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Siemens 3RT2037-3KB40 — Contactors

Siemens 3RT2037-3KB40 SIRIUS S2 Coupling Contactor

MPN3RT2037-3KB40
Active

Siemens SIRIUS 3RT2037-3KB40, S2 coupling contactor, 24V coil, spring terminals, 55 mm wide.

$463.29Ref. price · indicative, final on quote
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

3RT2037-3KB40 — Identification
ParameterValue
Contactor frame sizeS2
3RT2037-3KB40 — Ratings & Performance
ParameterValue
Rated operational current, AC-12, max.10 A
Rated operational current, AC-4 @ 400 V55 A
Rated value @ 400 V3 A
Rated value @ 500 V2 A
Rated value @ 690 V1 A
Rated value @ 230 V10 hp
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT2037-3KB40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT2037-3KB40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT2037-3KB40 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusegG: 250 A (690 V, 100 kA), aM: 160 A (690 V, 100 kA), BS88: 200 A (415 V, 80 kA)
Short-circuit coordination type 2, fusegG: 125A (690V,100kA), aM: 63A (690V,100kA), BS88: 100A (415V,80kA)
Aux. switch short-circuit protection, fusegG: 10 A (500 V, 1 kA)
3RT2037-3KB40 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionspring-loaded terminals
Conductor cross-section, solid or stranded2x (0.5 ... 2.5 mm²)
Conductor cross-section, finely stranded w/ ferrule2x (0.5 ... 1.5 mm²)
Mounting methodscrew and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715
Side-by-side mountingYes
3RT2037-3KB40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2037-3KB40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2037-3KB40 — Mechanical
ParameterValue
Width55 mm
Height114 mm
Depth130 mm

Product details

This Siemens 3RT2037-3KB40 is a SIRIUS coupling contactor in the S2 frame. It's built for switching motors, rated to 700 operations per hour in AC-3 duty. The spring-type terminals make for quick wiring.

Out here in the grease, you want a contactor that can handle the cycles. The 3RT2037-3KB40 is rated for 700 ops/h in AC-3 motor duty, and 800 in AC-1 resistive – so it'll hold up in a regular motor start-stop. The coil pulls 2.6 A inrush, holds at 24 V on a 0.8 to 1.2 range. That gives you a bit of voltage tolerance if your control transformer is sagging.

Current production, so no hunting for last-time buys or worrying about obso. We can quote this against your BOM line – just send the RFQ.

Frequently asked questions

What are its key operating frequencies?

AC-3 motor duty: 700 ops/h, AC-1 resistive: 800 ops/h, AC-4 plugging/reversing: 200 ops/h.

What dimensions does it occupy on the DIN rail?

Width is 55 mm, depth 130 mm, height 114 mm.

MPN
3RT2037-3KB40