7
© Copyright 2020 Zoeller
®
Co. All rights reserved.
CUTTER MAINTENANCE
FIGURE 7
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. 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 0.007" and 0.012".
3. 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.
4. Remove the six cap screws holding the disc and remove disc from the pump.
5. 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.
6. 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 clearance must be between 0.007" and 0.012". Be sure pump is
in vertical position and all end play has been removed before measuring.
7. 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
0.007" and 0.012" to obtain efficient grinding when pump is put back in service.
8. 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.
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.
• After installing the pump into the basin, with adequate submergence, open the
discharge valve fully. Start the unit using manual controls. If flow is appreciably
less than rated performance, pump may be air locked. To expel trapped air, jog
the unit several times, using the manual controls.
• Have a qualified electrician take voltage and current measurements with the
pump running. Record these readings in the space provided in the
“Owner’s
Information”
section on page 1 of this manual for future reference.
ADJUSTMENT PROCEDURE
Pumps: No adjustments are required.
Floats: Refer to the system drawing or to the panel wiring schematic for the
desired location of each float switch setting. The off switch should
deactivate the pump before the water level drops to the mid-point of
the pump.
Valves: Discharge valves should be placed in the fully open position. Systems
should not be operated for extended periods of time
with the discharge
valves partially closed due to damaging the valve. Check for an anti-
siphon valve when used in a pressure sewer.
SHUTDOWN PROCEDURES
If a system is shutdown for more than six months, the following is recommended:
Pumps: If pit is to remain dry, then the pump can remain in the pit. Do not run
dry. If the pit is to remain wet, the pump should be removed and stored
as noted above.
Panels: The panel should have all openings sealed to prevent moisture and dust
from entering the enclosure. Prior to restarting system, the panel should
be inspected for presence of moisture and any loose connections.
Valves: Consult the valve/actuator supplier for information concerning
these systems components.
OPERATION,
continued
