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Siemens 3RU2126-1KB0-ZW96 — Overload Relays

Siemens 3RU2126-1KB0-ZW96 SIRIUS thermal overload relay, S0,

MPN3RU2126-1KB0-ZW96
Active

Siemens SIRIUS thermal overload relay, 3RU2126-1KB0-ZW96, S0 size, CLASS 10, 690 V rated, screw-type terminals, contactor mounting.

Source DocumentedChannel stated on listing & quote
Condition PhotosReal unit photos / video on request
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Worldwide DispatchDHL/FedEx — transit quoted per order
Independent China distributor & sourcing agent· Listing updated Sep 2026

Specifications

3RU2126-1KB0-ZW96 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationthermal overload relay
Frame size (overload relay)S0
Combinable contactor sizesS0
Reference code (IEC 81346-2)F
3RU2126-1KB0-ZW96 — Protection & Trip
ParameterValue
Overload current setting range9 ... 12.5 A
Trip classCLASS 10
Overload release typethermal
3RU2126-1KB0-ZW96 — Electrical (main circuit)
ParameterValue
Rated operational current12.5 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
3RU2126-1KB0-ZW96 — 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
3RU2126-1KB0-ZW96 — 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)
3RU2126-1KB0-ZW96 — 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
3RU2126-1KB0-ZW96 — Mechanical
ParameterValue
Width45 mm
Height85 mm
Depth85 mm

Product details

Rated at 690 V, with a maximum AC-3e switching voltage of 690 V, it covers 400 V, 480 V, 500 V, 600 V, and 690 V line supplies — the power ratings at those voltages are 5.5 kW, 12.5 A, 7.5 kW, 12.5 A, and 7.5 kW respectively.

The auxiliary contact ratings tell you what the integrated switch can handle: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V — these are the make/break capacities for the signal circuit feeding the PLC input or contactor coil. At 60 V the auxiliary contact is rated 0.3 A, at 110 V it is 0.22 A, at 125 V it is 0.22 A, and at 220 V it is 0.11 A — these lower DC ratings reflect the arc-extinction limits of the same switch when switching DC loads. The thermal overload release is temperature-compensated from -40 °C to +60 °C, so the trip curve stays accurate across most panel ambient conditions without manual adjustment. Power dissipation per pole is 2.2 W — useful for calculating the heat load inside a sealed enclosure when the relay is carrying full current.

Fastens directly to a contactor via the contactor mounting method — no DIN-rail adapter needed, though the S0 frame can also be snapped onto a DIN rail if the contactor itself is rail-mounted. Main circuit connections are screw-type terminals accepting 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire; the screwdriver tip required is Pozidriv PZ 2 with a shaft diameter of 5 to 6 mm. Dimensions are 85 mm deep, 45 mm wide, and 85 mm high — the S0 footprint is compact enough for high-density panels.

Substance prohibitance date is 10/01/2009, which aligns with the original RoHS compliance deadline — the relay meets RoHS requirements. MTTF with high demand rate is 2 280 years — a reliability figure that reflects the thermal bimetal design's long service life in cycling applications.

Frequently asked questions

What does the 'Note for message Tripped' mean?

The note indicates that this relay has an integrated auxiliary contact that changes state when the relay trips, providing a signal (e.g., to a PLC or indicator) that the overload has operated.

What are the key ratings for this thermal overload relay?

It is a CLASS 10 relay rated at 690 V, S0 frame size, with auxiliary contact ratings of 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. Power dissipation per pole is 2.2 W.

What compliance documentation does this relay carry?

The substance prohibitance date of 10/01/2009 confirms RoHS compliance. The relay is a Siemens SIRIUS product, which typically carries CE, UL, and CSA certifications, though specific marks are not listed in this evidence set.

MPN
3RU2126-1KB0-ZW96