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

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

The SIEMENS Overload Relay is an IEC electronic overload relay with 3 poles and a 1NO/1NC auxiliary contact form, housed in Frame Size S0. It features a maximum voltage rating of 690V AC, screw terminals, and is…

SKU 3G-OTH-44360

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

Siemens
Manufacturer Part Number
3RB31234NB0
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
Not Applicable to Electronic Type Overload Relays
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 an IEC electronic overload relay with 3 poles and a 1NO/1NC auxiliary contact form, housed in Frame Size S0. It features a maximum voltage rating of 690V AC, screw terminals, and is compatible with SIRIUS contactors of Frame Size S0. This electronic type does not require thermal units and has no phase loss sensitivity.

Frequently Asked Questions

What is the SIEMENS 3RB31234NB0 overload relay used for?

The SIEMENS 3RB31234NB0 is an IEC electronic overload relay used to protect motors from overcurrent conditions. It is designed for use with SIRIUS contactors in industrial automation and control panels, providing reliable protection without requiring thermal units.

What are the specifications of the SIEMENS 3RB31234NB0 overload relay?

The SIEMENS 3RB31234NB0 is a 3-pole electronic overload relay with a 1NO/1NC auxiliary contact form, Frame Size S0, and a maximum voltage rating of 690V AC. It features screw terminals, is compatible with SIRIUS contactors of Frame Size S0, and does not require thermal units.

Where to buy the SIEMENS 3RB31234NB0 overload relay worldwide?

You can source the SIEMENS 3RB31234NB0 overload relay through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to worldwide destinations, ensuring you receive genuine Siemens components for your application.

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

To select the correct SIEMENS overload relay, match the frame size (e.g., S0) to your contactor series (SIRIUS) and verify the motor's full-load current falls within the relay's adjustment range. For electronic types like the 3RB31234NB0, no thermal units are needed, simplifying installation.

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 electronic 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: Electronic Protection, 2 Poles, 1NO/1NC, Frame Size A, 0.25 A – 1 A (MPN 3UB88134AB2). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: Class 48 Overload Relays; Terminal Connection Type: Screw Terminals; Frame Size: A; Maximum Voltage Rating: 690V AC; Thermal Units Required: Not Applicable to Electronic Type Overload Relays; Compatible Contactors: Frame Size A.
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SIEMENS Overload Relay: Electronic Protection, 2 Poles, 1NO/1NC, Frame Size A, 0.25 A – 1 A (MPN 3UB88134AB2). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: Class 48 Overload Relays; Terminal Connection Type: Screw Terminals; Frame Size: A; Maximum Voltage Rating: 690V AC; Thermal Units Required: Not Applicable to Electronic Type Overload Relays; Compatible Contactors: Frame Size A.
SIEMENS Overload Relay: Electronic Protection, 3 Poles, 1NO/1NC, Frame Size S0, 6 A – 25 A (MPN 3RB31234QB0). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: SIRIUS; Terminal Connection Type: Screw Terminals; Frame Size: S0; Maximum Voltage Rating: 690V AC; Phase Loss Sensitivity: No; Thermal Units Required: Not Applicable to Electronic Type Overload Relays.
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SIEMENS Overload Relay: Electronic Protection, 3 Poles, 1NO/1NC, Frame Size S0, 6 A – 25 A (MPN 3RB31234QB0). Key specifications — Brand: SIEMENS; Auxiliary Contact Form: 1NO/1NC; Compatible Contactor Series: SIRIUS; Terminal Connection Type: Screw Terminals; Frame Size: S0; Maximum Voltage Rating: 690V AC; Phase Loss Sensitivity: No; Thermal Units Required: Not Applicable to Electronic Type Overload Relays.