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Siemens 3RT2018-4LB42-0LA0 — Contactors

Siemens SIRIUS 3RT2018-4LB42-0LA0 Contactor, 24 VDC Coil, Si

MPN3RT2018-4LB42-0LA0

Siemens SIRIUS contactor, 3RT2018-4LB42-0LA0, size S00, 24 VDC coil, extended operating range, screw and snap-on mounting.

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

3RT2018-4LB42-0LA0 — Identification
ParameterValue
Contactor frame sizeS00
3RT2018-4LB42-0LA0 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated operational current, AC-4 @ 400 V11.5 A
Rated value @ 400 V3 A
Rated value @ 500 V2 A
Rated value @ 690 V1 A
Rated value @ 230 V2 hp
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT2018-4LB42-0LA0 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT2018-4LB42-0LA0 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
3RT2018-4LB42-0LA0 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusegG: 50A (690V,100kA), aM: 25A (690V,100kA), BS88: 50A (415V,80kA)
Short-circuit coordination type 2, fusegG: 25A (690V,100kA), aM: 20A (690V,100kA), BS88: 25A (415V,80kA)
Aux. switch short-circuit protection, fusegG: 10 A (500 V, 1 kA)
3RT2018-4LB42-0LA0 — Connection & Mounting
ParameterValue
Main circuit connectionRing cable lug connection
Aux. / control circuit connectionring terminal lug connection
Conductor cross-section, solid2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 4 mm²
Mounting methodscrew and snap-on mounting onto 35 mm standard mounting rail according to DIN EN 60715
Side-by-side mountingYes
3RT2018-4LB42-0LA0 — Durability
ParameterValue
Durability (operating cycles, typ.)30 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2018-4LB42-0LA0 — Environmental
ParameterValue
Operating temperature range-40 ... +70 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2018-4LB42-0LA0 — Mechanical
ParameterValue
Width45 mm
Height61 mm
Depth117 mm

Product details

It mounts via screw or snap-on onto a 35 mm DIN rail per EN 60715, and the mounting position allows +/-180° rotation on a vertical surface plus +/-22.5° tilt forward or backward, giving flexibility in tight enclosures.

The 24 VDC coil holds at the rated value, and the extended operating range (0.7 to 1.25 x Uc) means the contactor picks up reliably even if the control supply sags to about 17 V or rises to 30 V — useful on lines with long DC runs or shared power supplies. The size S00 frame keeps the footprint compact at 45 mm wide, 61 mm tall, and 117 mm deep, so it fits standard 4-inch deep enclosures without crowding wireways.

Side-by-side mounting is allowed, with zero clearance on either side — no extra spacing needed between contactors in a row. The ring cable lug connection on the magnet coil means you need a ring terminal on the DC feed; plan for that in your wiring schedule. Auxiliary switch is built in, so you get one N.O./N.C. set without adding a separate block.

Frequently asked questions

What is the closest functional second-source if I cannot get this exact order code?

The closest functional peer is the 3RT2018-2AB02-ZX95, which shares the same size S00 frame and 24 VDC coil but lacks the extended operating range and the ring cable lug connection. It will drop into the same DIN-rail footprint, but verify the coil pick-up voltage tolerance and the auxiliary wiring before committing the BOM line.

Will it drop into a panel wired for a 3RT2018-2AB02-ZX95 without rewiring?

Yes, the footprint and DIN-rail mounting are identical, and both are size S00 with a 24 VDC coil. However, the 4LB42 variant uses a ring cable lug connection on the magnet coil instead of the screw terminal on the 2AB02, so you may need to change the coil wiring termination.

MPN
3RT2018-4LB42-0LA0