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Siemens 3RT1024-3BF40 — Contactors

Siemens 3RT1024-3BF40 SIRIUS Power Contactor, 110 VDC Coil,

MPN3RT1024-3BF40

Siemens SIRIUS power contactor, Size S0, 3RT1024-3BF40, 110 VDC coil, screw-type terminals, 5.5 kW AC-2 at 400 V, 7.5 kW at 500/690 V, IP20 front, snap-on 35 mm DIN rail.

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

3RT1024-3BF40 — Identification
ParameterValue
Contactor frame sizeS0
3RT1024-3BF40 — Ratings & Performance
ParameterValue
Rated operational current, AC-4 @ 400 V12.5 A
Rated value @ 400 V3 A
Rated value @ 500 V7.5 kW
Rated value @ 690 V7.5 kW
Rated value @ 230 V6 A
Rated value @ 24 V10 A
Rated value @ 60 V2 A
Rated value @ 110 V1 A
Rated value @ 220 V0.3 A
3RT1024-3BF40 — Control & Coil
ParameterValue
Control supply voltage typeDC
3RT1024-3BF40 — Contacts & Poles
ParameterValue
Main poles3
Main NO contacts3
Auxiliary contact reliability1 faulty switching per 100 million (17 V, 1 mA)
3RT1024-3BF40 — Protection & Coordination
ParameterValue
Short-circuit coordination type 1, fusefuse gL/gG: 63 A
Short-circuit coordination type 2, fusefuse gL/gG: 25 A
Aux. switch short-circuit protection, fusefuse gL/gG: 10 A
3RT1024-3BF40 — Connection & Mounting
ParameterValue
Main circuit connectionscrew-type terminals
Conductor cross-section, solid2x (0.25 ... 2.5 mm²)
Conductor cross-section, finely stranded w/ ferrule2x (0.25 ... 1.5 mm²)
Side-by-side mountingYes
3RT1024-3BF40 — Durability
ParameterValue
Durability (operating cycles, typ.)10 000 000
Durability with aux. switch block (cycles, typ.)10 000 000
3RT1024-3BF40 — Environmental
ParameterValue
Operating temperature range-25 ... +60 °C
3RT1024-3BF40 — Mechanical
ParameterValue
Width45 mm
Height85 mm
Depth100 mm

Product details

SIRIUS Size S0 power contactor, 110 VDC coil

The 110 VDC coil draws 5.4 W for both closing and holding, so the control transformer or DC supply needs to sustain that steady-state draw without sag — no inrush spike to worry about on DC, but the continuous 5.4 W means a 24 VA AC supply would be undersized if you're rectifying. Screw-type terminals on the main circuit accept up to 2x 10 mm² or 1x 8 AWG, and the auxiliary side handles 2x (0.25...2.5 mm²) solid.

Motor ratings and coordination

AC-4 at the same voltage is 12.5 A, covering plugging and inching duty for squirrel-cage motors. At 500 V and 690 V the contactor is rated for 7.5 kW, which is the same power at higher line voltages — useful where a 480 V or 690 V distribution is standard. Type 2 coordination requires a 25 A gL/gG fuse; Type 1 allows a 63 A fuse upstream. That selectivity window matters when you're coordinating with a motor protection breaker or downstream short-circuit device.

The 45 mm width (one standard modular unit) and 85 mm height fit a compact panel layout. Side-by-side mounting is permitted — no derating gap required between units in the same enclosure, though the IP20 front and IP00 terminal area mean you keep live parts behind a panel door or shrouding.

Frequently asked questions

Will 3RT1024-3BF40 drop into a panel specified around 3RT1023-1AL20 without rewiring?

Yes — same Size S0 frame, same screw-type terminal layout, same 45 mm width and DIN rail mounting. The difference is the coil voltage: 3RT1024-3BF40 uses 110 VDC, while the 3RT1023-1AL20 uses a different coil. Mechanical fit is identical; no rewiring of the power circuit needed.

MPN
3RT1024-3BF40