Advanced Control Systems (ACS) has announced the successful deployments of a first-of-its-kind upgrade solution for one of the most widely used substation remote terminal units in the electric sector.
The GE D20 substation controller, originally developed by Westronic and later produced by the Harris Corporation, has been a mainstay in the substation RTU market for many years. As these RTUs age and reach end-of-life status, thousands of them are being targeted for replacement. Utilities are seeking a more open and secure automation solution for these substations, but going the traditional replacement route is costly and labor intensive, requiring re-engineering of drawings, re-termination of field wiring and sometimes lengthy outages.
ACS' NTX-U20 controllers are an in-place upgrade solution for the D20 I/O panels, delivering significant cost savings versus full D20 replacement because they mount directly to the existing WESTERM termination panels used by the D20. This design eliminates the need to replace field wiring or add marshalling cabinets. This can save the typical utility up to 60 percent of the cost compared to a full replacement.
ACS has developed versions of the NTX-U20 for replacement of the four primary D20 I/O modules – the 'A' (analog), the 'S' (status), the 'K' (control) and the 'C' (combination). Using the NTX-U20 controllers eliminates the proprietary protocol used between D20 panels, instead using a DNP3 over IP link that opens up the system to support the requirements of the modern digital substation.
ACS is the first to successfully deploy an in-place upgrade solution for the D20, with NTX-U20 installations at Duke Energy, MidAmerican Energy, Oklahoma Gas & Electric, Montana-Dakota Utilities and others throughout the United States.