Article

Introducing IEEE 2455: DC Repair Standard

IEEE Recommended Practice for the Repair and Maintenance of Direct Current Electric Machines

September 2025
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Chuck Yung
EASA Senior Technical Support Specialist

There is now a much-needed DC repair standard, created through the participation of EASA members and industry motor users. The scope, as written in the document, states: “This document covers general recommendations for the repair of DC electric motors and includes guidelines for both the user and the repair facility ... . This standard covers reconditioning, repair and rewind of horizontal and vertical wound-field direct current motors and generators. It applies to all ratings above 0.75 kW (1 hp).”

The standard was created by a group of like-minded industry professionals who recognized the need for a best practice guide specific to DC machines. The working group accomplished the creation of 2455 in fewer than three years, from project authorization request approval to final publication. This document was modeled after IEEE 1068, a widely used electric motor repair standard.

NOTE: Interested in a copy of IEEE 2455? Visit http://standards.ieee.org/ieee/2455/7186.

The working group participants were:

Charles Yung, Chair Chris Heron, Vice Chair* Mario Lanaro, Secretary*
Paul Anderson* Blake Bailey* Jim Cannon* Roy Douglas Matt Florczykowski* Travis Griffith Richard A. Holub Brian Honeycutt Carick Howard* Bruce Lyle* John Malinowski*	Noboru Morita Craig Mouton Kelly Murphy Blake A. Parker* Guy Puma* Roland Roberge Matt Rutherford* Jim Williams* Mark Zawadski

*Denotes EASA member

The working group covered everything from the receipt of the machine, to inspection and testing, to all aspects of repair including rewinding. Beginning with “Diagnostics in user’s plant,” the document recommends specific information gathering by the motor owner/end user to provide as much information as practical to the repair facility.

Incoming tests for the repair facility are described in detail, with many tests (e.g., voltage drop test) being very familiar to EASA service centers. Nearly a dozen figures will be familiar to EASA members because they were originally published in EASA documents.

The standard includes specific rewinding tips for fields and armature, as well as assembly and final test recommendations. IEEE 2455 also includes annexes for an Evaluation and Repair form, turn and undercut guidelines, an explanation of commutation, Commutator Condition Guide, sleeve bearing clearance, ventilation and cooling, post-assembly electrical adjustments and bearing currents in DC machines.