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Siemens Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S00 - IEC Thermal Overload Relays
SiemensIEC Thermal Overload Relays

Siemens Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S00

The SIEMENS Overload Relay: Thermal Protection (MPN 3RU21161BB0) is an IEC thermal overload relay in Frame Size S00, designed for use with SIRIUS contactors of the same frame size. It features a 1NO/1NC auxiliary…

SKU 3G-OTH-40287

Brand
Siemens
Item
Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S00
Category
IEC Thermal Overload Relays
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Technical Specifications

Siemens
Manufacturer Part Number
3RU21161BB0
Type
1NO/1NC, Frame Size S00, 1.4 A – 2 A
Poles
3
Frame Size
S00
Compatible Contactors
Frame Size S00
Auxiliary Contact Form
1NO/1NC
Maximum Voltage Rating
690V AC
Phase Loss Sensitivity
No
Thermal Units Required
None (Relay Includes Integrated Bimetallic Elements)
Terminal Connection Type
Screw Terminals
Compatible Contactor Series
SIRIUS
View Full Spec Sheet

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Siemens Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The SIEMENS Overload Relay: Thermal Protection (MPN 3RU21161BB0) is an IEC thermal overload relay in Frame Size S00, designed for use with SIRIUS contactors of the same frame size. It features a 1NO/1NC auxiliary contact form, screw terminals, and a maximum voltage rating of 690V AC. The relay includes integrated bimetallic elements, eliminating the need for separate thermal units, and has a current range of 1.4 A to 2 A.

Frequently Asked Questions

What is the SIEMENS 3RU21161BB0 overload relay used for?

The SIEMENS 3RU21161BB0 is an IEC thermal overload relay used to protect motors from overcurrent and phase imbalance. It is designed for use with SIRIUS contactors in Frame Size S00, making it suitable for industrial automation, pump control, and conveyor systems where reliable thermal protection is required.

What are the specifications of the SIEMENS 3RU21161BB0 overload relay?

The SIEMENS 3RU21161BB0 is a 3-pole thermal overload relay with a current range of 1.4 A to 2 A, Frame Size S00, and a maximum voltage rating of 690V AC. It features 1NO/1NC auxiliary contacts, screw terminals, and integrated bimetallic elements, so no separate thermal units are needed. It is compatible with SIRIUS contactors of Frame Size S00.

Where to buy the SIEMENS 3RU21161BB0 overload relay worldwide?

You can source the SIEMENS 3RU21161BB0 overload relay worldwide through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to your location. Contact us for availability and lead time; we supply genuine SIEMENS components for industrial applications.

How to install the SIEMENS 3RU21161BB0 overload relay?

To install the SIEMENS 3RU21161BB0, first ensure the contactor is de-energized. Mount the relay directly onto a SIRIUS contactor of Frame Size S00 using the integrated clips. Connect the motor leads to the screw terminals, set the current dial to the motor's full-load amperage (1.4 A to 2 A), and verify the auxiliary contacts are wired correctly for your control circuit.

Used in

Common applications for Siemens
District cooling plants — LME73 + RWF55 for condenser-water modulation
Inflight catering and food-processing steam boilers — LMG22 with SQN90 air-fuel cross-damper
Hospital steam-plant redundancy — LME41 with QRA2 UV flame detection for dual-fuel boilers
Semiconductor fab process heat — LME23 and SKP55 gas valves on hot-oil heater skids
Container-terminal reefer-deck heating — LMG22 retrofit onto legacy burner racks

Siemens Products

3G Electric supplies Siemens iec thermal overload relays. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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