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Siemens 3RU1126-1HB0 — Overload Relays

Siemens 3RU1126-1HB0 SIRIUS Thermal Overload Relay, CLASS 10

MPN3RU1126-1HB0

Siemens SIRIUS thermal overload relay, 3RU1126-1HB0, CLASS 10, S0 frame, 3-pole, screw terminals, IP20 front, ATEX approved.

Source DocumentedChannel stated on listing & quote
Condition PhotosReal unit photos / video on request
WhatsApp AnswersFast human replies for machine-down parts
Worldwide DispatchDHL/FedEx — transit quoted per order
Independent China distributor & sourcing agent· Listing updated Sep 2026

Specifications

3RU1126-1HB0 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationthermal overload relay
Frame size (overload relay)S0
Combinable contactor sizesS0
3RU1126-1HB0 — Protection & Trip
ParameterValue
Overload current setting range5.5 ... 8 A
Trip classCLASS 10
3RU1126-1HB0 — Electrical (main circuit)
ParameterValue
Poles (main circuit)3
Rated insulation voltage (AC, pollution degree 3)690 V
Rated surge withstand voltage6 kV
Main current circuitscrew-type terminals
Power loss at rated current (hot)6.6 W
Per pole2.2 W
3RU1126-1HB0 — Auxiliary contacts
ParameterValue
Auxiliary contacts: NO1
Auxiliary contacts: NC1
Auxiliary contacts: CO (changeover)0
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
3RU1126-1HB0 — Connection & Mounting
ParameterValue
Mounting / fastening methodContactor mounting
Mounting positionwith vertical mounting surface +/-135° rotatable, with vertical mounting surface +/- 45° tiltable to the front and back
Auxiliary/control circuit connection typescrew-type terminals
Removable aux./control terminalNo
Conductor cross-section: solid2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)
Conductor cross-section: finely stranded with ferrule2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)
Conductor range (AWG), main contacts2x (16 ... 12), 2x (14 ... 8)
Conductor range (AWG), auxiliary contacts2x (20 ... 16), 2x (18 ... 14)
3RU1126-1HB0 — Environmental
ParameterValue
Operating temperature-20 ... +70 °C
Storage temperature-55 ... +80 °C
Transport temperature-55 ... +80 °C
Relative humidity, operating100 %
Max. installation altitude2 000 m
Shock resistance8g / 10 ms
3RU1126-1HB0 — Mechanical
ParameterValue
Width45 mm
Height97 mm
Depth96 mm
3RU1126-1HB0 — Specifications
ParameterValue
Type Of ProtectionDMT 98 ATEX G 001

Product details

Rated for a 3-pole main circuit with screw-type terminals on both the main and auxiliary/control circuits. Mounts directly to the S0 contactor. S0 frame size pairs with the S0 contactor family.

Trip Class 10 is the headline: at 7.2× the full-load current setting, the bimetal strip forces the contacts open within 10 seconds. That is fast enough to protect a motor winding from a locked-rotor event, but not so fast that it nuisance-trips on a normal high-inrush start. For motors with longer acceleration times (high-inertia loads like centrifuges or large fans), you would step to Class 20 or 30 — but for most standard squirrel-cage motors, Class 10 is the right call. The auxiliary contact ratings are given at multiple voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V. These are the switching capacities of the built-in N/C and N/O contacts that signal the trip condition back to the PLC or the contactor coil circuit. Power dissipation per pole is 2.2 W, so the total heat load from the three poles is 6.6 W when the relay is carrying rated current. That is moderate — plan for natural convection in the enclosure, but no forced cooling needed in a standard steel cabinet. Surge voltage resistance is rated at 6 kV, which aligns with IEC 60947-1 overvoltage category III for 400 V distribution panels. That means the relay's insulation can handle switching transients from contactor coils and nearby lightning-induced surges without flashover.

Fastening method is contactor mounting — clips directly onto the SIRIUS S0 contactor. No DIN rail required for the relay itself. Dimensions: 45 mm wide, 97 mm high, 96 mm deep. Clearances: 0 mm upwards, forwards, backwards, downwards; 6 mm at side. Wire capacity: solid conductors 2× (0.5…1.5 mm²) and 2× (0.75…2.5 mm²) for main and auxiliary circuits. AWG equivalents: 2× (16…12) and 2× (14…8) for main; 2× (20…16) and 2× (18…14) for auxiliary.

Operating temperature range: -20 to +70 °C. Storage and transport: -55 to +80 °C. Relative humidity during operation: 100 % — so condensation is tolerable as long as it is not immersed. Shock resistance: 8g for 10 ms, which covers most industrial vibration environments (pumps, compressors, conveyors). The relay carries ATEX protection type DMT 98 ATEX G 001, meaning it is approved for use in potentially explosive gas atmospheres (Zone 1 or Zone 2) when installed in an appropriate enclosure. That is a differentiator — not every thermal overload relay has an ATEX certificate, so if the line is in a hazardous area, this part keeps the approval chain intact.

Frequently asked questions

Where can I buy 3RU1126-1HB0 and get a price?

This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm quote.

MPN
3RU1126-1HB0