Product Overview
The Siemens WLETU776 is an advanced Electronic Trip Unit (ETU776) engineered for the WL series of molded case and insulated case circuit breakers, providing sophisticated protection and monitoring capabilities in demanding industrial power distribution systems. As a key component within Siemens’ WL platform, the Siemens WLETU776 delivers LSIG (Long-Time, Short-Time, Instantaneous, and Ground Fault) protection functions, ensuring precise fault detection and response to safeguard electrical infrastructure from overloads, short circuits, and ground faults. This trip unit features a graphic LCD for real-time diagnostics and user-friendly configuration, positioning it as an essential upgrade for applications requiring enhanced visibility into system performance. Its core value lies in enabling predictive maintenance through detailed metering and event logging, which minimizes downtime and optimizes energy management in complex automation environments.
In industrial automation, the Siemens WLETU776 integrates seamlessly with WL breakers such as WLS, WLH, WLL, and WLC frames, supporting ratings up to 200A at 600V for three-pole configurations. This compatibility allows for modular scalability, where the unit’s solid-state design processes signals with high accuracy, voting on protective thresholds to prevent nuisance trips while activating swiftly during faults. By incorporating advanced communication protocols, the Siemens WLETU776 facilitates integration into SCADA and DCS systems, delivering actionable data that enhances operational efficiency and compliance with standards like UL 489 and IEC 60947-2. Its intuitive interface simplifies setup via front-panel controls or PC software, reducing commissioning time and empowering technicians with customizable trip curves.
The Siemens WLETU776 ultimately transforms traditional circuit protection into an intelligent asset, offering substantial value through reduced arc-flash risks and extended equipment life. In high-reliability setups, it supports zonal protection strategies, contributing to safer, more resilient power networks that align with the evolving needs of modern manufacturing and process control.
Technical Specifications
| Product Model | WLETU776 |
|---|---|
| Manufacturer | Siemens |
| Product Type | Electronic Trip Unit (ETU) |
| Series | WL Series |
| Trip Functions | LSIG (Long-Time, Short-Time, Instantaneous, Ground Fault) |
| Rated Current | 200A |
| Voltage Rating | 600V AC |
| Poles | 3 |
| Display | Graphic LCD |
| Metering Capabilities | Current, Voltage, Power, Energy |
| Communication | Modbus RTU (optional PROFINET with accessories) |
| Mounting | Interchangeable in WL breaker frames (WLS, WLH, WLL, WLC) |
| Operating Temperature | -25°C to +70°C |
| Humidity | 5% to 95% non-condensing |
| Dimensions | 10.2 cm x 15.2 cm x 5.1 cm (approximate) |
| Weight | 0.45 kg |
Main Features and Advantages
The Siemens WLETU776 stands out with its comprehensive LSIG protection suite, where long-time delays guard against sustained overloads, short-time functions handle moderate faults with adjustable pickup and delay settings, instantaneous responses trip on severe surges, and ground fault detection isolates earth leaks to prevent equipment damage. This multi-layered approach ensures tailored safeguarding, outperforming basic thermal-magnetic units by allowing precise curve customization via the graphic LCD, which displays waveform captures for post-event analysis.
User-centric diagnostics: The integrated graphic LCD provides instantaneous visibility into metering data—such as phase currents, voltages, power factor, and cumulative energy—enabling operators to monitor load balances in real-time without external tools. For the Siemens WLETU776, this feature extends to event logging with timestamps, facilitating root-cause investigations and compliance reporting, which can cut troubleshooting time by up to 40% in busy control rooms.
Enhanced connectivity and maintenance: Supporting Modbus RTU for seamless data export to PLCs or HMIs, the Siemens WLETU776 bridges legacy breakers with Industry 4.0 architectures, allowing remote parameter adjustments and firmware updates. Its self-testing routines automatically verify sensor integrity during operation, alerting via LED indicators or software interfaces to preempt failures.
Robust construction for reliability: Built with composite materials resistant to environmental stressors, the Siemens WLETU776 thrives in dusty or humid industrial settings, maintaining accuracy across wide temperature ranges. This durability, combined with arc-resistant design elements, positions it as a cost-effective enhancer for safety, reducing incident-related losses while boosting system uptime.
At its core, the Siemens WLETU776‘s competitiveness derives from blending intelligence with simplicity—delivering advanced analytics in an interchangeable format that retrofits easily into existing WL installations. This empowers users to achieve finer control granularity, lower energy costs through demand monitoring, and heightened safety assurance, making it a strategic investment for forward-looking electrical engineers seeking to future-proof their automation ecosystems.
Application Field
In manufacturing facilities, the Siemens WLETU776 integrates into motor control centers (MCCs) to protect variable frequency drives (VFDs) and conveyor systems from inrush currents and phase imbalances, where its short-time delay settings prevent premature tripping during startup peaks, ensuring continuous production lines while capturing energy usage trends for efficiency audits. This addresses common challenges like harmonic distortions from non-linear loads, optimizing power quality in automated assembly environments.
Data centers and IT infrastructure deploy the Siemens WLETU776 within uninterruptible power supply (UPS) feeders, leveraging its ground fault protection to isolate faults in redundant circuits without cascading outages. The unit’s metering capabilities track power consumption across server racks, solving visibility issues in high-density setups and supporting green initiatives by identifying underutilized loads for reconfiguration.
Renewable energy installations, such as solar farms, utilize the Siemens WLETU776 in inverter string protection, where instantaneous trips safeguard panels from string faults amid fluctuating irradiance. Its graphic LCD aids in diagnosing shading-induced imbalances, resolving intermittency problems and facilitating predictive maintenance to maximize photovoltaic output under varying grid conditions.
Commercial buildings and HVAC systems benefit from the Siemens WLETU776 in chiller and pump protections, with long-time functions calibrated for seasonal loads to avoid nuisance interventions during peak demands. This targeted application mitigates overcurrent risks in zoned distribution, enhancing tenant comfort while enabling facility managers to analyze historical data for retro-commissioning opportunities.
Across these sectors, the Siemens WLETU776 confronts specific hurdles like regulatory demands for arc-flash mitigation and the push for smart grid integration, providing resilient, data-rich protection that not only averts disruptions but also informs strategic upgrades, driving sustainability and cost efficiencies in electrified operations.
Related Products
- WLETU745: A basic LSIG trip unit in the WL series, offering similar 200A rating to the Siemens WLETU776 but without graphic LCD metering, ideal for cost-sensitive applications needing core protection without advanced diagnostics.
- WLETU762: Enhanced LSIG variant with integrated neutral protection, complementing the Siemens WLETU776 in four-wire systems for better imbalance detection in unbalanced loads.
- WL3646: Complete 3-pole WL breaker frame (400A) that houses the Siemens WLETU776 trip unit, providing higher capacity enclosure for medium-voltage distribution upgrades.
- WL2230: Compact 2-pole WL breaker compatible with the Siemens WLETU776 for lighter loads, serving as a branch circuit option in sub-panel configurations.
- 3VA2710-5HL32-0AA0: SENTRON 3VA molded case breaker that can pair with the Siemens WLETU776 style electronics via adapters, offering a more economical alternative for non-WL frames.
- ETU755: Entry-level ETU for WL series with LSI functions only, acting as a downgrade from the full LSIG of the Siemens WLETU776 for simpler overload scenarios.
- WLETU776MP: Metering-enhanced version of the Siemens WLETU776, adding power quality analysis for advanced harmonics monitoring in sensitive environments.
- WL4840: High-amperage 4-pole WL frame accommodating the Siemens WLETU776, suited for main service entrances requiring robust ground fault coordination.
Installation and Maintenance
Pre-installation preparation: Before integrating the Siemens WLETU776, power down the associated WL breaker and verify frame compatibility (WLS, WLH, WLL, or WLC) against the 200A rating, ensuring all terminals are de-energized using a calibrated voltmeter. Prepare the site by confirming ambient conditions within -25°C to +70°C and low humidity to protect the LCD, while gathering anti-static wrist straps and torque wrenches set to manufacturer specs for secure mounting.
Installation points: Remove the existing trip unit by releasing the latches and disconnecting internal harnesses carefully to avoid bending pins, then align the Siemens WLETU776 with the frame’s guide rails and press firmly until it clicks into place, reconnecting sensors and control power leads with color-coded matching. Program initial trip settings via the LCD or ETU software, test continuity on all phases, and energize the system gradually while monitoring for fault codes, confirming operational status through self-diagnostics.
Maintenance recommendations: For the Siemens WLETU776, schedule annual visual checks of the LCD for clarity and connector integrity, cleaning dust with dry compressed air to prevent thermal buildup. Download event logs quarterly using Modbus tools to analyze trip histories, recalibrating sensors if deviations exceed 1% via factory standards, and apply firmware updates during planned outages to incorporate protection enhancements. In fault scenarios, isolate the breaker promptly and swap with a tested spare, always documenting changes for audit trails to sustain peak reliability.
Product Guarantee
Siemens guarantees the WLETU776 with rigorous quality validation, including 100% functional testing under simulated fault conditions to affirm compliance with UL and IEC standards, instilling confidence in its protective prowess for critical power systems. This assurance encompasses a two-year warranty on materials and workmanship, extendable through service contracts, alongside lifetime technical expertise from our global support network to guide installations and optimizations. Customers receive priority access to repair centers for swift resolutions, minimizing operational interruptions and maximizing ROI through reliable performance. Our dedication shines in proactive resources like online configuration tools and training modules, ensuring the Siemens WLETU776 evolves with your needs. Selecting the Siemens WLETU776 means partnering with a leader in electrical innovation, where unmatched durability and customer-centric service deliver enduring value and peace of mind in every protected circuit.
GE PC Board Card IC3600AIAD1C1C OBSOLETE
ABB Measuring Card 3BSE004940RI 10564992 NEW
NEW RELIANCE 0-57411-1A RESOLVER 0 57411 1A 0574111A
INDRAMAT AC SERVO LINE FORMER NAM1.3-08 NAM 1.3-08
Toyoda TOYOPUC FB2N TOYOPUC-FB2N TFC-2804 TFC2804
GE Power Supply 531X111PSHAKG3 F31X111PSHAJGIFR00/0
GE PC Board Card IC3606SIIA9A IC3606S11A9A NEW
GE PC Board Card IC3600LRDH1B1D006/06 IC3600LRDH1B NEW
Ameritherm Inc. Circuit Board Card 003-0325 Rev. B NEW
YASKAWA V7-4X CIMR-V7CU47P5 VARIABLE FREQ DRIVE 14 kva
Modicon Primary Adapter PCP MM-32PR-000 MM32PR000 NIB
GE PC Card ic3600 IC3600AIAD1B IC3600AIAD NO DOA’S
TOYODA Board Card Module PC3JB-I/O PC3JB 60201H0021 NEW
NEW GE PC IC3600 Board Card IC3600AIAD1C1D IC3600AIAD
