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Siemens 3RU2126-1KJ0 — Overload Relays

Siemens 3RU2126-1KJ0 SIRIUS Thermal Overload Relay, CLASS 10

MPN3RU2126-1KJ0

Siemens SIRIUS thermal overload relay, 3RU2126-1KJ0, CLASS 10, size S0, 690 V rated, 45 x 85 x 85 mm.

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

3RU2126-1KJ0 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationthermal overload relay
Frame size (overload relay)S0
Combinable contactor sizesS0
Reference code (IEC 81346-2)F
3RU2126-1KJ0 — Protection & Trip
ParameterValue
Overload current setting range9 ... 12.5 A
Trip classCLASS 10
Overload release typethermal
3RU2126-1KJ0 — 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 circuitRing cable lug connection
Power loss at rated current (hot)6.6 W
Per pole2.2 W
3RU2126-1KJ0 — 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
3RU2126-1KJ0 — Connection & Mounting
ParameterValue
Mounting / fastening methodContactor mounting
Mounting positionany
Main-circuit connector arrangementTop and bottom
Auxiliary/control circuit connection typering terminal lug connection
Removable aux./control terminalNo
3RU2126-1KJ0 — 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
3RU2126-1KJ0 — Mechanical
ParameterValue
Width45 mm
Height85 mm
Depth85 mm

Product details

It's designed for motor protection in control panels, directly mounting onto a contactor.

Rated for main circuits up to 690 V and operating at 50/60 Hz. The auxiliary switch is integrated and carries the following contact ratings: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V, and 0.3 A at 60 V. These figures govern the control-circuit load it can switch — a PLC output or relay coil drawing, say, 0.5 A at 24 V is well within margin; a 2 A solenoid at 120 V is at the limit. The S0 frame size and 45 mm width mean it occupies a single 45 mm slot on the DIN rail when mounted on its matching contactor, leaving room alongside for the motor circuit breaker.

Compliance and environment

Temperature compensation is active from -40 to +60 °C, meaning the trip curve stays accurate across that span — important for outdoor or unheated enclosures. The MTTF at high demand rate is listed at 2,280 years, reflecting the relay's passive, fail-safe design. Substance prohibitance date is 10/01/2009, consistent with RoHS compliance. Ring cable lug connection is specified for the main current circuit.

Frequently asked questions

Where can I buy 3RU2126-1KJ0 and how do I get a price?

This part is sourced and quoted to order against an RFQ through independent distribution. Submit an RFQ for current availability and pricing.

What is 3RU2126-1KJ0's listed note (for message 'Tripped')?

The listed note is 'for message "Tripped"'. This indicates the relay's auxiliary contact is wired to signal a trip condition to a PLC or indicator.

What is 3RU2126-1KJ0's listed depth?

The depth is 85 mm. Combined with a width of 45 mm and height of 85 mm, it fits a standard 45 mm DIN-rail slot when mounted on its contactor.

Will 3RU2126-1KJ0 drop into a panel specified around 3RU2116-1FC1 without rewiring?

Both are SIRIUS S0-frame thermal overload relays with the same 45 mm width and contactor-mounting fastening. The 3RU2126-1KJ0 is a direct mechanical and electrical replacement for the 3RU2116-1FC1 in the same S0 footprint — no rewiring needed. Verify the current setting range on the nameplate matches your motor FLA.

What compliance documentation does Siemens provide for 3RU2126-1KJ0?

The substance prohibitance date of 10/01/2009 indicates RoHS compliance. The relay carries a 690 V rated value and is designed to IEC/EN 60947-4-1 standards typical for SIRIUS overload relays. For specific UL, CSA, or REACH declarations, request the manufacturer's compliance certificate with your RFQ.

MPN
3RU2126-1KJ0