5/29/13
Gulf Electroquip - GE 752 Drilling Motors, AC Generators, Motor Blowers, Bug Blowers, Spark Arrestors
Gulf Electroquip Ltd. • 425 North Wayside Drive • Houston TX 77020­7598
HOME
Why Remanufacture
Industries
Line Sheet
GEQ SALES & SERVICE
Phone 713­675­2525
Fax 713­675­6433
sales@gulfelectroquip.com
Products
Parts Counter
Customers
Facilities
Technical
Contacts
BRUSH/COMMUTATOR WEAR GUIDE
Commutator Appearance Guide
GULF ELECTROQUIP
POWER PRODUCTS
DRILLING MOTORS
In addition to the physical appearance of the surface of the commutator, the skin or patina (film) is of equal importance for the good running
of the carbon brushes. Each carbon brush builds a characteristic patina (film) which is affected by operating and ambient conditions. The
patina (film) consists mainly of copper oxides, graphite deposits and absorbed water, and its appearance is of importance for the
assessment of the running behavior of the commutation set. The following pictures are used by carbon brush manufacturers and users of
brushes as a guide to assist in judging the operation of carbon brushes.
Horizontal Traction, Mud Pump,
and Drawworks Motors
New GEQ 1150HP
Reman / Repair ­ GE, GEQ, EMD,
WEG, Yonge
Commutator Wear Guide
Full­Load Test / QC Docs
GEQ Parts Counter ­ Motors
TOP DRIVE MOTORS
Vertical Traction Motors
New GEQ 400HP
Reman / Repair Motors ­ GE, GEQ,
TSD11, WEG
Commutator Wear Guide
Full­Load Test / QC Docs
GEQ Parts Counter ­ Motors
LIGHT FILM: Indicates good brush
performance. Light load, low
humidity, brush grades with low
filming rates, or film reducing
contamination can cause lighter
color.
MEDIUM FILM: Is the ideal
commutator condition for maximum
brush and commutator life.
HEAVY FILM: Results from high
load, light humidity or heavy filming
rate grades. Colors not in the brown
tones indicate contamination
resulting in high friction and high
resistance.
STREAKING: Results from metal
transfer to the brush face. Light loads
and/or light spring pressure are the
most common causes.
Contamination can also be a
contributing factor.
THREADING: Is a further
development of the streaking
condition as the metal transferred
becomes work hardened and
machines into the commutator
surface. This condition can be
avoided by increased loads and
increased spring pressure.
GROOVING: May result from an
overly abrasive brush grade. The
more common cause is poor
electrical contact resulting in arcing
and the electrical machining of the
commutator surface. Increased
spring pressure reduces this
electrical wear.
COPPER DRAG: Develops as the
commutator surface becomes
overheated and softened. Vibration
or an abrasive grade causes the
copper to be pulled across the slots.
Increased spring pressure will
reduce commutator temperature.
BAR EDGE BURNING: Results from
poor commutation. Check 1.) that the
brush grade has adequate voltage
drop, 2.) that the brushes are
properly set on neutral, and 3.) that
the interpole strength is correct.
SLOT BAR MARKING: Results from
a fault in the armature windings. The
pattern relates to the number of
conductors per slot.
ROTARY TABLE MOTORS
Horizontal Traction Motors
New GEQ 400HP
Reman / Repair Motors ­ GE, GEQ,
TSD11
Full­Load Test / QC Docs
GEQ Parts Counter ­ Motors
GEQ MOTOR BLOWERS
For 400HP ­ 2000HP Hor. Traction,
Mud Pump and Drawworks Motors
Double Clean™
Double Clean™SS
Quiet Clean™
Quiet Clean™SS
RainMaster™
RainMaster™SS
ATEX Certified
ATEX Certified SS
For 400HP Vert. Top Drive Motors
Double Clean™ ­ Top Mount
Double Clean™ ­ Side Mount
For 400HP Hor. Rotary Table
Motors
Double Clean™ ­ Side Mount
GEQ Parts Counter ­ Blowers
GEQ BUG BLOWERS
Mighty Monsoon™
Mighty Monsoon™SS
GEQ Parts Counter ­ Mighty
Mini Monsoon™
Mini Monsoon™SS
GEQ Parts Counter ­ Mini
GEQ Sales
O&G AC GENERATORS
Reman / Repair ­ GE, Kato, ABB,
Baylor, CAT, EMD, Reliance,
Siemens, Toshiba, WEG
Full­Load Test / QC Docs
GEQ Parts Counter ­ AC Gen
AC & DC MOTORS 500HP+
Carbon Brush Performance Assessment
Notice the appearance of the brush sliding face. The following pictures show typical brush sliding faces. For easy identification, we suggest
you use the symbols S1, S3 etc. S1, S3 and S5 are satisfactory sliding faces, indicating that there are no mechanical or electrical problems.
Depending on the carbon material, the sliding surface appears dense or porous, and shiny, dull or matte. If there is dust in the circulating
air, fine hair­lining may occur, as shown in S5.
Large Motors ­ Industrial, Marine
and Commercial
Reman / Repair
www.gulfelectroquip.com/technical.php?technicalname=commutator
S1
Normal operation
1/3
5/29/13
Gulf Electroquip - GE 752 Drilling Motors, AC Generators, Motor Blowers, Bug Blowers, Spark Arrestors
Reman / Repair
GULF ELECTROQUIP
REMANUFACTURING,
REPAIR AND SERVICE
Facilities Tour
GEQ Product Line
Remanufacturing
Full­Load Test / QC Docs
Customers
GEQ Sales
S1
Dense, shining sliding face
S3
Normal operation
Slight porous sliding face
S5
Normal operation, slight dust influence
Fine hairlining
GULF ELECTROQUIP
PARTS COUNTER
S7
CAUSES:
Hairlining
Underload, influence of dust, oil, or
grease, weak spring pressure
S9
CAUSES:
Tracking with hairlining and grooves
Like S7, but stronger
S11
CAUSES:
Ghostmarks, difficult commutation
Commutation problems, e.g., false or
incorrect position of the neutral zone or
interpole
S13
CAUSES:
Burning edge of the leaving or trailing edge
Difficult commutation, heavy sparking,
interruption of contact due to out of round
of commutator or insufficient brush holder
spring pressure
S15
CAUSES:
Eroded brush face
Electrical overload, interruption of contact
S17
CAUSES:
Lamination of sliding face
Burned segments of the sliding face,
caused by a winding fault giving voltage
surge during commutation
S19
CAUSES:
Double facing here for a twin brush
Tilting of the brush in dual direction
machine
S21
CAUSES:
CALL 24/7 ­ 713­675­2525
parts@gulfelectroquip.com
www.gulfelectroquip.com/technical.php?technicalname=commutator
2/3
5/29/13
Gulf Electroquip - GE 752 Drilling Motors, AC Generators, Motor Blowers, Bug Blowers, Spark Arrestors
S21
CAUSES:
Copper nests
Pick up of copper particles, often following
copper drag
S23
CAUSES:
Broken edges
High raised lamination, commutator
seriously out of round, brush chatter by
low load and idle running
Got Wear?
Are you experiencing similar symptoms of brush or commutator damage? If possible, you may take a photo of the damage and e­mail us
the image. This will help us to diagnose the cause and prescribe the solution.
Information courtesy of Helwig Carbon Products www.helwigcp.com
©2013 Gulf Electroquip Ltd. Houston, TX
GULF ELECTROQUIP. DELIVERING HIGH­QUALITY PRODUCTS AND SERVICES FOR 57 YEARS
E­mail: sales@gulfelectroquip.com
DISCLAIMER: Product specifications and availability are subject to change without notice. Statements in this website or digital publication PDFs are not intended to create any warranty ­ expressed or implied.
Product trade names, marks or logos are the property of their respective owners. All photography and illustrations are copyrighted by Gulf Electroquip.
www.gulfelectroquip.com/technical.php?technicalname=commutator
3/3