Skip to main content
Siemens 5SM3746-4 — Residual Current Breakers (RCCB/RCBO)

Siemens 5SM3746-4 SENTRON RCCB, 63 A, Type B, 4-Pole, 500 mA

MPN5SM3746-4

Siemens SENTRON 5SM3746-4 RCCB, 4-pole, 63 A, Type B, 500 mA, short-time delayed, 10 kA, DIN rail.

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

5SM3746-4 — Electrical Ratings
ParameterValue
Number of poles4
Overvoltage categoryIII
5SM3746-4 — Identification
ParameterValue
Product designationRCCB
Product design / constructionShort-time delayed
5SM3746-4 — Mechanical
ParameterValue
Mounting positionany
Width in modular units4
Maximum45 °C
Minimum-25 °C
Width72 mm
Height90 mm
Depth77 mm
Installation depth70 mm
5SM3746-4 — Environmental
ParameterValue
IP degree of protectionIP20, if the distribution board is installed, with connected conductors

Product details

The short-time delayed design (selective type) provides coordination with downstream devices, letting fault currents pass briefly to avoid nuisance tripping on transient surges while still clearing persistent ground faults.

Rated at 63 A continuous at 40 °C and 45 °C, derating to 60.48 A at 50 °C and 50.4 A at 70 °C — the thermal curve matters if the panel runs hot. The 10 kA short-circuit current rating (SCCR) per IEC 61008-1 gives the fault-clearing capacity at the device terminals; under EN 60898 the rated breaking capacity is 0.8 kA, which is the standard for domestic RCCBs. The Type B characteristic detects AC, pulsating DC, and smooth DC residual currents up to 1 kHz — required where variable-speed drives, UPS systems, or photovoltaic inverters are on the load side, since those can generate DC fault currents that a Type A or AC device would miss. The 500 mA rated residual operating current (IΔn) is higher than the standard 30 mA for personal protection; this unit is intended for equipment protection or fire prevention in circuits where nuisance tripping from leakage currents (long cable runs, filter capacitors) would be problematic. The short-time delayed switching function (selective RCCB, type S) coordinates with downstream 30 mA RCCBs so that only the faulted branch trips, keeping supply to healthy circuits.

The 72 mm width (4 MW) matches the SENTRON modular grid.

Frequently asked questions

What is 5SM3746-4 used for?

It is a 4-pole Type B RCCB rated 63 A / 500 mA, used for equipment protection and fire prevention in circuits with VFDs, UPS, or PV inverters that can generate DC residual currents.

Where can I buy 5SM3746-4 and how is it quoted?

Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.

Will 5SM3746-4 drop into a panel specified around 5SL4363-7 without rewiring?

No — 5SL4363-7 is a miniature circuit breaker (MCB), not an RCCB. They serve different protection functions and are not direct substitutes. The 5SM3746-4 occupies the same 4 MW DIN-rail footprint but requires a neutral connection for the residual current sensing circuit.

MPN
5SM3746-4