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Siemens 3RU5146-4DB0 — Overload Relays

Siemens 3RU5146-4DB0 SIRIUS Thermal Overload Relay, 18-25 A,

MPN3RU5146-4DB0

Siemens SIRIUS thermal overload relay, 3RU5146-4DB0, 3-pole, adjustable 18-25 A, CLASS 10 trip, screw terminals, 70 mm width, for S3 contactor mounting.

Siemens 3RU5146-4DB0 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RU5146-4DB0 — Identification
ParameterValue
Product brand nameSIRIUS
Product designationThermal overload relay
Combinable contactor sizesS3
3RU5146-4DB0 — Protection & Trip
ParameterValue
Overload current setting range18 ... 25 A
Trip classCLASS 10
Overload release typethermal
3RU5146-4DB0 — Electrical (main circuit)
ParameterValue
Rated operational current25 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)12 W
Per pole4 W
3RU5146-4DB0 — 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
3RU5146-4DB0 — 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)
3RU5146-4DB0 — Environmental
ParameterValue
Operating temperature-20 ... +70 °C
Transport temperature-55 ... +80 °C
Relative humidity, operating0 ... 100 %
Max. installation altitude2 000 m
3RU5146-4DB0 — Mechanical
ParameterValue
Width70 mm
Height120 mm
Depth140 mm

Product details

SIRIUS 3RU5146-4DB0 — Thermal Overload Relay, 18–25 A, CLASS 10

The Siemens 3RU5146-4DB0 is a SIRIUS thermal overload relay rated for a 25 A operational current, adjustable from 18 to 25 A via the current-dependent release. This is a current-production part (lifecycle stage: current).

Mounts directly onto a SIRIUS S3 contactor — no separate DIN-rail footprint needed, which saves a slot in a crowded panel. The 70 mm width matches the S3 contactor frame, so the assembly stays within the same envelope. Fastening method is contactor mounting, with the relay snapping onto the contactor's built-in rail. Side spacing requirement is 6 mm to grounded parts — plan for that gap when laying out adjacent components.

Main circuit terminals accept 2× (0.5 to 1.5 mm²) solid/stranded or 2× (0.75 to 2.5 mm²) — also 2× (10 to 1/0 AWG) or 1× (10 to 2/0 AWG). Auxiliary contacts take 2× (20 to 16 AWG) or 2× (18 to 14 AWG). Tightening torque for main contacts is 4 to 6 N·m. For short-circuit protection of the auxiliary switch, use a gL/gG fuse rated 6 A or a quick-acting 10 A fuse.

Frequently asked questions

What is the adjustable current range on the 3RU5146-4DB0?

The current-dependent overload release is adjustable from 18 to 25 A. The rated operational current is 25 A.

What trip class is the 3RU5146-4DB0?

Trip class is CLASS 10, meaning the relay will trip within 10 seconds at 7.2× the set current — suitable for standard motor protection.

What contactor does the 3RU5146-4DB0 mount to?

It mounts directly onto a SIRIUS S3 contactor. The fastening method is contactor mounting — no separate DIN-rail base required.

Where can I buy the 3RU5146-4DB0?

This part is sourced and quoted to order against an RFQ through independent distribution channels. Availability and current pricing are confirmed at quote time.

MPN
3RU5146-4DB0