Skip to main content
Log in
Siemens 3RT7045-1AG20 — Contactors

Siemens 3RT7045-1AG20 SIRIUS 3RT Contactor, 3-pole, AC coil,

MPN3RT7045-1AG20

Siemens SIRIUS 3RT contactor, size S3, 3-pole, AC coil 110 V 50/60 Hz, screw terminals, 690 V AC-3 max, IP20 front.

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

3RT7045-1AG20 — Identification
ParameterValue
Contactor frame sizeS3
3RT7045-1AG20 — Ratings & Performance
ParameterValue
Rated value @ 400 V3 A
Rated value @ 690 V1 A
Rated value @ 230 V6 A
3RT7045-1AG20 — Control & Coil
ParameterValue
Control supply voltage typeAC
Rated value @ 50 Hz0.27
Rated value @ 50 Hz110 V
3RT7045-1AG20 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliabilityacceptability for PLC control (17 V, 5 mA)
3RT7045-1AG20 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusegL/gG NH 3NA: 200 A
Aux. switch short-circuit protection, fusefuse gL/gG: 10 A
3RT7045-1AG20 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
Conductor cross-section, solid or stranded2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 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
3RT7045-1AG20 — Environmental
ParameterValue
Operating temperature range-10 ... +55 °C
Storage temperature range-25 ... +70 °C
Installation altitude, max.2 000 m
3RT7045-1AG20 — Mechanical
ParameterValue
Width70 mm
Height148 mm
Depth139 mm

Product details

The 3RT7045-1AG20: Fastens with screws or snaps onto 35 mm or 75 mm standard mounting rail. Dimensions are 70 mm wide, 148 mm high, 139 mm deep — the width is the critical panel-space number.

Environmental and electrical margins

The front face carries IP20 (finger-safe), while the terminals are IP00 — meaning the wiring zone needs to be inside a panel or guarded.

Coil and control circuit details

The AC coil draws 0.27 W holding power at DC (the closing surge is 0.62 W). For a 110 V AC control supply, the inrush is brief, but verify your control transformer can handle the peak if multiple contactors pull in simultaneously. The auxiliary switch extension option is available if you need more than the built-in contacts. Screw terminals on both main and control circuits — standard for panel builders, no special tooling needed.

Frequently asked questions

What are the key dimensions for panel layout?

Width is 70 mm, height is 148 mm, depth is 139 mm. The 70 mm width is the dimension that determines how many units fit across a DIN rail or backplate.

What is the AC-3 voltage and current rating?

The AC-3 maximum operating voltage is 690 V. The exact AC-3 current rating depends on the specific motor current; the contactor is sized for the S3 frame class. The short-circuit coordination calls for a 200 A gL/gG NH fuse (type 1 coordination).

Can this contactor be mounted side-by-side with others?

Yes, side-by-side mounting is permitted without derating, as long as the ambient temperature stays within the -10 °C to +55 °C operating range.

What control voltage does the coil require?

The coil is AC only, rated for 110 V at both 50 Hz and 60 Hz. Holding power is 0.27 W DC; closing power is 0.62 W DC.

MPN
3RT7045-1AG20