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Siemens 3RT1045-1AF04 — Contactors

Siemens 3RT1045-1AF04 SIRIUS Power Contactor, 37 kW AC-2, 66

MPN3RT1045-1AF04

Siemens SIRIUS power contactor, size S3, 3RT1045-1AF04, AC-2 37 kW at 400 V, AC-4 66 A at 400 V, screw terminals, IP20 front, snap-on 35 mm rail.

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

3RT1045-1AF04 — Identification
ParameterValue
Contactor frame sizeS3
3RT1045-1AF04 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated operational current, AC-4 @ 400 V66 A
Rated value @ 400 V3 A
Rated value @ 500 V45 kW
Rated value @ 690 V21.1 kW
Rated value @ 230 V6 A
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT1045-1AF04 — Control & Coil
ParameterValue
Control supply voltage typeAC
Rated value @ 50 Hz0.8 ... 1.1
Rated value @ 50 Hz110 V
3RT1045-1AF04 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1045-1AF04 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusefuse gL/gG: 250 A
Short-circuit coordination type 2, fusefuse gL/gG: 160 A
Aux. switch short-circuit protection, fusefuse gL/gG: 10 A
3RT1045-1AF04 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
Conductor cross-section, solid2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), max. 2x (0.75 ... 4 mm²)
Conductor cross-section, solid or stranded2x (2.5 ... 16 mm²)
Conductor cross-section, finely stranded w/ ferrule2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)
Mounting methodscrew and snap-on mounting onto 35 mm and 75 mm standard mounting rail
Side-by-side mountingYes
3RT1045-1AF04 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1045-1AF04 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT1045-1AF04 — Mechanical
ParameterValue
Width70 mm
Height146 mm
Depth188 mm
3RT1045-1AF04 — Specifications
ParameterValue
At AC10 ... 25 ms

Product details

Integrator's note on the 3RT1045-1AF04

The Siemens 3RT1045-1AF04 is a SIRIUS power contactor in size S3, rated for AC-2 duty at 37 kW at 400 V and AC-4 switching at 66 A at 400 V. Coil holds at 24 VDC nominal, drops out below 18 V. AC1 rating carries the resistive load curve to 25 A. Auxiliary contacts share the same coil suppression; verify free-wheel diode polarity before energizing inductive loads downstream.

Switching performance and ratings

Rated for 50 Hz operation with a frequency tolerance of 0.8 to 1.1 times nominal. Arcing time is 10 to 15 ms; switching frequency at AC-3 is up to 1 000 operations per hour, at AC-4 up to 300 per hour. Mechanical endurance is typical 10 000 000 cycles. The auxiliary contacts handle 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, 6 A at 230 V, 3 A at 400 V — so they can drive small relays or PLC inputs directly.

Frequently asked questions

What compliance documentation does the 3RT1045-1AF04 have?

RoHS and REACH compliance with substance prohibitance dated 05/01/2012.

What are the key ratings for the 3RT1045-1AF04?

AC-2 rated 37 kW at 400 V, AC-4 rated 66 A at 400 V. Switching frequency up to 1 000 ops/h at AC-3, 300 ops/h at AC-4. Mechanical endurance 10 000 000 cycles.

What is the mounting method for the 3RT1045-1AF04?

Screw or snap-on mounting onto 35 mm or 75 mm standard DIN rail. Side-by-side mounting is allowed.

MPN
3RT1045-1AF04