Rockwell Automation 1325L DC Motors, Frames C210ATZ - C440ATZ - Manual (Page 20)

20 DC Motors
4. Rotate the rocker ring by hand 90 degrees to replace brushes
located in the 12 and 6 o'clock position.
5. Return rocker to original position and change brushes in the 3 and
9 o'clock position.
6. Re-align the neutral setting mark on the rocker ring in line with
the mark on the bracket boss.
7. Tighten the four hex head cap bolts which hold the rocker ring to
the bracket.
8. Fit the face of new brushes to the contour of the commutator with
sandpaper only, no emery abrasive. Keep brush lead (pigtail)
connections tight. Replacement brushes should have sleeved
pigtails.
9. Install the hand hole covers to each side of the commutator
bracket.
Commutator
A commutator in good condition is clean and smooth with a medium
polish and a light brown color. Keep clean by occasionally wiping
with a canvas pad. Use no lubricant or emery abrasive. If a
commutator becomes rough, it needs to be resurfaced. Roughness can
be easily detected with the machine running by resting a pencil-like
rod of insulating material (dry wood) on one of the brushes. In mild
cases, a commutator dressing stone can be used. Very rough or out of
round commutators require turning in a lathe. In every case, maintain
concentricity and remove the minimum material required for proper
cleanup. Undercut the mica approximately l/16” and polish. Adjust
brush holders for approximately 3/32” clearance to commutator.
The new diameter and the minimum diameter of the commutator for
the various frames sizes are as follows:
The commutator should be replaced if the final diameter would have
to be turned down to a value less than minimum limits.
!
ATTENTION: To guard against personal injury or death,
ensure that all power to the motor has been removed and
the motor shaft is stationary. Brushes must not be touched
or replaced while motor is energized or rotating.
Frame
New Diameter Minimum Diameter
Inches Millimeters Inches Millimeters
C210ATZ 5.03 127.8 4.59 116.6
C250ATZ 5.78 146.8 5.34 135.6
C280ATZ 6.53 165.9 6.09 154.7
C320ATZ 7.53 191.3 7.09 180.1
C360ATZ 8.70 221.0 8.26 209.8
C400ATZ 9.55 242.6 9.06 230.0
C440ATZ 10.78 274.0 10.31 262.0