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Siemens 5SM9642-0KK — Residual Current Breakers (RCCB/RCBO)

SENTRON 5SM9642-0KK RC Unit, 4-Pole, 40 A, 300 mA, Type AC

MPN5SM9642-0KK

SENTRON 5SM9642-0KK RC unit electronic, 4-pole, type AC, In: 40 A, 300 mA, Un AC: 400 V, instantaneous design, 50 Hz.

Siemens 5SM9642-0KK datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

5SM9642-0KK — Electrical Ratings
ParameterValue
Number of poles4
5SM9642-0KK — Identification
ParameterValue
Product designationRC unit electronic
Product design / constructionInstantaneous
5SM9642-0KK — Other specifications
ParameterValue
At AC40 A
Residual current typeAC
At 40 °C / rated value37.2 A
At 45 °C / rated value37.2 A
At 50 °C / rated value36 A
At 55 °C / rated value34.8 A
At 60 °C / rated value34 A
At 65 °C / rated value33.2 A
At 70 °C / rated value32 A
Tripping fault current300 mA
Supply voltage frequency50 Hz

Product details

The SENTRON 5SM9642-0KK is a 4-pole residual current unit rated 40 A at 400 V AC, with a 300 mA trip threshold and Type AC waveform detection. The 300 mA sensitivity is for equipment protection or fire prevention, not personnel protection. The instantaneous design trips as soon as residual current exceeds 300 mA. The 50 Hz supply frequency is fixed.

Snap-on DIN rail mounting, standard for SENTRON modular devices. The 4-pole width occupies the same footprint as a 4-pole MCB, fitting existing distribution boards.

Frequently asked questions

What is the closest functional second-source for 5SM9642-0KK?

None of the peer parts (5SL4363-7, 5SL6016-7KL, 5SY4140-7) are direct functional equivalents — they are miniature circuit breakers, not RC units. The 5SM9642-0KK is a residual current device; a second-source would need to be another 4-pole, 40 A, 300 mA, Type AC RCD from a different manufacturer, not an MCB.

Will 5SM9642-0KK drop into a panel specified around 5SL4363-7 without rewiring?

No — the 5SL4363-7 is a 3-pole miniature circuit breaker, not a 4-pole RC unit. The 5SM9642-0KK has a different function (residual current protection vs. overcurrent protection) and a different pole count, so it cannot be swapped without rewiring and re-coordinating the protection scheme.

MPN
5SM9642-0KK