Maintenance 5
Checking motor stator
remove plug (21) from top of housing (19) and pour oil
into a clean glass container. There are approximately
two quarts of oil in the motor housing. If oil is clear, it
will indicate motor is not burned and there has been no
water leak into the motor. If oil is black, it will indicate
a burned stator. If oil is cloudy, it will indicate water in
motor oil, so all seals should be replaced.
remove bolts (17) to separate volute case (12) from
motor housing. remove o-ring (18) and seal plate (11)
from motor housing. remove bolts to separate motor-
stator from rotor. If stator is visibly burned, it must be
replaced. If stator is not burned but the oil shows signs of
water, stator can be checked with the ohmmeter to see if
it can be used.
Ground check
Set ohmmeter scale to r X 1 scale and check meter
by putting both meter leads together and adjusting the
needle knob until meter reads zero. If meter cannot be
adjusted to zero, the batteries in meter must be replaced.
NOTICE: always reset meter to zero [0] when going to a
new scale before making any measurements.
If wire is oK, meter needle will go to near zero and stay
there. If meter needle does not move, the wire has an
open and the wire must be repaired or replaced.
connect one meter lead to one blade terminal of stator
and touch other meter lead to motor stator housing (4). If
the resistance to the ground is less than 500,000 ohms,
stator must be dried out before retesting. To dry out,
place pump in 220 degree oven for four hours. recheck
after motor cools.
If motor is thoroughly dry, needle of ohmmeter will not
move on the ground check. This indicates a reading of
50 megohms or higher. When making the ground check,
if the needle goes to zero, the motor has a wire touching
the stator shell at some place and the stator will have to
be replaced.
NOTICE: If motor shows a satisfactory ground check then
the winding resistance must be checked.
Winding resistance test
Use ohmmeter with scale set to r X 1 scale. on this
scale, meter reads directly in ohms. recheck to zero [0]
before making a reading on the winding.
NOTICE: If water is found in motor, seal should
be replaced.
Replacing seal
Hold rotor. on 3 phase motors only, remove the impeller
screw and impeller washer. Unscrew impeller (13). Tap
on end of shaft with plastic or rubber hammer. This will
push the rotating seal (10) from shaft and also push
lower bearing from seal plate. clean seal plate (11) and
motor housing (19) thoroughly. all sand and dirt must
be removed. remove stationary ceramic seat of seal (10)
from seal plate. Push new ceramic seat into seal plate.
Use o-ring Lube on rubber ring. replace rotor in seal
plate (11). Use care in putting shaft through ceramic seat
to be sure it is not chipped. Inspect seal after shaft is in
place. If seal has been chipped it must be replaced. do
not replace rotating part of seal until the balance of the
pump is assembled.
Bearings
When the pump rotor has been removed, check bearings
before replacing. If bearings are rusted or rough when
turned, they should be replaced. When installing a
replacement bearing, press only on the inner face. If a
press is not available, bearings can be tapped on, using a
sleeve that bears only on the inner face.
NOTICE: Never pound on the outer face of the bearing
as this will cause bearing damage.
Reassembly
1. Push the new rotor shaft and ball bearing assembly
into the seal plate. (Note that the replacement rotor
must be of the same manufacture as the existing
stator, or vice versa.) reassemble the motor (4) to
the seal plate (11) with the four long cap screws. Be
sure to tighten down the bolts evenly and firmly to
prevent cocking of the stator. an uneven assembly
can cause the rotor to rub the motor causing the
motor to short.
2. Press the new ceramic seal (10) in place with
the rubber ring facing the impeller. This should
have a thin oil (dielectric, same as in motor
housing) coating.
NOTICE: ceramic must be kept clean. any dirt will
cause seal failure.
3. Start the impeller (13) on the shaft one to two turns;
then, add a drop of
2
Loctite® #243 to the impeller
threads and screw the impeller hand tight. The
impeller will force the ceramic seal into position.
The shaft should be free of dirt, grease, etc., or the
Loctite® will not hold as designed. replace impeller
washer and impeller screw to the shaft on three
phase models.
2
Henkel corporation, Germany
NOTICE: Loctite® overrun onto the seal or bearing
will result in shaft seizure.
Summary of Contents for HYDROMATIC SK60 Series
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