exceptional switching reliability in demanding industrial environments.

• Dual Mounting Options: Supports fast snap-on mounting on standard 35mm DIN rail as well as direct panel screw mounting.

Ideal Applications

• Substation Control Panels & Power Distribution Systems

• Relay Logic Circuits & Auxiliary Control Isolation

• Safety Interlocking & Sequence Control Systems

• Motor Control Centers (MCC) & Battery-Backed DC Systems

• OEM Machinery, Machine Tools & Industrial Automation

❓ Frequently Asked Questions (FAQs)

Q1: What is the control coil voltage for the Siemens 3RH2131-1BM408K relay?

A: This model operates on a 220V DC control coil, making it suitable for 220V DC auxiliary supplies and power utility panels.

Q2: What is the contact arrangement for this auxiliary relay?

A: It is equipped with 3 Normally Open (3NO) + 1 Normally Closed (1NC) mechanically linked auxiliary contacts.

Q3: What safety feature do mechanically linked contacts provide?

A: Mechanically linked (positively driven) contacts ensure that the NO and NC contact sets cannot be closed at the same time, preventing false signals in critical safety interlocks and feedback circuits.

Q4: Can I expand the number of contacts on this S00 frame relay?

A: Yes, as part of the modular Siemens SIRIUS Size S00 ecosystem, you can easily attach top-mounted or side-mounted auxiliary contact blocks to add additional contacts.

🔗 Compatible Accessories & Cross-Selling Products

• Siemens 3RH2911 Series Auxiliary Contact Blocks: Snap-on front/side contact blocks to expand circuit logic with extra NO/NC contacts.

• Siemens 3RT201 Series Power Contactors (Size S00): Matching DC-operated power contactors for motor loads in the same panel setup.

• Siemens 3RT2916 Diode / Varistor Surge Suppressors: Plug-in surge suppression modules to protect 220V DC coil circuits from inductive voltage spikes.