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Siemens 5SN6440-8CN — 4-Pole MCB (DIN Rail)

Siemens 5SN6440-8CN SENTRON MCB, 4P D 40A, 6kA

MPN5SN6440-8CN

Siemens SENTRON 5SN series, miniature circuit breaker, 4-pole, D tripping characteristic, 40 A rated current, 6 kA breaking capacity at 400 V AC, order code 5SN6440-8CN.

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

Specifications

5SN6440-8CN — Identification
ParameterValue
Type / order code5SN6CN
Brand nameSENTRON
5SN6440-8CN — Ratings
ParameterValue
Number of poles4
Pole configuration4P
Rated current (In), AC40 A
Rated voltage, AC (multi-phase)440 V
Rated voltage, DC (max.)60 V
Voltage typeAC
Rated frequency50 Hz
5SN6440-8CN — Protection
ParameterValue
Tripping characteristic (trip curve)D
Rated breaking capacity (Icn), per EN 608986 kA
Overvoltage category3
Degree of protection (IP)IP20, with connected conductors
Neutral conductor switchingNo
Touch protectionYes
5SN6440-8CN — Mechanical
ParameterValue
Width in modular units4
Width72 mm
Height90 mm
Depth76 mm
Installation depth70 mm
Mounting positionany
SealableYes
5SN6440-8CN — Environmental
ParameterValue
Halogen-freeYes
Silicone-freeYes
Influence of ambient temperature (derating)Periodically +55°C, max. 95% humidity

Product details

Rated for motor and high-inrush loads

The 76 mm depth plus 70 mm installation depth means it clears most shallow enclosures; check your gland-plate clearance if the panel is under 100 mm deep. Terminal capacity accepts 0.75 to 25 mm² solid or stranded, with a tightening torque of 2.5 to 3 N·m — no special crimp tool needed for the larger wire sizes. Mounting position is any, so vertical busbar or horizontal feed both work. IP20 with connected conductors is the usual for a panelboard device; no washdown rating, so keep it inside the enclosure.

Frequently asked questions

What does the D tripping characteristic mean for this 40 A breaker?

The D curve (magnetic trip at 10–14× rated current) is designed for loads with high inrush, such as motors, transformers, and discharge lighting. It will pass a starting surge that would trip a B or C curve, while still clearing a hard short circuit within the 6 kA rating.

What wire sizes fit the terminals on the 5SN6440-8CN?

The screw terminals accept 0.75 to 25 mm² solid or stranded copper, with a recommended torque of 2.5 to 3 N·m.

Where can I buy the 5SN6440-8CN and how is it quoted?

This part is sourced and quoted to order against an RFQ through independent industrial distribution. Availability and current pricing are confirmed at the time of quotation — no stock or price figures are published here.

MPN
5SN6440-8CN