Rotating electric machines are long lasting equipment if followed the known predictive and preventive maintenance programs. Issues like winding contamination, voltage surges, current peaks and excessive vibration may drastically reduce operation time.

M&I Electric Brazil has a field team with over 15 years of experience in the market and a complete structure with tools and test instruments to identify problems and to provide on-site correction services.

» Preventive maintenance + electrical testing
» Installation, commissioning and startup of rotating electrical machines
» Vibration analysis and laser alignment
» Total rejuvenation
» Replacement of bearings/on-site maintenance of bearings
» On-site grinding of switches and collector rings
» Boroscope inspection
» Dynamic balancing of rotating sets
» Electromechanical expertise
» Equipment cleaning with dry ice (CO2)
» Emergency repairs
» Testing and inspection in AVRs (Automatic Voltage Regulators) and generator controllers

Workshop Service

Rotating electrical machines may present major electrical and mechanical problems, such as burning of the stator winding and wearing of the bearings. Certain corrective measures may only be conducted in repair workshops.

M&I Electric offers the necessary structure for electrical motors and generators recovery according to the following details:

Main characteristics:
» physical area of 2000m²
» 15-ton overhead crane
» vacuum impregnation (VPI)
» dynamic assays
» dynamic balancing of up to 2 tons
» 2 x 2 x 2 m heating chamber – 120°C in 1 hour Service scope:
» Service scope:
» total rejuvenation
» rewinding
» component manufacturing
» coil manufacturing
» bearing recovery
» dynamic balancing


Transformers are used for electrical power transmission from one circuit to another through a magnetically coupled circuit. Despite the static operation trait, certain problems like short-circuits between spirals and a high level of partial discharges are often observed.

M&I Electric relies on complete instrumentation for testing and validation of proper functioning of the transformer under maintenance.

» Oil and dry transformers;
» Internal and external cleaning;
» Transformer switchgear inspection;
» Power and control cables tightening inspection;
» Grounding connections inspection, internal and external;
» Fan function verification;
» Transformer cooling system verification;
» Electrical testing:

› Full isolation measurement (Megger);
› Coil Ohmic resistance (Ducter);
› Transformation relation (TTR) measurement;
› Overheating protection relay (PTR) function testing;
› Transformer power factor
› Transformer oil withdrawal for analysis;
› On-site transformer isolation oil treatment.