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Siemens 3RT2027-4XB40-0LA2 — Contactors

Siemens 3RT2027-4XB40-0LA2 SIRIUS Contactor, 24 V DC

MPN3RT2027-4XB40-0LA2

Siemens SIRIUS 3RT2027-4XB40-0LA2 contactor, Size S0, 24 V DC coil, screw and snap-on DIN rail mounting, 45 mm width, 107 mm depth, ring cable lug coil connection.

Siemens 3RT2027-4XB40-0LA2 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

3RT2027-4XB40-0LA2 — Identification
ParameterValue
Contactor frame sizeS0
3RT2027-4XB40-0LA2 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated operational current, AC-4 @ 400 V22 A
Rated value @ 400 V3 A
Rated value @ 500 V2 A
Rated value @ 690 V1 A
Rated value @ 230 V5 hp
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT2027-4XB40-0LA2 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT2027-4XB40-0LA2 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
3RT2027-4XB40-0LA2 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusegG: 125A (690V,100kA), aM: 50A (690V,100kA), BS88: 125A (415V,80kA)
Short-circuit coordination type 2, fusegG: 50A (690V,100kA), aM: 25A (690V, 100kA), BS88: 50A (415V, 80kA)
Aux. switch short-circuit protection, fusegG: 10 A (500 V, 1 kA)
3RT2027-4XB40-0LA2 — Connection & Mounting
ParameterValue
Main circuit connectionRing cable lug connection
Aux. / control circuit connectionring terminal lug connection
Mounting methodscrew and snap-on mounting onto 35 mm standard mounting rail according to DIN EN 60715
Side-by-side mountingYes
3RT2027-4XB40-0LA2 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2027-4XB40-0LA2 — Environmental
ParameterValue
Operating temperature range-40 ... +70 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2027-4XB40-0LA2 — Mechanical
ParameterValue
Width45 mm
Height91 mm
Depth107 mm

Product details

SIRIUS Size S0 contactor with 24 V DC coil

The 3RT2027-4XB40-0LA2: It carries a 24 V DC coil with a ring cable lug connection — the DC coil holds in without hum, and the lug termination suits permanent wiring in a panel rather than a quick-disconnect tab.

Coil inrush and switching frequency by duty class

The DC coil draws a 3 A inrush peak at 24 V, settling to a 10 A holding current — the inrush is brief (30 to 50 ms) but the power supply must handle the peak without droop. Maximum switching frequency is 750 operations per hour for AC-1, AC-2, AC-3, and AC-3e duty classes, dropping to 250 ops/h for AC-4 (plugging/inching) — the AC-4 limit reflects the higher electrical wear from breaking motor starting current.

Operating environment and auxiliary contacts

An auxiliary switch is included as standard, so no separate add-on block is needed for basic status feedback or interlocking.

Frequently asked questions

What coil voltage does 3RT2027-4XB40-0LA2 use?

It uses a 24 V DC coil with a ring cable lug connection, drawing a 3 A inrush peak and 10 A holding current.

MPN
3RT2027-4XB40-0LA2