BOM / RFQ

Siemens 5SY4403-8 — 4-Pole MCB (DIN Rail)

Siemens 5SY4403-8 SENTRON MCB, 4P D-Curve 35kA

MPN5SY4403-8

Active

Siemens SENTRON miniature circuit breaker, 4-pole, D tripping characteristic, rated 400 V AC, 10 kA (EN 60898) / 35 kA (IEC 60947-2), 76 mm deep.

$340.44Ref. price · indicative, final on quote

Add to RFQ

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

Specifications

5SY4403-8 — Identification
Parameter	Value
Brand name	SENTRON
Application suitability	Mechanical engineering / industry

5SY4403-8 — Ratings
Parameter	Value
Number of poles	4
Pole configuration	4P
Rated current (In), AC	400 V
Rated voltage, AC (multi-phase)	440 V
Rated voltage, AC (single-phase)	440 V
Voltage type	AC

5SY4403-8 — Protection
Parameter	Value
Tripping characteristic (trip curve)	D
Rated breaking capacity (Icn), per EN 60898	10 kA
Rated breaking capacity, per IEC 60947-2	35 kA
Breaking capacity, AC (UL 1077 / CSA C22.2 No.235)	5 kA
Overvoltage category	III
Pollution degree	3
Degree of protection (IP)	IP20, with connected conductors
Neutral conductor switching	No
Touch protection	Yes

5SY4403-8 — Mechanical
Parameter	Value
Width in modular units	4
Width	72 mm
Height	90 mm
Depth	76 mm
Installation depth	70 mm
Fastening / mounting method	Quick assembly system
Mounting position	any
Combined terminal, top	Yes
Combined terminal, bottom	Yes
Tightening torque, max.	75 °C
Tightening torque, min.	-40 °C
Sealable	Yes

5SY4403-8 — Environmental
Parameter	Value
Halogen-free	Yes
Silicone-free	Yes
Influence of ambient temperature (derating)	max. 95% to 55°C, max. 55% to 70°C, max. 35% to 75°C

5SY4403-8 — Performance
Parameter	Value
Mechanical service life (switching cycles, typ.)	10 000

Product details

The 5SY4403-8: It takes 4 modular width units on a DIN rail, 72 mm wide, 90 mm tall, 76 mm deep — the same footprint as other 4-pole SENTRON breakers. The quick assembly system clips onto the rail and accepts bottom and top combined terminals. Touch protection is built in; IP20 with connected conductors is the hands-off spec.

No direct second-source or replacement is needed at this stage. If you're stocking a critical spare, the standard SENTRON shell means the same accessory range (aux contacts, shunt trips, busbars) fits across the 5SY44 family.