The surge in Ethernet adoption, combined with lower hardware costs, is rapidly changing how we interact with “smart” control and power devices.

Manufacturing facilities on the road to modernization can incorporate smart devices, such as newer variable frequency drives (VFDs), with little to no retrofitting. This eliminates the need to rip and replace, which can be daunting and expensive.

Modern vs. Legacy VFDs

Incorporating a smart VFD into an older process is easier than you think. A new drive works as a “drop in,” and once set up will offer better monitoring capabilities right away.

New VFDs communicate data to existing systems, like PLCs, PCs and data collection systems making information available to the plant and intranet. Transmission mediums can be existing network cabling or wireless devices.

They are more sophisticated, smaller and less expensive than previous versions. And they contain hundreds of functional and diagnostic data points that can be profiled and used for process optimization.

VFDs using EtherNet/IP are making it easier than ever to access and make use of this data.

Glass Manufacturer Switches to Smart VFD

Here’s an example. A Southeastern machine manufacturer needed a PLC-networked solution to control the speed of a motor that drives a carriage back and forth over a turning roll that melts fiberglass. The furnace housing controls the amount of molten glass on the roll, which is also controlled by a VFD.

In this case, hardwiring a drive to the control panel and running cable to the system was not effective because there would have been at least 13 conductors per drive required to interface with the PLC discrete and analog I/O. Several junction boxes would have been necessary to get this wiring to the bridge where the PLC and HMI are located. They opted for using one Ethernet cat. 5 cable for each VFD connected to the Ethernet switch. This resulted in less wiring and more control of the drive.

Using the newer VFD also allowed them to monitor motor speed in RPM, motor current, and major faults such as overcurrent, overload and overvoltage.

Troubleshooting with VFD Diagnostics

The data from new VFDs can be used to improve both process performance and reliability. It can also be combined with other process data points to yield insight into forecasting and optimization.

Troubleshooting is also easier. Diagnostics are built in, so when a problem occurs the drive communicates the issue as well as its source. This eliminates the need for hand-measuring voltage levels and manually testing for answers.

Another example involves a well-known lighting manufacturer, whose process requires strict cooling requirements. Their traditional VFD was providing feedback that the motor was operational, but in this case they needed diagnostics on the fan, which was apparently nonoperational due to a broken belt.

Using a more advanced drive, in this case Yaskawa’s A1000, the manufacturer was able to monitor torque with established limits to provide actual motor load, which relayed feedback and warnings to the control system. If there was a problem with the fan, the VFD would shut down and a message indicated that corrective actions were required, such as inspect motor and fan for broken pulley or belt. This information was sent to operators’ smartphones or via email.

Yaskawa’s A1000 drive is a top example of a smart drive.

Diagnostics include: