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Siemens 5SM1644-0 — Residual Current Breakers (RCCB/RCBO)

Siemens SENTRON 5SM1644-0 RCCB, 4P, 40A, 300mA, 400V AC

MPN5SM1644-0

Siemens SENTRON RCCB, 4-pole, type AC, In 40 A, IΔn 300 mA, Un AC 400 V, DIN rail mount, IP20, current production.

$30.80Ref. price · indicative, final on quote
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

5SM1644-0 — Electrical Ratings
ParameterValue
Number of poles4
Overvoltage categoryIII
5SM1644-0 — Identification
ParameterValue
Product designationRCCB
Product design / constructionInstantaneous
5SM1644-0 — Mechanical
ParameterValue
Mounting positionany
Maximum45 °C
Minimum-5 °C
Installation depth55 mm
5SM1644-0 — Environmental
ParameterValue
IP degree of protectionIP20, if the distribution board is installed, with connected conductors

Product details

The Siemens SENTRON 5SM1644-0 is a 4-pole residual current operated circuit breaker (RCCB), type AC, rated 40 A at 400 V AC with a 300 mA tripping residual current. It snaps onto a DIN rail (REG) and fits a 4-module width (4 MW per DIN 43880).

Installation depth is 55 mm. The IP20 rating applies once the distribution board is installed with conductors connected — the enclosure, not the breaker itself, provides the environmental seal. Finger and back-of-hand touch-safe terminals (protection against electrical shock) reduce risk during panel work.

Rated for 50 Hz only. The 40 A rating holds at 40 °C and 45 °C; it derates to 38.4 A at 50 °C, 36.8 A at 55 °C, 35.2 A at 60 °C, 33.6 A at 65 °C, and 32 A at 70 °C. Maximum power loss is 4.8 W. Silicon-free construction (yes) matters for applications where silicone outgassing can contaminate contacts or optics.

Frequently asked questions

Where can I buy 5SM1644-0?

The 5SM1644-0 is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.

What are the key ratings for 5SM1644-0?

4-pole, type AC RCCB, 40 A rated current at 400 V AC, 300 mA tripping residual current, 10 kA SCCR at 400 V AC, 50 Hz only, DIN rail mount, 4 MW wide.

What is the ambient temperature range for 5SM1644-0?

Operating ambient temperature range is -5 °C to 45 °C. Storage and transport range is -40 °C to 60 °C.

Will 5SM1644-0 drop into a panel specified around 5SQ2670-2YA63 without rewiring?

Both are 4-pole RCCBs on a DIN rail footprint, but the 5SM1644-0 is type AC with a 300 mA trip, while the 5SQ2670 series includes type A and different trip ratings. Verify the specific 5SQ2670 variant's type and trip current before assuming a drop-in swap — the physical rail fit is the same, but the protection characteristic may differ.

MPN
5SM1644-0