Repair the right way

ELR has compiled the guide Recommended Working Methods for Repair of Rotating Electrical Equipment. The purpose of compiling the guide was to establish guidelines for all stages of rewinding and reassembling electrical equipment.

Do you have questions or comments about the guide?

Contact the ELR office: office@elr.se

The Recommended Work Practices for Repair of Rotating Electrical Equipment guide describes record keeping, testing, evaluations, and general guidelines for the repair of electrical motors and generators. It is not intended to replace customer or manufacturer specific instructions or specifications.

Excluded from the scope of this document are specific requirements, certification and inspection required for explosion-proof, dust-proof and other listed machines which are approved for hazardous environments as well as special or additional requirements for hermetically sealed motors, hydrogen-cooled motors, submersible motors, propulsion motors, or Class 1E motors for use in the nuclear industry.

The guide is divided into the following chapters:

Chapter 1: General

Intention
Extent
Identification
Cleaning
Connection lines
Connection points
Junction boxes
Cooling system
Exterior surface treatment
Packaging and transportation

Chapter 2: Mechanical Repair

Shoulders
Stock
Plain bearing
Lubrication
Stator housing & bearing seats
Rotor plates
Balancing
Slip rings
Commutators
Brush holder
Brushes
Brush positions on DC machines
Air gap measurement on DC machines
Accessories

Chapter 3: Rewinding

Inspection
Rewinding specification
Tearing out
Insulation system
Leader
Stator, rotor and armature windings
Field coils
Magnetizing and cage windings
Thermal protection and sensors
Forming and bonding of stator windings
Coil connections
Wedges
Impregnation of windings

Chapter 4: Testing

Security
Insulation test
Recommended winding tests
High voltage test
Idle test
Performance test
Instrument calibration

Bibliography

Standardization organizations and other sources