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Siemens 5SM3646-8LA — Residual Current Breakers (RCCB/RCBO)

Siemens 5SM3646-8LA SENTRON RCCB, 63A 300mA Type A Selective

MPN5SM3646-8LA

Siemens SENTRON 5SM3 series, selective RCCB (residual current operated circuit breaker), 4-pole, Type A, rated current 63 A, rated residual current 300 mA, rated voltage 400 V AC, DIN rail mount.

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

5SM3646-8LA — Electrical Ratings
ParameterValue
Number of poles4
Overvoltage categoryIII
5SM3646-8LA — Identification
ParameterValue
Product designationRCCB
Product design / constructionSelective
5SM3646-8LA — Mechanical
ParameterValue
Mounting positionany
Installation depth70 mm
5SM3646-8LA — Environmental
ParameterValue
IP degree of protectionIP20, if the distribution board is installed, with connected conductors

Product details

It's Type A, so it catches pulsating DC fault currents on top of standard AC sine-wave leakage, and selective means it's time-delayed to coordinate with downstream RCCBs: a ground fault on a branch trips the branch device first, not this main isolator. Rated at 63 A continuous and 300 mA residual trip, it's sized for a submain or feeder in a commercial or industrial panel. (cites:,).

Mounting position is any — vertical, horizontal, upside down — which helps when you're squeezing it into a crowded enclosure. Terminals accept 1.5 to 25 mm² solid or stranded copper, with a tightening torque of 2.5 to 3 N·m. That's a solid lug range: big enough for 25 mm² feeder tails, small enough for 1.5 mm² control wiring if you're looping through. (cites:,).

Where it lives in the panel

Rated IP20 with the distribution board installed and conductors connected — that's the standard for enclosed panel gear, not for open washdown areas. Finger and back-of-hand safe per the protection class, which is what you expect for a DIN-rail device behind a locked door. Ambient range is -25 to +45 °C operating, with a wider storage band of -40 to +75 °C for warehousing. Overvoltage category III means it's rated for fixed-installation mains-level transients. (cites:,).

Frequently asked questions

What are the key ratings for this RCCB?

Rated at 63 A continuous current, 300 mA residual trip current, 400 V AC, 50 Hz, Type A (pulsating DC sensitive), selective (time-delayed), 4-pole. (cites:,)

What wire sizes does the 5SM3646-8LA accept?

Terminals accept 1.5 to 25 mm² solid or stranded copper. Tightening torque is 2.5 to 3 N·m. (cites:,)

Can I buy the 5SM3646-8LA here 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. (cites:)

MPN
5SM3646-8LA