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Siemens 3RU2126-1FB0 — Overload Relays

Siemens 3RU2126-1FB0 SIRIUS Overload Relay Class 10 S0

MPN3RU2126-1FB0
Active

Siemens SIRIUS 3RU2126-1FB0, size S0 thermal overload relay, Trip Class 10, with integrated auxiliary switch for trip signaling, 690 V rated.

$30.48Ref. price · indicative, final on quote
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

3RU2126-1FB0 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationthermal overload relay
Frame size (overload relay)S0
Combinable contactor sizesS0
Reference code (IEC 81346-2)F
3RU2126-1FB0 — Protection & Trip
ParameterValue
Overload current setting range3.5 ... 5 A
Trip classCLASS 10
Overload release typethermal
3RU2126-1FB0 — Electrical (main circuit)
ParameterValue
Rated operational current5 A
Poles (main circuit)3
Rated operating frequency50 ... 60 Hz
Rated insulation voltage (AC, pollution degree 3)690 V
Rated value (AC-3e), max.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
3RU2126-1FB0 — Auxiliary contacts
ParameterValue
Auxiliary contacts: NO1
Auxiliary contacts: NC1
Auxiliary contacts: CO (changeover)0
Auxiliary switch short-circuit protection (required fuse)fuse gG: 6 A, quick: 10 A
Switching current at 24 V2 A
Switching current at 60 V0.3 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
3RU2126-1FB0 — Connection & Mounting
ParameterValue
Mounting / fastening methodContactor mounting
Mounting positionany
Main-circuit connector arrangementTop and bottom
Auxiliary/control circuit connection typescrew-type terminals
Removable aux./control terminalNo
Conductor cross-section: solid or stranded2x (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)
3RU2126-1FB0 — Environmental
ParameterValue
Operating temperature-40 ... +70 °C
Storage temperature-55 ... +80 °C
Transport temperature-55 ... +80 °C
Relative humidity, operating10 ... 95 %
Max. installation altitude2 000 m
3RU2126-1FB0 — Mechanical
ParameterValue
Width45 mm
Height85 mm
Depth85 mm

Product details

The Siemens 3RU2126-1FB0 SIRIUS thermal overload relay, size S0, Trip Class 10, snaps directly onto a matching contactor frame. The integrated auxiliary switch (Noted as 'for message Tripped') provides a dry contact to signal the tripped state back to a PLC or HMI — no separate auxiliary block needed for basic fault indication.

Direct contactor mounting — no DIN-rail base required. Accepts a single M4 screw for each main circuit terminal; wire capacity: 2x (0.5–1.5 mm²) or 2x (0.75–2.5 mm²) solid or stranded. Screwdriver tip Pozidriv PZ2, shaft diameter 5–6 mm. Mounting position any. Temperature compensation active from -40°C to +60°C ambient, so trip current stays within curve even when the panel runs hot or cold.

RoHS compliance dated 10/01/2009 per the substance prohibitance entry.

Frequently asked questions

What does the Note 'for message Tripped' mean?

It indicates an integrated auxiliary switch that closes or opens when the overload relay trips, providing a dry-contact signal for a PLC, HMI, or alarm circuit.

What is the depth of this overload relay?

85 mm depth, with a 45 mm width and 85 mm height. These dimensions matter for gland-plate clearance and side-by-side contactor spacing.

MPN
3RU2126-1FB0