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®
Co. All rights reserved.
Cutter Maintenance
To remove star cutter: Remove guard ring then heat the
center bolt to 350 °F to loosen Loctite® thread sealant.
Grind the Star Cutter and Disc seen here to a 32 microfinish.
Surfaces must be flat to within 0.001” T.I.R. Gap must be between
0.004” and 0.008” on these parts.
1.
All power circuits must be disconnected and locked
out before any attempts are made at servicing.
The star
cutter and disc can be removed and sharpened by grinding
the cutting faces. Both star cutter and disc must be removed
from the pump. Removal of these parts can be accomplished
in the field by removing pump from the sump and positioning
horizontally to access the intake of the pump. If seals or
other repairs are required, the pump must be totally removed
and serviced in a shop by a qualified pump technician or
authorized service center.
2. Remove the three countersunk screws on the plastic guard
ring and remove the ring.
3. Thoroughly clean the star cutter and disc assembly. Tilt pump
back to the vertical position to make certain the end play has
been removed. Check and record the clearance between the
star cutter and disc with a feeler gage. The correct running
clearance is between 0.004" and 0.008".
4. With pump in horizontal position, heat the hex head bolt in
the center of the star cutter with a propane torch. The bolt
must be heated to 350 °F to soften the thread lock sealer
on the bolt for ease of removal. Remove the bolt by turning
in a counterclockwise rotation. It will be necessary to use
a wood block to prevent the star cutter from turning while
removing the bolt. Pull star cutter from the shaft and remove
the spacer shims located behind the star cutter.
5. Remove the three cap screws holding the disc and remove
disc from the pump.
6. The disc and star cutter can be replaced with new service
parts or resurfaced by grinding. Resurfacing is accomplished
by surface grinding both disc and star cutter to a 32 micro
finish. Do not attempt grinding in the field. Send parts to
a qualified machine shop or return to the factory for repair.
The disc, star cutter and shims are a matched set. Keep
parts together. Measure disc before and after resurfacing
with micrometer and record measurements.
7. After resurfacing, the disc and star cutter must be flat within
0.001". If the disc has been surface ground, it will be necessary
to remove shims to compensate for the material removed
from the disc. As a starting point, remove shims of the same
thickness as the amount machined from the cutter disc (step
6 above). Final running clearance must be between 0.004”
and 0.008”. Be sure pump is in vertical position and all end
play has been removed before measuring.
8. Clean bottom of pump where disc is located and replace
disc and retainer screws. Torque to 63-67 in-lbs. Replace
star cutter with the correct shims. Install washer and torque
hex head bolt to 71-75 in.-lbs. apply Loctite 262 thread-lock
sealant or equal to bolt threads prior to insertion. Check
running clearance with pump in vertical position to remove
end play. Clearance must be between 0.004" and 0.008" to
obtain efficient grinding when pump is put back in service.
9. Replace plastic guard ring and its three screws.
10. Check the oil in the motor housing before reinstalling. Contact
the factory if the oil has a milky appearance or burnt smell.
The level should be even with the fill plug when pump is in
the upright position. Add oil if required. Use insulating oil
supplied by the factory.
FIGURE 7.
(Model 7011 components shown)
