Fieldbus – Exploiting the Full Potential of Frequency Converters

Tuesday, May 26, 2015

Modern frequency converters are intelligent, which enables them to handle many tasks in drive systems. Nevertheless, even now many devices operate with only four data points in a control system or under control of a DDC and act only as speed controllers. This means that operators do not make full use of the many useful functions and do not have access to stored system data.

Bus Post

However, it is easy for users to exploit the full potential of frequency converters by using a fieldbus link, such as BACnet, to integrate them in the control system. With just one hardware data point, users have full access to all objects of the installed frequency converters. Cabling and commissioning are simpler, which leads to cost savings from the installation phase onward. A large volume of data for effective facility management is available. Decoding of collective fault messages allows faults to be diagnosed, even remotely and the right fault correction actions to be initiated.

Better alarm management

Detailed alarm messages simplify the pin-pointing of possible fault causes and thereby provide effective support for remote facility monitoring. Remote maintenance using modems or the Internet allows state and/or fault messages to be displayed quickly, even with remote systems or system components.

Better facility management

The control room operator is able to monitor and adjust all frequency converter settings remotely. Status data, such as the output frequency or power consumption, can be read out and processed at any time. Additional data for effective energy and peak load management is available without additional components.

Lower installation costs

It is not necessary to equip every frequency converter with a display. The user or operator can access all relevant frequency converter data via the control system.

Simplified wiring with 2-wire connections

Unused frequency converter inputs and outputs can be used as I/O ports to integrate other components in the application or building, such as sensors, filters and limit switches, into the control system. In many cases adding additional I/O points are cheaper than installing and programming an external/ additional DDC controler. There is no need for input and output components since a single hardware data point is sufficient for controlling the frequency converter. Monitoring functions such as motor thermistor monitoring, dry pump protection, etc., as well as output and operating hours counters, are available without additional components.

Simplified commissioning

Parameter configuration is performed from the control room. All settings can be copied quickly and easily from one frequency converter to another. A persistent backup copy of the settings can be stored in the display memory. Designers and commissioning staff can document the settings at the press of a button.