Emergency Call Out

Operating out of our Sheffield Factory facility a genuine 24/7/365 service is offered with access to experienced Project Managers, Technical Authorities and hands on support as required.


As induction Motors & Generators are the workhorses of industry Long Term Service Agreements give additional confidence in the plant availability. With tailored processes geared towards the duty cycle these agreements can be flexible enough to perform under present day requirements.

Project Management

Project Managers within RE Field Services have a wide range of experience of many different types of Motors, Generators and their associated systems. Within the realms of a Major outage, RE Field Services can offer a full cradle to grave Project Support including all QA, Safety and Authorised Person activities.

Site Surveys

Site requirements and workscope development are part of the services offered and these are tailored via initial site surveys and client meetings. The Site surveys allows the plant to assessed and workscopes identified all conducted by our experienced Project Managers & Supervisors.

HV testing

A range of HV testing from Low Voltage Insulation resistance test to High Voltage Tan Delta can be completed from our mobile Site Service Units which come to site fully self contained complete with their own Diesel Generator.


From straight forward minor wiring repairs to full rewinds RE Field Services can offer a broad spectrum of repair options allowing early Return To Service.

Strip and Rebuilds

Stripdown on machines can be completed either in-situ or within the facility at Pinfold Works. Boasting some 13000sqft and in house craneage up to 15Tonnes (supplemented by Megalift systems enabling up to 100T to be accommodated). Full rebuilds can be completed within the factory and on site outage support.

Installation and Alignment

Our installation team can fully install machines whether new, replacements or Return To Service projects. Full alignment of machines to tight modern tolerances to Gearbox or Turbine datum's.

Vibration Monitoring

Monitoring of vibration to allow assessment of potential problems or misalignments can be completed and include analysis and fault finding.

Thermal Image Surveys

Thermal Image surveys allow the plant to continue running whilst inspecting the machinery for any evidence of external hot spots, leaks, & pipe/vent blockages. A detailed survey can help pinpoint shutdown & outage requirements plus any emergency interventions.

Independent Witness Testing

Factory & Site Acceptance Tests (FAT & SAT) are often offered on new or refurbished equipment and RE Field Services can offer the necessary skills to ensure that the product you purchase is the one that you receive.


Consultancy on both Mechanical & Electrical aspects of Electrical Rotating equipment from routine maintenance scheduling to root cause analysis.

Expediting and Quality Adherence Services

Expediting & QA services by experienced Project Managers and Technicains can be offered for Electrical Rotating equipment and associated plant.

Rotor and End Ring Repairs

Rotor recovery techniques are used on Induction motors including damper winding repairs, broken rotor bar replacement and end bell removal and upgrade. Fully Generator rewinds and upgrades can be undertaken on a range of OEM machines.

Complete Rotor Rebuilds

Restacking of Rotor cores and lamination replacement can be completed in house along with full rebuilds and balancing.

Complete Stator Rebuilds

Damaged Stator cores can often be recovered via restacking and lamination replacement techniques allowing potentially written off Machines to be Returned To Service

Complete Rewinds both AC and DC machines

Machine rewinds can be undertaken to replicate existing windings or upgrade designs using modern materials and techniques, Best Industry practice is applied to rewind designs.

Core Repairs

Restacking of Cores and lamination replacement can be completed in house along with full rebuilds and balancing.

Repair and Replacement of commutators / slip-rings etc.

Commutator skimming and undercutting can be completed as well as the full repair and replacement.

Shaft Straightening, Repairs and Replacement


Repairs and Bedding in of White Metal Bearings

White Metal Bearings can often be subjected to damage due to lack of oil, dry starts or other operational anomalies. Repair and subsequent bedding in of the bearings is completed as part of a Major or Partial overhaul workscope

Manufacture and Replacement of seals

Older manufactured machines often utilised in house bearings & seal arrangements which are no longer supported therefore RE Field Services can back engineer and update the seal designs utilising modern materials.

Bearing Replacement Rolling Element and White Metal

In the eventuality that a bearing completely fails RE Field Services can examine and identify the bearing with a modern equivalent and make any alterations that maybe required to the pedestal or housings.

Manufacture and Repair of Fans, Cowlings, Couplings, Guards and Casings

Often during service, parts wear or get damaged due to material ingress or operational incidents. Finding damaged parts during inspections, RE Field Services can repair or replace parts using modern welding and mechanical repair techniques.

Pressure Water Cleaning

Facilities are offered within RE Field Services for the Pressure Water Cleaning of electrical equipment. Prior to any major overhaul the equipment will be thoroughly cleaned using approved  electrical detergents.

Controlled heat – Drying (Stator / Rotor)

A large stoving oven facility exists within Re Field Services capable of  controlled Drying processes on large stators & Rotors up to 6m in length.

Painting, Dip and Spray Varnishing

Utilising modern approved paints and varnishes machines can be overhauled and dipped within the facility

Controlled Paint Removal – Soda Blasting

Environmentally friendly techniques of soda blasting allows the paint to be removed and any integral cracks or deformations become clearly visible without evident change in the structure.

Rotor End Bell – Repairs and Replacement

The removal of the turbo generator rotor end bells and steel wedges requires to be conducted under controlled conditions utilising bespoke equipment and processes.

The end bells will then be tested ultrasonically to determine their long term fitness for use and reinsulated.

Windings can be cleaned to remove carbon and other contaminants and damaged insulations and blocking supports can be repaired or replaced.

RSO Diagnostic testing can be conducted throughout all stages of the process.

Re – Wedging

Applicable to both Stator & Rotors the wedges can be mapped and replaced as required. Modern materials and techniques can elongated the life of the machine and reduce potential downtime.

Concentricity Testing

Vibration on machines can often be caused by bowing or hogging of the shaft. Concentricity testing is completed on Generator & Motor rotors of all speeds and sizes.

Inspection and Testing of Rotor Bars

Matching of Rotor Bars and their repair can substantially reduce down time 

Reflective Surge Oscillograph (RSO)

RSO is a useful electrical test used on Generator Rotors where the windings are symmetrical predominantly 2 pole turbogenerators. Comparison of two reflected signals on either pole of a 2 pole winding can determine its continuity and location of possible interturn faults.

Tan Delta Winding Tests

Tan Delta Winding Test will determine the state of the insulation on a High Voltage winding and it’s ability to maintain a charge. The individual & combined phases can be tested during routine maintenance and results compared thus instulation state can be assessed.

Flash Testing

Flash Testing evaluates whether the electric insulation section of an electric motor or generator has sufficient dielectric strength for the working voltage (sometimes known as dielectric withstand or hipot test). This test is applied at varying levels dependant on the age and service of the machine and not recommended for older windings.

On Line Rotor Tests (IMCA)

Induction Motor Current Analyser (IMCA) is a test that completes a spectrical analysis of a Induction Motors supply current to test for cracked rotor bars while the machine is running in service.

Providing that the design of the Rotor and number of bars is known  then electrical defects, such as cracked rotor bars or shorting ring can be detected.

Flux Testing for Core Integrity

During the Rewind process, of  a generator or motor, the Stator Core requires to be stripped of  all the old coils leaving bare core laminations. During the actual failure the core maybe damaged resulting in shorts  between the core laminations thus causing “hotspots” especially in the teeth and inner bore areas of the stator.  A Core flux test using HV cables wrapped round the core and energised to electrically saturate the core allows a thermal image survey to be completed and areas of concern identified. Subsequent the core can be etched or restacked to eradicate these hot spots.

Insulation Resistance/Polarisation Index

The Polarization Index (PI) Test provides an Indication of the degree of contamination and moisture of the insulation on a High Voltage Winding. Utilising a HV DC Insulation Tester the test can be used as a comparative tool or as a standalone assessment of a High Voltage Winding condition. Working to National & International Standards the winding can be assessed and customers advised of required further works

Portable Appliance Testing (PAT)

Accessing customer sites and using equipment is only possible if the electrical devices have been PAT tested in advance. This service is offered both externally & internally to provide approved equipment.

Mobile Diagnostic Off-line VLF ‘Withstand’ and Tan Delta Testing Services

RE Field Services Ltd. is expanding its comprehensive electrical test services by introducing Very Low Frequency (VLF) AC ‘Hi-pot’ and Tan Delta (TD) diagnostic testing in accordance with internationally recognised IEEE 400.2 and IEEE 433-2009 standards. Our new, highly portable 60 kV rated VLF off-line HV diagnostic test set enables us to detect insulation problems at installation, commissioning and maintenance testing stages on land and subsea MV cables rated up to 33 kV and rotating machines rated up to 11kV. Testing with RE Field Services VLF power supply is a perfect marriage of DC ‘Hi-pot’ test set portability and AC voltage stress distribution across insulation similar to real operating conditions rotating machines and MV power cables are experiencing during normal service life.

Vibration Spectrum Analysis

Utilising the latest vibration analysis tools Vibration Spectrum Analysis can be completed with source and resolution of issues reported.

Endoscope Video Inspections

Access to Generators is extremely limited when the Rotor is in pace and outage period constricted to reduce down time. As such Endoscope (or Boroscope) Inspections are completed on the windings and slot core exists where the likelihood of Partial Discharge deposits or failure are most likely to occur. These images can determine whether further repair or remedials works are required.

Wedge Tightness Mapping

The High Voltage Coils of  Generators and Motors are held in place we either full or partial slot length wedges. Migration of these wedges can be indicative of failures in the insulation and packing below or cause the coils to move & fret the insulation. The Mapping is conducted using tap tests on the individual wedges throughout the whole of the stator winding.

Electronic Core Imperfection (ELCID)

The Electromagnetic Core Imperfection Detector or EL CID is a test that is used to detect insulation failures between laminations of stator cores in large motors and generators. Utilised during major Overhauls whilst the rotor is removed, it uses reduced power requirement to detect failures. The alternate Core Flux test can also be completed by RE Field Services and offered both in house & on site whenever practicable.

Magnetic Particle Inspections (MPI)

Magnetic particle Inspection (MPI) is a non-destructive testing (NDT) process for detecting surface and slightly subsurface discontinuities in ferromagnetic materials and is performed to standards such as EN473 and ISO9712.

Alignment Checks

Rotating Electrical Equipment by its dynamic nature is sensitive to axial & rotational positioning which if incorrect can lead to vibration and other associated issues. Alignment checking is therefore fundamental to the set up of the rotating equipment.

Liquid Penetrant Inspections (LPI)

Liquid Pentrant Inspection (LPI) is a non-destructive testing (NDT) process for detecting cracks and surface discontinuities in metal alloys primarily for use on bearing white metals and bearing casings this technique is often used in works & on site.

Ultrasonic Adhesion Testing (White Metal Bearings)

Ultrasonic Adhesion Testing (UT) is a non-destructive testing (NDT) process for used for detecting metal to metal adhesion  for use on Rotor End Bells and Rotor forging examinations this technique is often used in works & on site.