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Siemens 3RT2028-2BF40 — Contactors

Siemens 3RT2028-2BF40 SIRIUS Power Contactor, 110 V Coil, S0

MPN3RT2028-2BF40
Active

Siemens SIRIUS, power contactor, Size S0, 3RT2028-2BF40, 110 V AC coil, spring-type terminals, 3-pole main contacts, auxiliary switch included.

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

3RT2028-2BF40 — Identification
ParameterValue
Contactor frame sizeS0
3RT2028-2BF40 — 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
3RT2028-2BF40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT2028-2BF40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT2028-2BF40 — 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)
3RT2028-2BF40 — 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
3RT2028-2BF40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT2028-2BF40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
Storage temperature range-55 ... +80 °C
Installation altitude, max.2 000 m
3RT2028-2BF40 — Mechanical
ParameterValue
Width45 mm
Height102 mm
Depth107 mm

Product details

It carries a 110 V AC coil and spring-type terminals on both power and auxiliary circuits — no screw torque to check, which saves time on a panel build or a quick swap-out on the route.

The main contacts are rated for AC-3 motor duty — that's the standard for squirrel-cage motors during starting and switching off under load. At 230 V, this contactor handles motor loads up to 5 hp, which covers a lot of common pump, fan, and conveyor motors on the plant floor. DC switching ratings are provided for several voltages: 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 3 A at 400 V. These matter if you're breaking DC loads like brake coils or DC bus circuits — the arc extinguishes differently than AC, so the contactor is specifically rated for it. The coil pickup is rated at 110 V with an operating range of 0.8 to 1.1 times rated value — so it pulls in reliably between 88 V and 121 V. Dropout and arcing times are in the 10–18 ms range, which is typical for this contactor class and fast enough for most control schemes. Switching frequency limits vary by duty: up to 1,000 operations per hour for AC-1 (resistive), 750/h for AC-2 and AC-3 (motor starting/stopping), and 250/h for AC-4 (plugging, inching, reversing). If you're running a high-cycle application like a rapid-indexing conveyor, stay within the AC-4 ceiling to avoid contact welding.

Wiring and Panel Integration

Strip length and ferrule sizing follow the usual spring-clamp practice — no special tools beyond a screwdriver to press the release. The 45 mm width and 102 mm height fit the standard S0 footprint; depth is 107 mm including the arc chamber. That's the minimum air gap to adjacent metalwork or other devices for safe operation at rated voltage. Keep those gaps in the panel layout, especially when mounting multiple contactors side-by-side.

Frequently asked questions

Where can I buy the 3RT2028-2BF40 and get a price?

The 3RT2028-2BF40 is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time.

What is the 3RT2028-2BF40 depth for panel layout?

The depth is 107 mm, with a width of 45 mm and height of 102 mm. Clearance requirements are 10 mm upwards, forwards, and downwards, and 6 mm at the sides.

What wire sizes does the 3RT2028-2BF40 accept?

The spring-type terminals accept solid or stranded wire from 1 to 10 mm², and two conductors per terminal from 0.5 to 2.5 mm².

What compliance documentation is available for the 3RT2028-2BF40?

As a current-production Siemens SIRIUS component, it carries standard industrial certifications including CE, UL, CSA, and IEC compliance per the SIRIUS series. RoHS and REACH declarations are available through Siemens documentation channels.

MPN
3RT2028-2BF40