Facility Controls Modernization - RTU Replacements

TC Energy Midwest States



Entech provided design services for a large, systemwide, RTU (Remote Terminal Unit) replacement program to upgrade obsolete and maintenance -intensive Bristol 3330 RTUs for twenty-eight (28) facilities in four (4) different States. TC Energy determined that new Control Wave Micro or AutoPilot Pro would be installed to improve system reliability and reduce maintenance costs. By bundling similarly scoped projects, this client recognized significant design cost savings while improving construction and engineering consistency.

Solution Details

To effectively upgrade this collection of facilities, Entech collaborated with TC Energy to identify the modification scope for each site and RTU upgrade. After reviewing a library of existing documentation and as-built drawings, Entech provided solutions for RTU upgrades located both within existing structures and standalone exterior units. Site visits were performed to evaluate the accuracy of the existing documentation and verify the presumed scope. This scope included the evaluation of existing conduit/wiring and RTU locations regarding local electrically hazardous areas.

Construction documentation and drawings were provided for each location, including updated P&IDs, demolition plans, overall site drawings, loop diagrams, electrical plans, and section drawings. Upgrades included new conduit/wiring and replacement of existing transmitters with smart transmitters to improve overall process communication and accuracy. In addition, Entech provided hazardous classification evaluations and updated existing hazardous classification drawings, and/or created new hazardous drawings when required.

Services Provided


  • Site review and demolition drawings
  • P&ID upgrades
  • Update to include all newly added smart transmitters
  • Transmitter Upgrades
  • Upgrade older transmitters that are incompatible with HART Protocol
  • Added transmitter to additional meter runs
  • Wiring and Conduit upgrades
  • New conduit routing and overhead tray design
  • Existing capacity review and confirmation
  • RTU upgrades
  • Loop Diagram design
  • Retrofit, Relocation, and New installation design
  • Battery charger relocation and rack design
  • Evaluation of electrical hazardous classification areas
  • Ventilation design for classified buildings 


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28 facilities

4 states encompassed

By Service