Skip to main content
Siemens 3RU2126-4DB0-ZX95 — Overload Relays

Siemens 3RU2126-4DB0-ZX95 SIRIUS thermal overload relay, CLA

MPN3RU2126-4DB0-ZX95
Active

Siemens SIRIUS 3RU2126-4DB0-ZX95 thermal overload relay, CLASS 10, S0 frame, 690 V rated, 11 kW at 400 V, auxiliary contact for message Tripped.

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

3RU2126-4DB0-ZX95 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationthermal overload relay
Frame size (overload relay)S0
Combinable contactor sizesS0
Reference code (IEC 81346-2)F
3RU2126-4DB0-ZX95 — Protection & Trip
ParameterValue
Overload current setting range20 ... 25 A
Trip classCLASS 10
Overload release typethermal
3RU2126-4DB0-ZX95 — Electrical (main circuit)
ParameterValue
Rated operational current25 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)8.1 W
Per pole2.7 W
3RU2126-4DB0-ZX95 — 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
3RU2126-4DB0-ZX95 — 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)
3RU2126-4DB0-ZX95 — 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
3RU2126-4DB0-ZX95 — Mechanical
ParameterValue
Width45 mm
Height85 mm
Depth85 mm

Product details

It mounts directly onto a contactor (fastening method: contactor mounting) and is rated for a main circuit voltage of 690 V, with a CLASS 10 trip characteristic — meaning it will trip within 10 seconds at 7.2× the set current, fast enough to protect standard induction motors during a locked-rotor start. The relay includes an integrated auxiliary switch that signals a tripped state (the note reads "for message "Tripped"") for remote annunciation or PLC input.

The S0 frame size keeps the footprint compact — 45 mm wide, 85 mm deep, 85 mm tall — so it fits standard DIN-rail enclosures without crowding adjacent devices. The auxiliary contact ratings span common control voltages: 2 A at 24 V DC, 3 A at 120 V AC, 2 A at 230 V AC, and 1 A at 400 V AC, which covers most PLC input and relay coil circuits in industrial panels.

The relay operates across -40 to +70 °C and includes temperature compensation from -40 to +60 °C, so it maintains accurate trip timing in outdoor cabinets or near heat sources. The substance prohibitance date of 10/01/2009 indicates RoHS compliance as of that date.

Wiring and installation

Main circuit terminals are screw-type, accepting 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire. Use a Pozidriv PZ 2 screwdriver with a 5 to 6 mm shaft diameter.

Frequently asked questions

What does the note 'for message Tripped' mean?

The integrated auxiliary switch outputs a signal when the relay has tripped, and this variant is configured to indicate that tripped state — useful for remote alarm or PLC input.

What compliance documentation is available?

The substance prohibitance date of 10/01/2009 indicates RoHS compliance. The relay carries the SIRIUS brand and is designed to IEC/EN 60947 standards for thermal overload relays.

Can this relay replace a 6ES7221-1BH32-0XB0 in a panel?

No — the 6ES7221-1BH32-0XB0 is a Siemens SIMATIC S7-1200 digital input module, a completely different product class. The 3RU2126-4DB0-ZX95 is a motor protection relay and cannot substitute for a PLC I/O module.

MPN
3RU2126-4DB0-ZX95