An integrated motor protection switch provides the new system, which consists of a cabinet equipped with a CFW701 frequency converter, with redundant motor protection to ensure reliable and long-lasting operation. In the event of a frequency converter failure, the CFW701's output relay connects the motor directly to the mains power supply via an external bypass circuit. A switch on the front of the cabinet allows the user to configure the bypass function to switch manually or automatically to bypass mode in case of a failure. This self-contained system is particularly well-suited for the reliable and energy-efficient control of induction motors used to drive pumps or fans in HVAC systems in hospitals, airports, office buildings, shopping centers, and other facilities.
The CFW701 integrates a maintenance switch, allowing the frequency converter to be changed, tested, or programmed while the motor continues running through the bypass. Controls on the front of the enclosure allow the user to issue start and stop commands through the frequency converter and the bypass circuit. The CFW701 incorporates a fused disconnect switch, eliminating the need for additional protective components such as circuit breakers or fuses. The enclosure also boasts a high short-circuit capacity without additional components, covering the range of 35 kA to 100 kA. The control and power sections are located in the enclosure below the frequency converter to prevent accidental contact with live components during CFW701 operation. All system components are part of the automation product portfolio and comply with UL508a. The enclosure achieves IP20 protection in the standard version. The CFW701 is also available in versions conforming to IP21 or NEMA 1 protection standards.
The CFW701, equipped with a programmable logic controller and integrated human-machine interface, is ideal for HVAC applications in the 5.5 kW to 110 kW power range. Its user-friendly display shows specific physical units, such as bar, mbar, and m³/h. The variable frequency drive software includes three integrated PID controllers for enhanced process monitoring and greater accuracy. A special "fire" mode prevents the motor from shutting down when the drive detects critical operating conditions, such as excessive temperatures inside the device. This "fire" mode is typically used for demanding applications, such as smoke extractors and fans. Even in its basic configuration, the CFW701 features interfaces for integrating common communication and home automation systems, such as BACnet, MetaSys N2, and Modbus RTU. The device's plug-and-play design makes installation and commissioning extremely easy. The CFW701 with integrated bypass function also takes full advantage of speed and frequency control to maximize the efficiency of the controlled motor.
The WEG CFW701 series is currently available in the following five power ranges: from 5.5 kW to 7.5 kW, from 11 kW to 15 kW, from 18 kW to 30 kW, from 37 kW to 45 kW and from 55 kW to 110 kW.
