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Siemens 5SN6440-8CN — Miniature Circuit Breakers (MCB)

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.

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

5SN6440-8CN — Ratings
ParameterValue
Overvoltage category3
5SN6440-8CN — Mechanical
ParameterValue
Width72 mm
Height90 mm
Depth76 mm

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