AP4 Group – Full-Service Heavy-Duty & Aeroderivative Industrial Gas Turbine Maintenance Provider.

Manage your turbine system with TC&E

The requirements for gas turbine systems control are among the most challenging in the utility industry. To manage and maintain gas turbines in a safe and cost-effective manner requires highly skilled personnel who understand both the turbine operations and the controls system used to support it. 

TC&E can provide those highly skilled personnel to perform general maintenance, troubleshooting, start up support and even DLN tuning. Our field engineers understand not only your turbine controls, but how your turbine fundamentally operates with all the accessory skids and plant BOP.

Our Specialization

TC&E specializes in GE™ industrial and Aero gas turbine control systems. Our gas turbine controls field team is among the industry’s most experienced engineers.

We can help support any of the control systems and HMI’s as listed here:

  • SpeedTronic™
  • MKI
  • MKII
  • MKIV
  • MKV
  • MKVe
  • MKVI
  • MKVIe
  • IDOS
  • Windows HMI (NT, XP, Win7 & 10)
  • Cimplicity Screens
  • VersaMax
  • RX3i
  • 90/30
  • 90/70

Services Offered

Although TC&E does not specifically stock spare parts, we work with several vendors and can usually obtain critical parts in under 24 hours at prices equal to or better than the OEM.

  • I&C calibrations & loop checks
  • Gas Valve, IGV, and Bleed Heat Calibration
  • Startup support pre/post outage
  • Vibrations Monitoring & Calibration
  • DLN Tuning 1.0, 2.0, 2.6 & Liquid
  • HMI file and record organization
  • HMI Backup and Restoration
  • Thermocouple verification
  • Loop & Function Checkout


AP4 Power Services specializes in controls, excitation, and LCI systems on GE™ heavy-duty gas and steam turbines. These services include a wide variety of controls maintenance, troubleshooting, and system upgrades. Our OEM-trained field engineers are here to ensure your equipment operations are reliable and efficient.

Power plant personnel look to AP4 Power Services when they are seeking a trusted non-OEM service provider that can help develop and implement customized controls system projects. We are a trusted installation partner for many non-OEM equipment vendors throughout the industry.

From basic troubleshooting to DLE Mapping and mechanical service and maintenance, AP4 Power Services can meet all of your aeroderivative needs. Our expert team of Controls & Mechanical Field Engineers are ready and able to provide the on-site support you require.

Industry Benefits


Using the latest technology, components, and lessons learned through decades of experience, AP4 Power Services can ensure complete reliability for both start-up and continuous operation.


This is the key to success in today’s competitive power markets. Heat Rate, Capacity, Start-Up, and Maintenance Costs are critical to the success of aging power plants.


Spending good money where it makes the most difference! We understand that O&M budgets are shrinking, so we work with the plants to understand where and when to repair, replace, or upgrade for maximum return.


Aging systems can continue to provide reliable service for many years to come with the proper service, maintenance, and repairs. Push your upgrades out 5-10 years with confidence.