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Siemens 3RU1126-4BD0 — Overload Relays

Siemens 3RU1126-4BD0 SIRIUS Thermal Overload Relay, Class 10

MPN3RU1126-4BD0

Siemens SIRIUS thermal overload relay, 3RU1126-4BD0, S0 size, Class 10, contactor mounting, ATEX certified, 690 V AC-3 max, IP20 front.

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

3RU1126-4BD0 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationthermal overload relay
Frame size (overload relay)S0
Combinable contactor sizesS0
3RU1126-4BD0 — Protection & Trip
ParameterValue
Trip classCLASS 10
3RU1126-4BD0 — Electrical (main circuit)
ParameterValue
Poles (main circuit)3
Rated surge withstand voltage6 kV
Main current circuitscrew-type terminals
3RU1126-4BD0 — Auxiliary contacts
ParameterValue
Auxiliary contacts: NO1
Auxiliary contacts: NC1
Auxiliary switch short-circuit protection (required fuse)fuse gL/gG: 6 A, quick: 10 A
Switching current at 24 V1 A
Switching current at 110 V0.22 A
Switching current at 120 V3 A
Switching current at 125 V0.22 A
Switching current at 220 V0.11 A
Switching current at 230 V2 A
Switching current at 400 V1 A
3RU1126-4BD0 — Connection & Mounting
ParameterValue
Mounting positionwith vertical mounting surface +/-135° rotatable, with vertical mounting surface +/- 45° tiltable to the front and back
Conductor cross-section: solid2x (0.5 ... 2.5 mm²)
Conductor cross-section: finely stranded with ferrule2x (0.5 ... 1.5 mm²)
3RU1126-4BD0 — Environmental
ParameterValue
Operating temperature-20 ... +70 °C
Storage temperature-55 ... +80 °C
Transport temperature-55 ... +80 °C
Relative humidity, operating100 %
Shock resistance8g / 10 ms
3RU1126-4BD0 — Mechanical
ParameterValue
Width45 mm
Height97 mm
Depth96 mm
3RU1126-4BD0 — Specifications
ParameterValue
Type Of ProtectionDMT 98 ATEX G 001

Product details

It mounts directly onto a SIRIUS contactor (contactor mounting per), making it a matched pair for the S0 frame size.

ATEX and hazardous-area fit

This relay carries ATEX protection type DMT 98 ATEX G 001. That means it is certified for use in potentially explosive gas atmospheres — per IEC 60079, the enclosure and thermal elements are approved for Zone 1 and Zone 2 installations where a motor overload could otherwise become an ignition source. Confirm the Ex marking matches your area classification before committing the BOM line. The front face is IP20; the relay is not sealed for washdown, so it belongs inside a panel or an Ex-rated enclosure.

Main circuit terminals are screw-type. Solid conductors accepted: 2x (0.5 … 2.5 mm²); finely stranded with core-end processing: 2x (0.5 … 1.5 mm²). AWG equivalents for main contacts: 2x (16 … 12), 2x (14 … 8). Strip length and torque are per the terminal marking — no special tooling needed. The relay adds 45 mm width and 96 mm depth to the contactor assembly; account for the 6 mm side clearance when laying out the DIN rail.

Operating temperature range: -20 … +70 °C; storage/transport: -55 … +80 °C. The relay can be mounted on a vertical surface, rotatable ±135° and tiltable ±45° front/back. Shock rated at 8g / 10 ms. Maximum operating altitude 2 000 m. Relative humidity up to 100% during operation — condensation is permissible, but the IP20 front means the relay is not water-jet protected.

Power dissipation and auxiliary contact ratings

Total power dissipation in hot operating state: 8.1 W, or 2.7 W per pole. This matters for enclosure thermal rise — a panel with multiple S0 relays needs that heat accounted for. Auxiliary contact ratings (–): at 24 V it switches 1 A, at 230 V it switches 2 A, at 400 V it switches 1 A. No built-in auxiliary contacts; these are the ratings of the add-on auxiliary contact block if fitted.

Frequently asked questions

How do I get current pricing and availability for 3RU1126-4BD0?

Submit an RFQ through this listing. The part is sourced to order via independent distribution; availability and current pricing are confirmed at quote time.

What is 3RU1126-4BD0's listed depth?

The depth is 96 mm.

What solid conductor size does 3RU1126-4BD0 accept?

It accepts 2x (0.5 … 2.5 mm²) solid conductors.

What compliance documentation does Siemens provide for 3RU1126-4BD0?

The relay carries ATEX protection type DMT 98 ATEX G 001. The evidence does not list RoHS, REACH, UL, or IEC declarations for this specific order code.

MPN
3RU1126-4BD0