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TDC Group Announces Acquisition of Parsons Peebles Generation Ltd

TDC Group is pleased to announce its acquisition of the business and assets of Parsons Peebles Generation Ltd (PPGL) in Rosyth. With a trading history spanning more than 120 years, PPGL is a world-renowned manufacturer and repairer of medium & high voltage electric motors and generators. The business also boasts one of the most comprehensive test facilities in Europe, with direct full load testing and capacity at 50 & 60Hz up to 8.0MW for motors and up to 65MVA for generators.

The Rosyth facility will now trade under the name TDC Parsons Peebles Ltd. In addition to the specialist HV skills and experience the staff in the Rosyth location bring to TDC, the facility has a solid customer base in sectors such as oil & gas, petrochemical, marine, nuclear power and renewable energy.

This latest acquisition continues a program of expansion for TDC, which has resulted in the substantial growth of the group over the last two decades. TDC Group supplies a wide range of electro-mechanical services, which include the repair, rewind and refurbishment of rotating electrical machines; electrical engineering and maintenance services with particular specialism in IECEx & ATEX certified equipment; LV, MV and HV cable jointing; and control panel manufacturing. TDC also provides condition monitoring services such as HV Partial Discharge (PD) Analysis, Motor Current Signature Analysis (MCSA), Thermographic Surveys and Primary & Secondary Current Injection Testing.

TDC Managing Director, Neil Milne, commented “this is an exciting opportunity for the TDC Group, as the acquisition of PPGL’s Rosyth facilities will add high voltage manufacturing and repair capabilities to our broad engineering portfolio. This complements our current service and product range and will provide synergistic benefits to our divisions based in Aberdeen, Rosyth and High Wycombe. It also supports TDC’s strategy of delivering single source in-house engineering solutions to customers, for electrical and mechanical manufacturing, overhaul and installation projects, and aftercare asset maintenance. Importantly, this will increase TDC’s competitiveness in the electromechanical rotating equipment field and will allow us to add further value to services offered to customers.”

MV/HV Induction Motors & Generators

Test Facility

Specially equipped to handle medium & high voltage motors and generators, TDC Parsons Peebles can load test Induction motors at 50Hz and 60Hz to BS EN IEC60034 with ratings up to 15MW in accordance with NEMA (US) & IEEE requirements. Conducting condition assessment and full load testing of repaired and new reverse engineered units.

The following outlines the options available for load testing Induction Motors and Generators:

Differential Gearbox, Superposition, Continuously Varied Frequency, Back-to-Back - multiple pole Motors and Vertical Motors.

  • Stator core flux (wound and unwound)

  • Resistance checks hot & cold

  • No load losses and magnetisation

  • Direct Full Load heat runs at rated voltage, speed and power factor coupled through differential gearbox to load machine. Limits are 7.5MW at 50Hz and 8.0MW at 60Hz for speeds of 2, 4, 6 and 8 pole. Generally, most standard voltages from 3.3kV to 13.8kV. Capacity at 3.3kV/4.5MW

  • Outside the range where direct loading is not possible, temperature rise measurement methods are implemented using either Forward Short Circuit Superposition method or Continuously Varied Frequency CVF method “Primary superposed equivalent loading method” IEEE 112

  • Direct-On-line starting capability at both 50Hz and 60Hz using Rosyth facility 40MVA Generator set

  • Locked rotor test and starting torque measurements limited by power that can be provided by the motor-generator set, but up to 2000kW of losses, (mostly rotor loss) in the motor under test

  • Vibration measurement, recording and analysis and balancing on rotor end planes.

  • Purging and pressurising Certification testing of Ex ‘p’ machines for Hazardous Areas

  • Noise testing

  • Winding HV testing using AC up to 33 kV and with 100 kVA capacity. Testing to meet the requirements of ESI 44-3 and EEMUA 132

Overhead Crane Lifting Capacity

  • 1 x 63 Tonnes

  • 2 x 25 Tonnes

  • 1 x 15 Tonnes

Synchronous Machines

TDC Parsons Peebles provides comprehensive load-testing capabilities which offer clients confidence their refurbished or new machines will perform to the design capability upon installation on site.

50 or 60 Hz Synchronous Generators up to 65MVA tested via open circuit zero power factor method.

Testing includes:

  • Balancing of all rigid shaft generators. Two pole flexible rotors can be trim balanced utilising accessible balance planes

  • Open and short circuit loss characteristics

  • Heat runs at rated excitation, Zero power factor up to 40MVA. For all ratings, heat runs can be performed utilising short circuit, open circuit and unexcited runs

  • Sudden three phase short circuit tests, time constants and reactance

  • Overspeed testing of 50Hz and 60Hz machines

  • Winding HV testing using A.C. up to 33kV and with 100kVA capacity

  • Vibration measurement, recording and analysis

  • Certification testing of pressurised motors for hazardous areas

  • Noise measurement

The balancing facility is used for rotors up to 10,000 kgs. Motor and generator rotors can be trim balanced on test if required. Requests for special testing, extending the range available would always receive consideration.

For further information on Parsons Peebles' full service range, please visit

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