Product Overview

The Siemens 3VL4731-1DC36-0AA0 is a high performance molded case circuit breaker (MCCB) from the 3VL series, specifically the VL400N frame size. Designed for industrial power distribution and motor protection applications, this 3 pole circuit breaker provides reliable overload and short circuit protection for circuits up to 400 A. The device features a standard breaking capacity (Icu) of 55 kA at 415 VAC, making it suitable for main distribution panels and branch circuit protection in facilities with moderate available fault current.

Equipped with a Thermal Magnetic (TM) LI trip unit, the 3VL4731-1DC36-0AA0 offers long time (overload) protection based on thermal principles and instantaneous (short circuit) protection via magnetic actuation. The rated current (In) is 315 A, with the rated adjustable current (Ir) field adjustable from 250 A to 315 A, providing flexibility to match specific load requirements, while the instantaneous trip setting (Ii) is adjustable from 1575 A to 3150 A in accordance with system coordination studies.

Technical Specifications

Key Features

• VL400N frame construction provides robust mechanical strength for long service life in industrial switchgear and motor control centers.

• High breaking capacity of 55 kA at 415 VAC ensures safe interruption of high fault currents, protecting downstream equipment from damage during short circuit events.

• Thermal magnetic LI trip unit with independent thermal curve for overload protection and instantaneous magnetic trip for short circuit clearance, complying with UL 489 and IEC 60947 2 standards.

• Adjustable rated current (Ir) from 250 A to 315 A allows fine tuning of long time protection to match actual load profiles without changing the circuit breaker frame.

• Adjustable instantaneous trip (Ii) from 1575 A to 3150 A enables selective coordination with upstream and downstream protective devices.

• Compact modular design fits standard 3VL accessories including shunt trips, auxiliary contacts, alarm switches, and motor operators for remote control.

• 3 pole protection with all poles equipped with thermal and magnetic elements ensures balanced protection for three phase systems.

• Front accessible load side terminals simplify wiring and reduce installation time in panel building applications.

• Integrated trip indicator provides visual confirmation of fault type (overload or short circuit) after tripping.

Applications

The Siemens 3VL4731-1DC36-0AA0 circuit breaker is used in industrial electrical distribution systems requiring reliable overcurrent protection for feeders, motor branch circuits, and control panel incoming supplies. Typical applications include main distribution boards in manufacturing facilities, motor control centers powering large pumps and compressors, HVAC equipment feeders in commercial buildings, and industrial machinery power supplies.

This MCCB is also suitable for generator protection in standby power systems, sub main distribution in large facilities, and as a feeder breaker for downstream panelboards. While the standard version does not include auxiliary contacts, the 3VL4731-1DC36-0AA0 can be fitted with aftermarket accessories including the 3VL9431-7DC30 for those requiring remote status monitoring. For system integrators, this circuit breaker provides the safety and performance required for UL listed industrial control panels, ensuring compliance with North American and international electrical codes.