Siemens 3VL6780-2TB46-8TE1 MCCB Unit

Module Feature

3VL6780-2TB46-8TE1 is Siemens SENTRON 3VL VL800 high breaking moulded case circuit breaker.

It adopts 4-pole construction, rated current 800A, H breaking class with 70kA short-circuit breaking capacity at 415V AC. It is equipped with ETU electronic trip unit, supports adjustable overload, short delay, instantaneous and earth fault LIG protection. It can be fitted with auxiliary switch, alarm contact and communication module for remote status upload. This model belongs to end-of-life legacy 3VL series, widely stocked as maintenance spare for power plant, petrochemical and factory low voltage switchgear cabinet.

Working principle

Built-in current transformers sample three-phase and neutral current signals and send data to ETU trip unit.

Electronic protection unit continuously compares measured current with preset protection curves. When overload, short circuit or earth fault is detected, it triggers trip release to separate main contacts and cut off fault circuit rapidly. Operation counter, fault type and time-stamped event logs are stored internally, and data can be uploaded to SCADA via communication expansion module.

Onboard components

Main contact assembly, arc extinguishing chamber, current transformer group, ETU electronic trip unit, thermal-magnetic release mechanism, auxiliary contact block, front operation handle, status indicator window and reinforced insulated housing.

LED indicators

Front indicators show breaker ON, breaker OFF, fault trip status. Detailed protection alarm code and parameter information are displayed on ETU trip unit panel.

Hardware self‑diagnosis

ETU trip unit runs continuous supervision for trip coil continuity, CT signal loss, internal power supply abnormality and hardware failure. Protection parameter setting and fault log reading are completed by Siemens LV configuration software.

Programming softwareSiemens power distribution commissioning tool, used for overload curve, short circuit threshold, earth fault setting and communication address configuration.

Electrical & Process Parameters

Model:3VL6780-2TB46-8TE1 Brand:Siemens Device type:SENTRON 3VL VL800 molded case circuit breaker Function:Overload, short circuit and earth fault selective protection for 4-pole low voltage power distribution circuits

Mechanical & Structure

Mounting:Switchgear cabinet fixed installation Protection class:IP30 front panel, IP20 terminal compartment Housing:Heavy-duty reinforced insulated MCCB housing

Environmental

Operating temperature:-10℃ ~ +55℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:CE, IEC 60947-2 Status:Original Siemens legacy distribution spare

Installation

Isolate upstream power supply before replacement.

Check primary copper bar and secondary control wiring, confirm 4-pole phase and neutral wiring sequence, set protection parameters according to distribution design, test manual/electric tripping and earth fault protection function after commissioning.

Interface

Primary connection terminal for L1/L2/L3/N, secondary screw terminal block for auxiliary contact, alarm contact and communication signal.

Diagnostic

False earth fault trip: CT polarity reversed, neutral loop interference or earth threshold improper setting. Refuse to trip: ETU trip unit damaged, mechanical jamming or contact burnout. Communication offline: Communication module fault, cable damage or station address conflict.

Product Brief

Siemens 3VL6780-2TB46-8TE1 molded case circuit breaker, VL800 800A 4P high breaking spare for industrial low voltage main distribution cabinet replacement.