Skip to main content
Log in
Siemens 3RU5146-4MB0 — Overload Relays

Siemens 3RU5146-4MB0 SIRIUS Overload Relay, CLASS 10

MPN3RU5146-4MB0

Siemens SIRIUS 3RU5146-4MB0 thermal overload relay, CLASS 10, 80-100 A adjustable current range, 1000 V rated, 3-pole, screw terminals, contactor mounting for S3 size.

Siemens 3RU5146-4MB0 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RU5146-4MB0 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationThermal overload relay
Combinable contactor sizesS3
3RU5146-4MB0 — Protection & Trip
ParameterValue
Overload current setting range80 ... 100 A
Trip classCLASS 10
Overload release typethermal
3RU5146-4MB0 — Electrical (main circuit)
ParameterValue
Rated operational current100 A
Poles (main circuit)3
Rated operating frequency50 ... 60 Hz
Rated insulation voltage (AC, pollution degree 3)1 000 V
Rated surge withstand voltage8 kV
Main current circuitscrew-type terminals
Power loss at rated current (hot)21 W
Per pole7 W
3RU5146-4MB0 — Auxiliary contacts
ParameterValue
Auxiliary switch short-circuit protection (required fuse)fuse gL/gG: 6 A, quick: 10 A
Switching current at 24 V1 A
Switching current at 110 V0.22 A
Switching current at 230 V2 A
3RU5146-4MB0 — Connection & Mounting
ParameterValue
Mounting / fastening methodContactor mounting
Mounting positionwith vertical mounting surface +/-135° rotatable, with vertical mounting surface +/- 45° tiltable to the front and back
Main-circuit connector arrangementTop and bottom
Auxiliary/control circuit connection typescrew-type terminals
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 (10 ... 1/0), 1x (10 ... 2/0)
Conductor range (AWG), auxiliary contacts2x (20 ... 16), 2x (18 ... 14)
3RU5146-4MB0 — Environmental
ParameterValue
Operating temperature-20 ... +70 °C
Transport temperature-55 ... +80 °C
Relative humidity, operating0 ... 100 %
Max. installation altitude2 000 m
3RU5146-4MB0 — Mechanical
ParameterValue
Width70 mm
Height120 mm
Depth140 mm

Product details

Trip class and current range for motor protection

The 3RU5146-4MB0: The adjustable current response range is 80 to 100 A, so you dial it in to match the motor nameplate full-load amps — no fixed-trip guessing.

It mounts directly onto the contactor — the fastening method is contactor mounting, and it's sized for Siemens S3 contactors. No separate DIN-rail footprint needed; it hangs off the contactor's own frame. The body is 140 mm deep, 70 mm wide, 120 mm tall — that's the envelope you need to clear in the panel, including the 6 mm side spacing to grounded parts.

Frequently asked questions

What contactor does 3RU5146-4MB0 mount to?

It mounts directly onto Siemens S3-size contactors via the contactor mounting fastening method. No separate DIN-rail bracket needed.

What is the adjustable current range for this overload relay?

The adjustable current response value is 80 to 100 A, set via the dial on the front. Match it to the motor FLA within that window.

MPN
3RU5146-4MB0