Invertek Identifies, Fills Niche

A Company Spotlight on British AC VFD manufacturer and two of its most important recent projects

U.K.-based Invertek Drives Ltd. designs, manufactures and markets electronic variable-frequency drives (VFDs) for controlling electric motors. It was established in Welshpool, U.K., in 1998 when its board of directors identified a niche in the market for a range of compact high-performance VFDs that are easy to use and applicable around the world. The independently owned company now exports more than 90% of its products to more than 80 countries through a network of carefully selected international sales partners and joint ventures. All of its operations, including R&D, are accredited to ISO 9001:2008, while its “Environmental Management System” is accredited to ISO 14001:2004.

Invertek’s VFDs solve a number of different issues in a variety of applications, but they predominantly focus on improving motor control, while saving energy and, therefore, reducing costs. The company believes its VFDs have what it calls “enormous potential around the world,” since they can reduce energy consumption by up to 50%, considering that approximately 70% of the world’s electricity is used by electric motors in industrial applications.

The company manufactures the Optidrive elevator drive, designed to provide smooth, reliable carriage control in all elevator applications in either closed or open loop, and with geared motors or gearless permanent-magnet motors. Other features are:

• Wireless comissioning and perimiter backup
• Independent S-ramps allowing fine tuning of ride performance and jerk-free travel
• Short floor operation to reduce car travel time
• High motor-switching frequency (maximum 32 kHz) for quiet motor operation
• Dedicated motor brake control algorithm for safe and smooth operation of the elevator
• Anti rollback
• Rescue-mode operation (with external uninterruptible power supply)
• Onboard simple programmable-logic-controller function that allows writing of custom programs and interfacing with a wide variety of control systems
• Modbus RTU and CANopen as standard
• Full load operation up to 50ºC with no de-rating
• TÜV-approved “Safe Torque Off” function built in
• Output contactor control for Safety Integrity Level 3 compliance
• Meets recognized international design standards for CE (Europe), UL (USA) and CTick (Australia)

Invertek employs 190 people worldwide, including approximately 150 at its Welshpool headquarters. It operates from purpose-built facilities that include a dedicated “Innovation” department, a “Materials Centre” that houses all components, a logistics facility and an “Express Centre,” which handles all aspects of the assembly, packaging and dispatching of products ordered to meet shorter delivery times than the standard lead time. In addition to dedicated drives for heating, ventilation and air-conditioning building services and energy-efficient pump control, it sells products into industrial automation markets around the world. Other industrial sectors the company constantly evaluates include marine, combustion air fan control and general automation.  

Invertek Drives Sales and Marketing Director Rhydian Welson commented:

“Invertek Drives launched its dedicated elevator drive, Optidrive, in response to the growth opportunities offered by the global elevator sector. Since the product’s launch in 2014, the company has seen a positive ramp-up in orders, and Invertek is working together with a number of key OEMs to further grow the profile of the Invertek brand.

“Optidrive was designed to allow control of globally manufactured elevator motors, rather than a certain make or model. This becomes most attractive for OEMs and system integrators requiring one product for the many different motors that are encountered in the elevator industry. 

“As is well known in the elevator world, the application demands and technologies are continually evolving. Invertek is 100% committed to continuing to innovate and enhance to ensure the expectations from the customer are fully satisfied and that Optidrive stands out from the crowd.”

The ambitious company also plans to increase its share of the global industrial automation market, the plans for which are a reason it is exhibiting at Interlift this month.

Solar Lift Integration in Greece

Invertek’s AC Optidrive product makes Greek company Mezolift’s solar lifts possible. Each installation includes one of the single-phase units with optional incremental/EnDat encoder feedback interfaces, which allow compatibility with a wide range of motors. The traction elevator is primarily used in small apartments and houses up to four stories. The brainchild of mechanical engineer Yiannis Sachsamanoglou from Kilkis, Greece, the product uses up to 80% less energy than conventional lifts and is planned for use in taller structures.

Sachsamanoglou explains:

“Each lift produces the required power and energy from a small autonomous photovoltaic assembly. This is a genuinely energy-autonomous machine that can be used up to 30 times a day and work for three days without charging. Of course, because of our environmental stance, the lift components, including the Invertek VFD, must be eco-friendly, too.”

Theodore Amiridis, Automation Experts’ Technical director and Business Development manager for North Greece, adds:

“Invertek’s elevator drive has a tiny sub-10-W demand on standby, compared to the 30 W typically required for other manufacturers’ VFDs under similar operational conditions. What’s more, the software and parameter groups are easy to handle, and the single-phase input operation means Mezolift elevators can operate in a wide range of buildings, including those using domestic-rated power supplies.”

New Delhi

Invertek reported in July that it alleviated an issue with the passenger lift at the prestigious Rajkamal Banquet Hall in New Delhi. The company’s sales partner in India, Tros Autotek Pvt. Ltd., was approached by one of the country’s leading elevator manufacturers following reports that the lift serving eight floors in the newly constructed banquet hall felt uncomfortable to travel in, and customers were complaining.

A variable-speed drive from another manufacturer had already been installed to control the 7.5-kW permanent-magnet gearless motor but was not performing as expected. Users were experiencing uncomfortable jerks when the lift started and stopped, as well as vibrations during the transition from high to low speed. Tros Autotek Commissioning Engineer Ashok Patil explained:

“The entire ride quality was not very good, and there was one short floor where the parking was located [that] was particularly bad. A jerky elevator ride is never pleasant, but in this case, it could have damaged the banquet hall’s business – diners do not want to be thrown around following a meal!

“Like all AC Drives from Invertek, the elevator drive is very easy to install and commission, and it doesn’t take up much space. The ride quality is now spot on throughout the entire journey with smooth start/stop changeovers and no vibrations. Our customer noticed the difference as soon as the new drive was up and running and is very happy. He said ‘The elevator is working to my satisfaction in all conditions.’”