Maintenance And Service; Replacement Of Cutter Head - Grundfos APG Serie Montage- Und Betriebsanleitung

9. Maintenance and service

Warning
Before starting work on the product, switch
off the power supply. Make sure that the
power supply cannot be accidentally
switched on.
Warning
Make sure that all rotating parts have
stopped moving.
Before carrying out maintenance and service, make
sure that the pump has been thoroughly flushed with
clean water. Rinse the pump parts in water after
dismantling.
Warning
When unscrewing the inspection screw of
the oil chamber, please note that pressure
may have built up in the chamber. Do not
remove the screw until the pressure has
been fully relieved.
Normally operating pumps should be inspected at
least once a year. If the pumped liquid is very muddy
or sandy, inspect the pump at shorter intervals.
When the pump is new or after replacement of the
shaft seals, check the oil level after one week of
operation.
For long and trouble-free operation of the pump the
following points should be checked regularly:
• Power consumption
• Oil level and oil condition
If the oil contains water, it becomes greyish white
like milk. Water in the oil may be due to a
defective shaft seal. The oil should be replaced
after 3000 hours of operation. Use Shell Ondina
X420 oil or a similar type of oil.
Used oil must be disposed of in
Note
accordance with local regulations.
Pump type
APG.50.11
APG.50.12
APG.50.18
APG.50.19
APG.50.29
APG.50.30
APG.50.33
APG.50.48
APG.50.65
APG.50.92
•
•
•

9.1 Replacement of cutter head

Remove the cutter head.
Fit the new cutter head as follows:
1. Knock guide pin (560) into cutter head (23).
2. Fit the cutter head with guide pin on impeller
3. Fit threaded pins (904) in suction cover (162).
4. Fit O-ring (412.01) in the suction cover, and
5. Knock the suction cover into pump housing (101)
6. Tighten all threaded pins (904) until they easily
7. Give all threaded pins a quarter of a turn.
8. Fasten the suction cover by means of screws
9. Fit cutting ring (50) to the suction cover. Fit and
Quantity of oil in
oil chamber [l]
0.70
0.70
1.00
1.00
1.00
1.00
1.00
1.90
1.90
1.90
Cable entry
Make sure that the cable entry is watertight and
that the cables are not bent sharply and/or
pinched.
Pump parts
Check the impeller, pump housing, neck ring, etc.
for possible wear. Replace defective parts.
Ball bearings
Check the shaft for noisy or heavy operation (turn
the shaft by hand). Replace defective ball
bearings. A general overhaul of the pump is
usually required in case of defective ball bearings
or poor motor function. This work must be carried
out by the manufacturer or a competent
workshop.
(230). Fit and tighten screw (900.01).
grease the cover.
until the suction cover bears against the impeller.
Check through the inlet port.
touch pump housing (101).
(914.01).
tighten screws (900.02).
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