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Siemens 5SY7104-8 — 1-Pole MCB (DIN Rail)

Siemens 5SY7104-8 SENTRON MCB, 4A D-Curve, 1-Pole, 15kA

MPN5SY7104-8
Active

Siemens SENTRON 5SY7104-8 miniature circuit breaker, 1-pole, 4 A rated, D tripping characteristic, 15 kA breaking capacity per EN 60898, 40 kA per IEC 60947-2.

$19.05Ref. 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

5SY7104-8 — Identification
ParameterValue
Product designationMiniature circuit breaker
Brand nameSENTRON
Number of poles1
Pole design1P
Application suitabilityMechanical engineering / industry
5SY7104-8 — Electrical & Protection
ParameterValue
Tripping characteristic classD
Overvoltage categoryIII
5SY7104-8 — Mounting & Connection
ParameterValue
Mounting positionany
Fastening methodQuick assembly system
Combined terminal, topYes
Combined terminal, bottomYes
Width18 mm
Height90 mm
Depth76 mm
Installation depth70 mm
Modular width units1
Torque, min.-40 °C
Torque, max.75 °C
SealableYes
5SY7104-8 — Environmental
ParameterValue
IP protection classIP20, with connected conductors
Pollution degree3
Halogen-freeYes
Silicone-freeYes

Product details

Temperature derating and real-world current

The 4 A rating holds at 35 °C ambient. At 40 °C it derates to 3.76 A, at 50 °C to 3.5 A, and at 60 °C to 3.22 A. That derating curve matters when sizing for a motor branch that pulls 3.8 A at full load; you'd need to step up one frame size or improve ventilation.

The 5SY7104-8 is dual-rated: it meets IEC/EN 60898-1 for residential/commercial MCB duty and IEC/EN 60947-2 plus UL 1077 for industrial supplemental protection. That dual listing means it can serve in a UL 508A panel as a branch-circuit protective device (supplemental) or in a European-spec distribution board.

Frequently asked questions

What is the breaking capacity of 5SY7104-8?

15 kA per EN 60898 and 40 kA per IEC 60947-2. At DC per IEC 60947-2 it is rated 15 kA.

What is the D-curve on this MCB for?

D-curve trips between 10x and 20x rated current, designed for loads with high inrush like motors, transformers, and welding equipment.

Where can I buy 5SY7104-8?

Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing confirmed at quote time.

Will 5SY7104-8 drop into a panel specified for 5SY4140-7?

Both are 1-pole SENTRON MCBs in 18 mm width, same DIN-rail footprint. The key difference is the tripping characteristic: 5SY7104-8 is D-curve (high inrush), while 5SY4140-7 is B-curve (general-purpose). They are mechanically interchangeable but electrically different — verify the branch-circuit requirement before swapping.

MPN
5SY7104-8