Skip to main content
Siemens 3RU2126-1CC0 — Overload Relays

Siemens 3RU2126-1CC0 SIRIUS Thermal Overload Relay, Size S0,

MPN3RU2126-1CC0
Active

Siemens SIRIUS 3RU2126-1CC0 thermal overload relay, Size S0, Trip Class 10, 690 V rated voltage, 50/60 Hz, contactor mounting with spring-loaded terminals.

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

3RU2126-1CC0 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationthermal overload relay
Frame size (overload relay)S0
Combinable contactor sizesS0
Reference code (IEC 81346-2)F
3RU2126-1CC0 — Protection & Trip
ParameterValue
Overload current setting range1.8 ... 2.5 A
Trip classCLASS 10
Overload release typethermal
3RU2126-1CC0 — Electrical (main circuit)
ParameterValue
Rated operational current2.5 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 circuitspring-loaded terminals
Power loss at rated current (hot)5.7 W
Per pole1.9 W
3RU2126-1CC0 — 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
3RU2126-1CC0 — Connection & Mounting
ParameterValue
Mounting / fastening methodContactor mounting
Mounting positionany
Main-circuit connector arrangementTop and bottom
Auxiliary/control circuit connection typespring-loaded terminals
Removable aux./control terminalNo
Conductor cross-section: solid or stranded2x (0.5 ... 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 contacts1x (18 ... 8)
Conductor range (AWG), auxiliary contacts2x (20 ... 14)
3RU2126-1CC0 — 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
3RU2126-1CC0 — Mechanical
ParameterValue
Width45 mm
Height102 mm
Depth84 mm

Product details

It mounts directly to a contactor, making it a matched pair in a motor starter assembly.

Rated for 690 V at 50/60 Hz, this relay covers 400 V, 480 V, 500 V, and 690 V motor systems. The power ratings at each voltage tell you the maximum motor it can protect: 0.75 kW at 400 V, 1.1 kW at 500 V, and 1.5 kW at 690 V. The auxiliary contact is integrated and rated 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V — these are the switching capacities for the trip-signal circuit, not the motor current. The thermal release design means ambient temperature affects the trip curve; temperature compensation is active from -40 to +60 °C, so the relay holds its calibration across the panel's operating range. Power dissipation is 1.9 W per pole, which adds about 5.7 W total heat inside the enclosure. In a dense panel with multiple starters, that heat load matters for the thermal design — account for it in the ventilation or derating calculation.

Fastens directly to the contactor — no DIN rail required for the relay itself, though the contactor typically snaps onto one. The main circuit uses spring-loaded terminals accepting 2× (0.5 to 2.5 mm²) solid or stranded wire. A 3 mm diameter screwdriver shaft (3.0 × 0.5 mm tip) releases the spring clamp. Dimensions: 45 mm wide, 102 mm high, 84 mm deep — Size S0 footprint.

Frequently asked questions

What does the note 'for message Tripped' mean?

The note indicates that the auxiliary contact on this relay is wired to signal a 'Tripped' status — it closes or opens when the overload relay has operated, sending a fault message to the PLC or indicator.

What are the key electrical ratings for the 3RU2126-1CC0?

Rated voltage is 690 V at 50/60 Hz. The auxiliary contact is rated 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. Power dissipation is 1.9 W per pole. Trip Class is 10.

What compliance documentation is available?

The substance prohibition date of 10/01/2009 indicates RoHS compliance. The relay carries Siemens SIRIUS brand documentation including the standard CE declaration and UL/CSA file numbers typical for this series.

MPN
3RU2126-1CC0