Virginia-based Defense Holdings, Inc. (DHi) recently announced it has received unrestricted certification from Underwriters Laboratories for its pitch control slip rings with HiPerCon Brand metal fiber brushes.
With this significant accreditation, DHi becomes: only the second company to achieve a UL listing for WTG pitch slip rings; and the first and only company to achieve UL certified and listed WTG pitch slip rings using metal fiber brush technology.
DHi’s UL Certified pitch control slip rings are currently available for use in all GE1.X, GE2.X and Suzlon S88 WTGs. The company’s “T00XXXX” series pitch slip rings are pre-certified to provide design flexibility for current and future slip ring demands for other OEM designs, as well as being capable of incorporating many other features including but not limited to high quality multi-GigaBaud signal transmission capabilities (>100MBPS/channel), high quality transmission of signal over power (PLC requires capable monitoring and control methodologies), and other aftermarket needs such as; blade de-icing or tip illumination, and advanced blade monitoring and control.
DHi entered the wind industry with its revolutionary patented Metal Fiber Brush (MFB) technology in the spring of 2011 under the mentorship of H&N Wind (A Timken Brand Company). Due to the general lack of knowledge throughout the wind industry of the existence and nature of DHi’s HiPerCon Brand MFBs, legacy pitch slip ring carcasses were used in a program through which customers were provided slip rings refurbished with DHi’s metal fiber brushes.
The primary goal was to familiarize the industry with the multitude of benefits associated with HiPerCon Brand patented metal fiber brushes as compared to carbon-based, metal-graphitic, or other metal brush technologies in use at that time. A secondary and very important goal was to demonstrate reductions of operations and maintenance (O&M) costs and increased operational availability.
“We are excited to set new industry benchmarks by becoming the first company in the world to provide the first unrestricted UL certified carbon-free slip rings to the wind industry,” DHi president and CEO Rich Martin said.
— Source: Defense Holdings, Inc.
Developed by Moventas, CMaS condition monitoring service maximizes gearbox life with early detection of mechanical problems through remote, real-time monitoring of gearbox vibration, oil condition, and temperature. A strong majority of all new wind turbines are sold with advance condition monitoring on the drivetrain. Unfortunately, a large majority of the existing fleet of 40,000 wind turbines were built without this valuable technology, and owners find it difficult to afford and deploy.
multi-brand boroscoping and a complete suite of lower cost multi-brand up-tower repairs for the North American fleet,” said Mike Grunow, vice president of Sales and Marketing, Americas at Moventas. 
