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Siemens Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S2 - IEC Thermal Overload Relays
SiemensIEC Thermal Overload Relays

Siemens Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S2

The SIEMENS Overload Relay: Thermal Protection (SKU 499K20, MPN 3RU21364JB0) is an IEC thermal overload relay in Frame Size S2, compatible with SIRIUS contactors of the same frame size. It features a 1NO/1NC…

SKU 3G-OTH-42298

Brand
Siemens
Item
Overload Relay: Thermal Protection, 3 Poles, 1NO/1NC, Frame Size S2
Category
IEC Thermal Overload Relays
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Technical Specifications

Siemens
Manufacturer Part Number
3RU21364JB0
Type
1NO/1NC, Frame Size S2, 54 A – 65 A
Poles
3
Frame Size
S2
Compatible Contactors
Frame Size S2
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: Thermal Protection (SKU 499K20, MPN 3RU21364JB0) is an IEC thermal overload relay in Frame Size S2, compatible with SIRIUS contactors of the same frame size. It features a 1NO/1NC auxiliary contact form, a maximum voltage rating of 690V AC, and screw terminals. The relay includes integrated bimetallic elements, so no separate thermal units are required, and it does not offer phase loss sensitivity.

Frequently Asked Questions

What is the SIEMENS 3RU21364JB0 overload relay used for?

The SIEMENS 3RU21364JB0 overload relay provides thermal protection for three-phase motors in industrial applications. It is used with SIRIUS contactors of Frame Size S2 to prevent motor damage from overcurrent or phase imbalance, common in pumps, conveyors, and compressors.

What are the specifications of the SIEMENS 3RU21364JB0 overload relay?

The SIEMENS 3RU21364JB0 is an IEC thermal overload relay with Frame Size S2, rated for 54 A to 65 A. It has a 1NO/1NC auxiliary contact form, maximum voltage rating of 690V AC, and screw terminals. It includes integrated bimetallic elements and does not offer phase loss sensitivity.

Where to buy the SIEMENS 3RU21364JB0 overload relay worldwide?

You can source the SIEMENS 3RU21364JB0 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.

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

To select the correct SIEMENS overload relay, match the relay's current range (e.g., 54 A – 65 A for the 3RU21364JB0) to the motor's full-load current. Ensure the frame size (S2) is compatible with your SIRIUS contactor. Use screw terminals for wiring and verify the auxiliary contact configuration (1NO/1NC) meets your control circuit needs.

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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