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

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

The SIEMENS Overload Relay is a three-pole IEC thermal overload relay with frame size S0, featuring integrated bimetallic elements and auxiliary contact form 1NO/1NC. It has a maximum voltage rating of 690V AC and…

SKU 3G-OTH-39641

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

Siemens
Manufacturer Part Number
3RU21261FB0
Frame Size
S0
Compatible Contactors
Frame Size S0
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
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Siemens Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The SIEMENS Overload Relay is a three-pole IEC thermal overload relay with frame size S0, featuring integrated bimetallic elements and auxiliary contact form 1NO/1NC. It has a maximum voltage rating of 690V AC and uses screw terminals. This relay is compatible with SIRIUS contactors of frame size S0 and does not include phase loss sensitivity.

Supplied to the Philippines — compatible with 60 Hz installations. DHL Express delivery to Manila, Quezon City, Cebu, customs and duties handled door-to-door.

Frequently Asked Questions

What is the SIEMENS 3RU21261FB0 overload relay used for?

The SIEMENS 3RU21261FB0 is a three-pole IEC thermal overload relay used to protect motors from overcurrent and phase imbalance. It is designed for industrial applications requiring reliable thermal protection, compatible with SIRIUS contactors of frame size S0. The integrated bimetallic elements eliminate the need for separate thermal units.

What are the specifications of the SIEMENS 3RU21261FB0 overload relay?

The SIEMENS 3RU21261FB0 overload relay has frame size S0, auxiliary contact form 1NO/1NC, maximum voltage rating 690V AC, and screw terminals. It includes integrated bimetallic elements and does not offer phase loss sensitivity. It is compatible with SIRIUS contactors of frame size S0.

Where to buy the SIEMENS 3RU21261FB0 overload relay worldwide?

You can source the SIEMENS 3RU21261FB0 overload relay through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to worldwide destinations. Contact us for availability and lead time; we provide reliable sourcing for this Siemens thermal protection relay.

How to select the correct SIEMENS overload relay for a motor?

To select the correct SIEMENS overload relay, match the frame size (S0) and voltage rating (690V AC) to your contactor series (SIRIUS). Ensure the auxiliary contact form (1NO/1NC) meets your control circuit needs. The integrated bimetallic elements provide thermal protection without separate units. Consult the motor full-load current for proper setting.

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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SIEMENS Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S00, 0.18 A – 0.25 A (MPN 3RU21160CB0). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: SIRIUS; Terminal Connection Type: Screw Terminals; Frame Size: S00; Maximum Voltage Rating: 690V AC; Phase Loss Sensitivity: No; Thermal Units Required: None (Relay Includes Integrated Bimetallic Elements).
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SIEMENS Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S00, 0.18 A – 0.25 A (MPN 3RU21160CB0). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: SIRIUS; Terminal Connection Type: Screw Terminals; Frame Size: S00; Maximum Voltage Rating: 690V AC; Phase Loss Sensitivity: No; Thermal Units Required: None (Relay Includes Integrated Bimetallic Elements).
SIEMENS Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S00, 0.35 A – 0.5 A (MPN 3RU21160FB0). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: SIRIUS; Terminal Connection Type: Screw Terminals; Frame Size: S00; Maximum Voltage Rating: 690V AC; Phase Loss Sensitivity: No; Thermal Units Required: None (Relay Includes Integrated Bimetallic Elements).
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SIEMENS Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S00, 0.35 A – 0.5 A (MPN 3RU21160FB0). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: SIRIUS; Terminal Connection Type: Screw Terminals; Frame Size: S00; Maximum Voltage Rating: 690V AC; Phase Loss Sensitivity: No; Thermal Units Required: None (Relay Includes Integrated Bimetallic Elements).