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Siemens 3RT2028-1AC24 — Contactors

Siemens 3RT2028-1AC24 SIRIUS Power Contactor, Size S0, 24 VA

MPN3RT2028-1AC24
Active

Siemens SIRIUS power contactor, Size S0, 24 VAC coil, screw-type terminals, screw and snap-on 35 mm DIN rail mounting, 5 hp at 230 V, 3 A at 400 V.

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

3RT2028-1AC24 — Identification
ParameterValue
Contactor frame sizeS0
3RT2028-1AC24 — 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 V6 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT2028-1AC24 — Control & Coil
ParameterValue
Control supply voltage typeAC
Rated value @ 50 Hz0.25
Rated value @ 50 Hz24 V
3RT2028-1AC24 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT2028-1AC24 — 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)
3RT2028-1AC24 — 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
3RT2028-1AC24 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2028-1AC24 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2028-1AC24 — Mechanical
ParameterValue
Width45 mm
Height85 mm
Depth141 mm
3RT2028-1AC24 — Specifications
ParameterValue
At AC4 ... 16 ms

Product details

Siemens 3RT2028-1AC24 SIRIUS Power Contactor — Size S0, 24 VAC Coil

The AC-3 switching frequency maxes at 750 operations per hour, while AC-4 (plugging/reversing) is rated at 250 ops/h — the duty cycle drops when you're reversing or jogging against the load. That helps when you're shoehorning it into a crowded panel.

Wiring and Clearance

Coil and auxiliary wiring uses 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). No auxiliary switch is built in — if you need aux contacts, they're added separately. That's the minimum air gap for heat dissipation and arc containment — don't crowd it tighter. Physical footprint: 85 mm high, 45 mm wide, 141 mm deep. The S0 frame is one of the compact sizes in the SIRIUS line, so it fits standard panel layouts without eating up too much DIN rail.

Frequently asked questions

What wire sizes does the 3RT2028-1AC24 accept?

Main contacts accept solid or stranded wire from 1 to 10 mm². Coil and auxiliary terminals take 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). All terminals are screw-type.

Does the 3RT2028-1AC24 include an auxiliary switch?

No. The contactor ships without an auxiliary switch block. If you need aux contacts for feedback or interlocking, they must be added as a separate order.

MPN
3RT2028-1AC24