WGQ2-250/4P Medium-Current 4-Pole 250A Load Isolation Type Automatic Transfer Switch

WGQ2-250/4P Medium-Current 4-Pole 250A Load Isolation Type Automatic Transfer Switch (ATS)

Product Overview: Engineered for Mid-Range Power Reliability

The WGQ2-250/4P Load Isolation Type Automatic Transfer Switch (ATS) is a cornerstone device for medium-capacity power distribution systems where continuous operation is essential, but industrial high-current demands (like 400A or higher) are not required. Rated at 250 Amperes (250A) and featuring a robust 4-Pole (4P) configuration, this ATS is specifically designed to manage the critical power needs of medium-sized commercial buildings, large retail centers, schools, mid-tier data centers, and specialized industrial processes.

As a Load Isolation Type (PC Class) switch, the WGQ2-250/4P excels in its ability to make and withstand the high thermal and dynamic forces associated with short circuits, relying on upstream protection devices for fault interruption. This fundamental design ensures maximum structural integrity and contact reliability during system disturbances. It integrates a powerful motorized mechanism and a smart micro-processor control unit to deliver automated, secure, and seamless transfer of electrical power between the Normal Source (Utility Grid) and the Alternate Source (Backup Generator or UPS system). The WGQ2-250/4P is the embodiment of intelligent engineering, offering medium-current capacity without compromising on the high safety and performance standards expected in critical power applications.

Core Features and Performance Advantages

1. Optimal Medium-Current Capacity and Structure

• 250A Current Rating: Perfectly sized for the majority of medium-sized facility main switchboards or critical sub-distribution panels, balancing high load capability with cost-effectiveness.

• 4-Pole Configuration: Provides comprehensive system compatibility for three-phase four-wire electrical systems (R, S, T, and Neutral). Switching all four conductors ensures complete galvanic isolation between the disconnected source and the load, a non-negotiable requirement for system safety and maintenance procedures.

• Load Isolation (PC Class) Design: The switch mechanism is optimized for its primary role: safe power switching and isolation. Its ability to withstand high short-circuit currents ensures that the switch itself is not damaged during a fault, maintaining operational readiness once the fault is cleared by the circuit breaker.

• Compact Industrial Form Factor: Designed for easy integration into standard electrical cabinets and enclosures, featuring a modular structure that facilitates both installation and serviceability.

2. Unrivalled Safety and Mechanical Integrity

• Integrated Mechanical Interlock: The physical architecture of the WGQ2-250/4P incorporates a failsafe mechanical lock that physically prevents the contacts for the Normal Source and the Alternate Source from closing simultaneously. This foundational safety feature eliminates the possibility of inter-source short circuits and back-feeding the utility grid.

• Redundant Electrical Interlock: Supplementing the mechanical interlock, the intelligent control circuit provides a second layer of electrical interlock, actively monitoring the status of both contact sets to prohibit simultaneous operation, thus providing dual-layer protection.

• 3-Position Switching: The main mechanism provides three essential, distinct positions:

  • I (Normal Source ON): Load connected to the utility.

  • O (OFF/Neutral Position): Load is fully isolated from both sources.

  • II (Alternate Source ON): Load connected to the backup source.

• Robust Arc Extinction: Specialized arc chambers and contact housing minimize the duration and intensity of the electrical arc during switching, protecting the contacts from wear and significantly extending the device’s operational life.

3. Smart Automation and Control Unit

• Micro-Processor Based Intelligence: The integrated control module continuously monitors the essential electrical parameters of both sources, including voltage, frequency, and phase sequence consistency.

• Comprehensive Power Quality Monitoring: The unit is programmed to detect common power disturbances (e.g., undervoltage, overvoltage, phase loss, and frequency deviation), ensuring that transfer only occurs when a genuine, sustained power failure is confirmed.

• User-Configurable Time Delays: To ensure system stability, the controller allows for the setting of crucial time delays:

  • Source Availability Delay: Prevents premature switching when a source briefly returns after an outage.

  • Transfer Time Delay: Allows the load to stabilize before connecting to the new source.

  • Engine Start/Stop Delays: Optimizes the performance and lifespan of the connected backup generator.

• Remote Signaling and Communication: The control unit typically features auxiliary contacts for status reporting and may include RS485 communication ports (using Modbus protocol) for remote monitoring, diagnostic data logging, and integration into Supervisory Control and Data Acquisition (SCADA) or Building Management Systems (BMS).

4. Design for Durability and Serviceability

• Industrial-Grade Housing: The core switching mechanism and control unit are encapsulated in durable, flame-retardant materials designed to withstand the harsh conditions of electrical rooms and industrial environments.

• Extended Handle for Manual Operation: The included elongated manual operation handle provides the necessary leverage for safe and compliant manual switching, even when the motorized mechanism is disengaged or during maintenance procedures.

• Clear Visual Indicators: The panel features clear indicators for the status of the Normal and Alternate sources, the current connected position (I, O, or II), and any fault alarms, allowing for quick visual diagnosis.

• High Environmental Adaptability: The device maintains reliable performance across a broad operational temperature range and under specified altitude and humidity conditions, certifying its industrial readiness.

Typical Application Environments

The WGQ2-250/4P ATS is the ideal solution for ensuring power continuity in various mid-range critical applications:

• Mid-Sized Commercial Buildings: Powering essential services like lighting, HVAC controls, and security systems.

• Retail Centers and Supermarkets: Maintaining refrigeration, point-of-sale systems, and security surveillance.

• Educational Institutions and Universities: Securing power for labs, essential computer systems, and emergency evacuation lighting.

• Light Industrial and Manufacturing: Protecting small to medium production lines and quality control equipment from costly interruptions.

• Water and Wastewater Treatment Plants: Ensuring continuous operation of essential pumps and monitoring equipment.

Commitment to Standards and Safety

The WGQ2-250/4P is designed and manufactured in compliance with major international and national standards for low-voltage switchgear and controlgear, including IEC 60947-6-1. This adherence guarantees that the product meets rigorous criteria for performance, safety, mechanical integrity, and electrical endurance, providing users with a certified and reliable component for their critical power infrastructure.

By selecting the WGQ2-250/4P ATS, facility managers are choosing a strategically sized, feature-rich device that delivers industrial-grade safety and intelligence without the excess capacity (and cost) of higher-rated switches, ensuring robust, efficient, and uninterrupted power management.