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Siemens 3RT2028-2BB44 — Contactors

Siemens 3RT2028-2BB44 SIRIUS Power Contactor, Size S0, 24 VD

MPN3RT2028-2BB44
Active

Siemens SIRIUS 3RT2028-2BB44 power contactor, Size S0, 24 VDC coil, spring-type terminals, 45 mm width, 102 mm height, 154 mm depth.

$95.25Ref. 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

3RT2028-2BB44 — Identification
ParameterValue
Contactor frame sizeS0
3RT2028-2BB44 — 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
3RT2028-2BB44 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT2028-2BB44 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT2028-2BB44 — 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)
3RT2028-2BB44 — Connection & Mounting
ParameterValue
Main circuit connectionspring-loaded terminals
Aux. / control circuit connectionspring-loaded terminals
Conductor cross-section, solid1 ... 10 mm²
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
3RT2028-2BB44 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2028-2BB44 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2028-2BB44 — Mechanical
ParameterValue
Width45 mm
Height102 mm
Depth154 mm

Product details

The 45 mm width and 102 mm height leave room for adjacent devices in a crowded rail.

The main contacts are rated for 18 to 8 A, but the real selection driver is the duty-specific switching frequency. At AC-3 (squirrel-cage motor starting), the contactor handles up to 750 operations per hour; at AC-4 (plugging/reversing), that drops to 250 ops/h. For resistive loads (AC-1), it can cycle at 1,000 ops/h. These limits govern thermal rise in the enclosure — pushing past them accelerates contact wear. The 24 VDC coil draws 6 A at rated value, with a dropout time of 15 to 18 ms. Switching capacity on the coil side is specified across voltages: 2 A at 48 VDC, 1 A at 110 VDC, 0.3 A at 220 VDC, and 3 A at 400 VAC. The 1.1 full-scale factor and 0.8 initial value bracket the coil's operating range under varying supply conditions. Spring-type terminals accept solid or stranded wire from 1 to 10 mm², with dual-wire capability for 2x (0.5 to 2.5 mm²). This eliminates the need for ferrules on stranded conductors and speeds panel wiring.

Frequently asked questions

What are the key ratings for this contactor?

The 3RT2028-2BB44 is a Size S0 contactor with a 24 VDC coil, main contacts rated 18 to 8 A, AC-3 switching frequency of 750 ops/h, and spring-type terminals accepting 1 to 10 mm² wire.

What clearance is needed around this contactor in a panel?

Minimum clearances are 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the side.

What is the mechanical endurance of this contactor?

Typical mechanical endurance is 10 million operations.

MPN
3RT2028-2BB44