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7. Check resistance of windings.
If not within guidelines, return
pump to authorized factory service
center.
As the motors are oil filled, no
lubrication or other maintenance is
required. Pump should be checked every
quarter for corrosion and wear.
Pump Servicing
Replacing Grinder Parts:
Close gate valve at pump discharge and
turn off circuit breaker.
Remove pump from sump and unscrew
screws and remove cutter ring assembly.
Unscrew hex head cap screws and
remove volute case.
Radial cutter is now exposed.
If necessary to replace cutter, remove
screw, washer and radial cutter from
shaft. Tap radial cutter if necessary to
loosen. Unscrew impeller from shaft in
same manner.
Clean all parts thoroughly before
proceeding with assembly.
Replace case and cutter ring assembly.
Screw down with screws.
Plug pump into power and operate for a
few seconds only to ensure parts are not
rubbing.
Replacing Seal:
Drain the oil from the pump and remove
the volute and cutters.
Remove the impeller and seal rotating
elements by sliding the spring bellows
off the shaft.
Break the old stationary portion of the
seal to allow for removal.
Take the stationary portion of the new
seal and lube the rubber material with
®
Hydromatic
oil. Press the stationary
portion of the new seal into the seal/
bearing plate.
CAUTION: Do not reuse old seal
parts. Replace all parts with new.
Lube the rubber material on the carbon
seal assembly and press it on the shaft.
Place the spring bellows on the shaft as
removed.
Using a pressure gauge with a fill stem,
pressurize the motor housing no more
than 7 psig with dried air and check for
leaks for several minutes.
NOTE: It is normal to observe some
air bubbles in the seal area initially as
the seal seats. If bubbles do not stop
within a few seconds, the seal is either
not properly installed or is damaged.
Reassemble the cutter and volute as
outlined in the replacing grinder parts
section of this manual.
Refill motor housing with Hydromatic
oil. Fill the motor housing so that the
tops of the motor windings have been
covered, but leave an air gap to allow
for expansion of the oil.
Pump
Troubleshooting
Below is a list of troubles and their
probable causes:
No liquid delivered
1. Pump airbound.
2. Discharge head too high.
3. Pump or piping plugged.
4. Speed too low.
Insufficient liquid delivered
1. Discharge head too high.
2. Impeller or cutters partially
plugged or damaged.
3. Incorrect impeller diameter.
4. Speed too low.
Insufficient discharge pressure
1. Air or gases in liquid.
2. Impeller damaged.
3. Incorrect impeller diameter.
4. Speed too low.
Pump overloads motor
1. Specific gravity or viscosity of
liquid too high.
2. Speed too high.
3. Head lower than rating, pumping
too much liquid.
4. Pump clogged.
5. Defective bearings.
6. Defective impeller.
Pump is noisy
1. Defective bearings.
2. No axial clearance between
impeller and volute.
3. No diametral clearance between
radial cutter and cutter ring.
3
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