Reassembly - Pentair HYDROMATIC SKHD150 Installation Et Manuel De L'opérateur

Maintenance
8. For 3ø pumps, remove the power cord assembly (27)
by cutting the butt connections and removing the
power cord from the pump.
9. Twist the three leads of one end of the power cord
together. Then at the other end, with an ohmmeter,
check any two leads. Also check the third lead with
either of the first two. If a zero reading is indicated
for any wire, the wire is broken and a new power
cord assembly must be installed.
Seal Housing:
The pump is equipped with two mechanical seals
mounted in tandem. The lower seal (20) and the upper
seal (8) consist of a ceramic stationary seat and a carbon
rotating ring.
As noted, if water is detected in the motor housing,
inspect the power cord connection, pipe plug
connections, O-rings, the motor housing itself, and the
two mechanical seals.
To check the seals, remove the seal housing pipe plug
(11) and pour the oil out into a clean glass container.
Look for the milky color as noted previously.
If the oil is clear, the lower seal is still good. If this seal
is damaged, water will seep in and continue to stain the
oil, changing it gradually from clear to a milky white.
Then the lower seal and oil must be replaced.
Except for very rare instances, the motor will continue to
be protected by the upper mechanical seal. If seal probe
is used the pump will not shut off when water in the oil
is sensed. However, if connected to a control panel, an
alarm or light will be activated. The panel alarm will
show failure.
Lower Seal:
If water is found in the seal chamber, the lower seal must
be replaced. Separate the volute by removing the screws
(7) holding the volute case (10) to the upper volute.
Insert a large screwdriver in the slotted pump shaft
and strike the impeller sharply with a plastic or rubber
headed hammer. The impeller should spin free. The
impeller holds the rotation carbon ring of the lower
mechanical seal against the stationary ceramic seat by
compressing a stainless steel spring.
When the impeller is removed, the spring will relax,
allowing the carbon ring to be removed. There is a
rubber sleeve (bellows) inside the spring which grips the
pump shaft. This often restricts the spring and must be
pried or pulled loose.
With the carbon ring, spring, and rubber sleeve removed,
wedge the ceramic seat out of the housing. Be sure not
to scratch or mar the pump shaft.
Upper Seal:
1. To remove and replace the upper mechanical seal
(8), the volute base (10), impeller (16), and lower
mechanical seal (20) must be removed first. Drain
the seal oil from the housing by removing pipe
plug (11).
2. The rotating carbon ring and stainless steel spring are
held in place by a snap ring (21) and washer (15).
Remove these items.
3. Remove the four hex head stator bolts and lift the
motor (5) from the seal plate (14). A screwdriver can
be inserted under the stator shell in order to remove
the stator.
4. Tap the end of the shaft with a plastic hammer. This
will push the rotating half of the mechanical seal
(20) from the shaft and also push the lower bearing
from the seal plate (14). Now remove the shaft, rotor,
and bearing assembly from the seal plate.
5. If water is found in the oil, both the rotating and
stationary halves of the mechanical seal (20) must be
replaced. Remove the stationary seal half by inserting
a screwdriver into seal plate (14) from the top and
tapping lightly with a hammer.
6. Turn the bearing by hand and if it feels rough when
turned or looks rusted, it should be replaced. Use a
bearing puller to remove the bearing.

Reassembly

1. Thoroughly clean the seal plate, particularly the
seal and bearing pockets. All sand and dirt must
be removed.
2. If the stationary seal half (8) was removed, wet the
seal components with clean oil. Use a plastic pusher
to press the stationary seal into the housing. Make
sure the rubber ring goes in first. Do not use any
sharp objects that may damage the seal.
3. When installing a replacement bearing, press only
on the inner face and make sure the bearing is flush
against the snap ring. If a press is not available, the
bearing can be tapped onto the shaft using a sleeve
that bears only on the inner face. Pressing on the
outer face will ruin the bearing.
4. Push the shaft, rotor and ball bearing assembly into
the seal plate, being careful not to chip the ceramic
of the stationary seal half.
5. Replace the motor (5) if it is visibly burned or if the
ground resistance test or the winding resistance test
has failed. Note that the replacement stator must be
of the same manufacture as the existing rotor, or vice
versa. Replace the four stator bolts.
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