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© Copyright 2020 Zoeller
®
Co. All rights reserved.
Cutter Maintenance
1.
All power circuits must be disconnected and locked out before
any attempts are made at servicing.
The cutter and disc can be
removed and sharpened by grinding the cutting faces. Both 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 ring.
3. Thoroughly clean the 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 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 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 cutter from turning
while removing the bolt. Pull cutter from the shaft and remove the
spacer shims located behind the cutter.
5. Remove the six cap screws holding the disc and remove disc from
the pump.
6. The disc and cutter can be replaced with new service parts or
resurfaced by grinding. Resurfacing is accomplished by surface
grinding both disc and 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, 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 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 clear-
ance 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 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 six cap 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 posi-
tion. Add oil if required. Use insulating oil supplied by the factory.
FIGURE 6.
To remove cutter: Heat the center bolt to 350°F to
loosen Loctite
®
thread sealant.
Grind the Cutter and Disc seen here to a 32 microfinish.
Surfaces must be flat to within 0.001" T.I.R. Gap must be
between 0.007" and 0.012" on these parts.
