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Siemens 3RT2018-1UB42 — Contactors

Siemens 3RT2018-1UB42 SIRIUS Power Contactor, 24 VDC, Size S

MPN3RT2018-1UB42
Active

Siemens SIRIUS power contactor, 3RT2018-1UB42, Size S00, 24 VDC coil, screw-type terminals, 45 mm width, current lifecycle stage.

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

3RT2018-1UB42 — Identification
ParameterValue
Contactor frame sizeS00
3RT2018-1UB42 — 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
3RT2018-1UB42 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT2018-1UB42 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT2018-1UB42 — 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)
3RT2018-1UB42 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
Conductor cross-section, solid0.5 ... 4 mm²
Conductor cross-section, solid or stranded2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²), 2x 4 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 DIN rail according to DIN EN 60715
Side-by-side mountingYes
3RT2018-1UB42 — Durability
ParameterValue
Durability (operating cycles, typ.)30 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2018-1UB42 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2018-1UB42 — Mechanical
ParameterValue
Width45 mm
Height58 mm
Depth73 mm

Product details

The coil is rated 24 VDC. That's the nominal pull-in voltage; the dropout band sits at 7 to 13 ms, which matters if you're coordinating with a PLC output that needs to drop the contactor quickly on a safety stop. Main contact ratings are given per duty. At 230 V it handles 2 hp; at 400 V the current rating is 3 A. For DC switching, the auxiliary contacts break 10 A at 24 V, 2 A at 48 V, 2 A at 60 V, 1 A at 110 V, 0.9 A at 125 V, and 0.3 A at 220 V. So the DC curve drops fast above 60 V — if you're switching a 125 VDC solenoid bank, you're limited to 0.9 A per contact. Mechanical life is typical at 30,000,000 operations. The maximum switching frequency varies by duty: 1,000 1/h under AC-1 (resistive), 750 1/h under AC-2 and AC-3 (motor start/run), and 250 1/h under AC-4 (plugging/inching). AC-3e also maxes at 750 1/h. If your application cycles a conveyor motor at 500 starts per hour, the AC-3 rating has headroom.

The contactor measures 45 mm wide, 58 mm high, and 73 mm deep. For multiple conductors, it takes 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm². That covers most control-circuit wiring gauges you'd run in a panel.

Frequently asked questions

How do I get current pricing and availability for 3RT2018-1UB42?

Submit an RFQ through the storefront; availability and current pricing are confirmed at quote time through independent distribution channels.

What is 3RT2018-1UB42's listed depth?

The depth is 73 mm, with a width of 45 mm and height of 58 mm.

What wire sizes does 3RT2018-1UB42 accept?

Solid and stranded wire from 0.5 to 4 mm², with multiple-conductor combinations up to 2x 4 mm².

Will 3RT2018-1UB42 drop into a panel specified around 3RT2015-1BW42 without rewiring?

Both are Size S00 contactors on a 45 mm footprint with screw terminals, so they share the same DIN-rail slot and terminal spacing. The main difference is the coil voltage — the 3RT2015-1BW42 uses a 24 VAC coil, while this one is 24 VDC. Verify the control supply before swapping.

What compliance documentation does Siemens provide for 3RT2018-1UB42?

Standard Siemens SIRIUS documentation includes the declaration of conformity for the Low Voltage Directive and EMC Directive. RoHS and REACH compliance statements are available in the product's CE declaration. UL and CSA file numbers are listed on the nameplate and in the datasheet.

MPN
3RT2018-1UB42