UNIT CONTROL SYSTEMS encompass a variety of control functions for the safe operation of machinery. Our team of engineers has extensive knowledge of the control functions of stationary prime movers, the driven equipment and the associated ancillary systems. Utilizing the operational parameters established by the OEM, we retrofit obsolete control systems using state of the art, commercially available PLCs. The Unit Control Panel (UCP) is designed for the specific environment in which it will be located. Usually of painted carbon steel or stainless steel construction, the panel or cabinet is designed with a front or rear entry door. Arranged on the face of the panel can be a Human Machine Interface (HMI), and an assortment of dedicated displays showing key functions of machinery operation. These are typically defined by the client but often include unit speed; lubrication oil, cylinder, and exhaust temperature, unit vibration, and unit load in horsepower (or Kw) to name a few. Synchronization is typically a dedicated display for power gen units. An Emergency Shutdown, ESD button is also a standard on the face of the panel. Many operators also have switches to enable local or remote operation via a Station Control Panel.
Field devices are often wired and terminated on a DIN rack mounted terminal strip. Digital and analog inputs are internally wired to the appropriate input/output modules. The I/O is communicated to the PLC via ControlNet, Ethernet, or other appropriate communication network protocol.
Our retrofit systems often entail the supply of a complete new control panel, complete PLC system, HMI system, and I/O wired to field marshalling terminals. While experienced with Modicon and Siemens PLCs, we have focused on the widely accepted Rockwell Automation’s Allen-Bradley series of PLCs. The ControlLogix 5000 System or CompactLogix, both with Flex I/O and RSLogix 5000 software form the basis of a typical design. We often integrate a Wonderware InTouch HMI or Allen-Bradley’s PanelView to provide clear visualization and operation of the machinery. Ethernet communication to a Station Control System or DCS is also a standard requirement routinely supplied with the upgrade. The complete system is always fully tested with simulation equipment at the factory prior to shipment.
The United Controls Group is a preferred supplier to two major OEMs, Cameron Compression Systems and Rolls-Royce Energy Systems. Our controls portfolio includes reciprocating engines, gas turbine and electric motors typically driving a compressor package, oil pump, or electric generator.
United Controls Group has purchased the rights to the CleanBurn™III legacy control system and offers repair and technical support. While the CleanBurn™III is still operational on over one hundred Cameron engines, United Controls Group has developed a modern successor, namely the CleanBurn™IV. This upgraded product is based on the Allen-Bradley CompactLogix PLC system, complete with an optional A-B color touch screen PanelView HMI. In addition to engine and compressor controls, the CB IV has a sophisticated Air Fuel Ratio controller which biases the turbo charger wastegate to optimize combustion, resulting in improved emissions, and a boarder engine operating range.
UCG staff has significant experience with designing control systems for the following engine / compressor manufacturers:
- Rolls-Royce (RB-211, Avon, Allison) gas turbine packages