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Siemens 3RT2028-1BG40 — Contactors

Siemens 3RT2028-1BG40 SIRIUS S0 Power Contactor, 24 VDC Coil

MPN3RT2028-1BG40
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Siemens SIRIUS S0 power contactor, 3RT2028-1BG40, 24 VDC coil, screw-type terminals, 45 mm width, 10 A rated current at 24 V, 107 mm depth.

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

3RT2028-1BG40 — Identification
ParameterValue
Contactor frame sizeS0
3RT2028-1BG40 — 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
3RT2028-1BG40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT2028-1BG40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT2028-1BG40 — 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)
3RT2028-1BG40 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Aux. / control circuit connectionscrew-type terminals
Conductor cross-section, solid1 ... 10 mm²
Conductor cross-section, solid or stranded2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 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
3RT2028-1BG40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2028-1BG40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2028-1BG40 — Mechanical
ParameterValue
Width45 mm
Height85 mm
Depth107 mm

Product details

The S0 frame size (45 mm wide, 85 mm tall, 107 mm deep) is the standard building block for motor loads up to roughly 5.5 kW at 400 V in AC-3 duty.

The main contactor is rated for 1 000 operations per hour in AC-1 (resistive) duty, 750/h in AC-2 and AC-3 (motor start/run), and 250/h in AC-4 (plugging/reversing). The AC-3e rating also sits at 750/h, matching the standard motor-switching tempo for conveyor, pump, and fan applications. The built-in auxiliary switch (1 N/O + 1 N/C, wired as 16-8 on the main contact block) carries 10 A at 24 VDC, 2 A at 48 VDC, 2 A at 60 VDC, 1 A at 110 VDC, 0.9 A at 125 VDC, 0.3 A at 220 VDC, and 3 A at 400 VAC. That DC curve matters if you are switching a PLC input or a DC brake coil — the 24 V rating is generous, but the drop-off above 60 V is steep.

Arcing time is 10 ms, and the DC dropout delay (coil off to contacts open) is 15-18 ms. That is fast enough for most safety circuits but worth noting if you are coordinating with a downstream contactor that has a longer dropout.

Frequently asked questions

Where can I buy 3RT2028-1BG40 and how do I get a price?

This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.

What is 3RT2028-1BG40's listed depth?

The depth is 107 mm.

What wire sizes does the 3RT2028-1BG40 accept?

The main circuit accepts solid or stranded conductors from 1 to 10 mm². The auxiliary terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²).

Will 3RT2028-1BG40 drop into a panel specified around 3RT2036-1AC20-ZX95 without rewiring?

Both are SIRIUS S0 frame contactors with the same 45 mm width, 85 mm height, and 107 mm depth, and both mount on 35 mm DIN rail. The 3RT2028-1BG40 uses a 24 VDC coil with screw terminals, while the 3RT2036-1AC20-ZX95 carries a different coil voltage and may include special markings (ZX95). The physical footprint is identical, so a direct swap is possible if the coil voltage matches the circuit.

MPN
3RT2028-1BG40