AP4 Group
Field Services

AP4 Group Services (formerly TC&E) is a premier field engineering service company specializing in Controls, Exciter, and LCI systems. Our OEM-trained field services engineers specialize in comprehensive field maintenance services and equipment upgrades on both GE aeroderivative and GE heavy-duty gas and steam turbines. We deliver the right engineer for your scope of work every time.


Large Frame Controls Services Upgrades

AP4 Group 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.

Turbine System Upgrades

Power plant personnel look to AP4 Group 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.

Aeroderivative Field Services

From basic troubleshooting to DLE Mapping and mechanical service and maintenance, AP4 Group 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.



Using the latest technology, components, and lessons learned through decades of experience, AP4 Energy 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.