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Siemens 3RT2018-1BG42-0CC0 — Contactors

Siemens 3RT2018-1BG42-0CC0 Contactor, AC-3 7.5kW/400V, DC 12

MPN3RT2018-1BG42-0CC0

Siemens SIRIUS 3RT2018-1BG42-0CC0, AC-3 contactor, 7.5 kW / 400 V motor rating, DC 125 V coil, 1NC auxiliary, 3-pole, size S00 screw terminal.

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Independent China distributor & sourcing agent· Listing updated Sep 2026

Product details

Its AC-3 rating of 7.5 kW at 400 V defines the maximum three-phase induction motor it can switch under full load — a standard 10 hp (7.5 kW) motor on a 400 V line. The DC 125 V coil means this variant is intended for systems with a DC control bus at that voltage, not the more common 24 VDC or 110 VAC coils.

What the ratings mean in practice

At 7.5 kW / 400 V, the contactor's rated operational current in AC-3 is approximately 16 A. The S00 frame size occupies roughly 45 mm width on DIN rail, leaving room for an overload relay and busbars in a standard motor starter assembly.

Screw terminals on the S00 frame accept 1 x (0.75–4 mm²) or 2 x (0.75–2.5 mm²) solid/stranded copper. Torque to 1.2–1.5 Nm. The DC 125 V coil draws approximately 40 W inrush, 4 W hold — confirm the control transformer or DC supply can deliver the inrush without voltage sag. The contactor is IP20 rated for finger-safe installation inside an enclosure; no IP65 rating for external mounting.

Frequently asked questions

What is the DC coil voltage on this contactor?

The coil is rated for DC 125 V, so it requires a DC control supply at that voltage — not compatible with 24 VDC or 110 VAC coils without a converter.

What motor power can this contactor switch?

It is rated for AC-3 duty at 7.5 kW at 400 V, which covers a standard 10 hp three-phase induction motor on a 400 V line.

Does this contactor include auxiliary contacts?

Yes, it comes with one normally-closed (1NC) auxiliary contact built in.

What is the frame size and terminal type?

It is size S00 with screw terminals, designed for DIN-rail mounting and panel wiring.

MPN
3RT2018-1BG42-0CC0