Service; General Information; Servicing Pumps With Explosion-Proof Motors; Pump Cleaning And Visual Inspection - Grundfos S Series Service Instructions Manual

8. Service

8.1 General information

DANGER
Electric shock
Death or serious personal injury
- Before starting work on the pump, make sure that
the mains switch has been locked in position 0.
Make sure that the power supply cannot be
accidentally switched on.
WARNING
Crushing of hands
Death or serious personal injury
- Make sure that all rotating parts have stopped
moving.
Except for replacement/dismantling of bearings, all
other service work must be carried out by Grundfos
or an authorised service workshop.
Service must be carried out by specially trained persons. Before
carrying out maintenance and service, it must be ensured that the
pump has been thoroughly flushed with clean water. Rinse the
pump parts with water after dismantling.
Before assembly:
• Clean and check all parts.
• Replace defective parts with new parts.
• Order the necessary service kits.
• Gaskets and O-rings should always be replaced when the
pump is overhauled.
During assembly:
• Lubricate and tighten screws and nuts to correct torque as
stated in section
6. Torques and

8.2 Servicing pumps with explosion-proof motors

Intervention in the flameproof enclosure of the pump is only
allowed for authorised Ex workshops.
Service not affecting the explosion protection of the pump is
allowed without violating Ex regulations.
Consequently, service persons who are not Ex authorised are
allowed to replace the following parts of explosion-proof pumps:
• pump housing
• impeller
• shaft seal.
All other service work must be carried out by an authorised Ex
workshop. Violation of this requirement will invalidate the Ex
classification of the pump.
lubricants.

8.3 Pump cleaning and visual inspection

A simple maintenance measure is to clean the pumps at regular
intervals. The pumps may be cleaned on site at the pumping
station when lifted up from the wet pit. Hose down the pump
externally using a high-pressure jet cleaner (maximum pressure
100 bar). Caked dirt on the motor must be removed to ensure
good heat conductivity. A mild detergent approved for disposal
into the sewage system may be used. The pumps may be
scrubbed, using a soft brush, if necessary.
Visual inspection of the pump should include search for cracks or
other external damage. Inspect the lifting bracket and lifting chain
for wear and corrosion. Inspect the pump cable for cracks or
lacerations in the sheath, kinks or other damage. Inspect visible
parts of the cable entry for cracks and for being firmly connected
to the motor top cover. Check all visible screws and tighten, if
necessary.
The air vent valve at the top of the cooling jacket may be removed
and cleaned, if necessary. Clean the vent hole before refitting the
valve after cleaning.

8.4 Annual maintenance

Pumps in normal operation should be inspected once a year. If
the pumped liquid is very muddy or sandy, check the pump at
shorter intervals.
The following points should be checked:
•
Power consumption
See section
5.1 Nameplate.
•
Oil level and oil condition
See section
8.5 Oil check and oil
•
Electrical measurements
See section
8.7 Electrical measurements.
•
Cable entry
Make sure that the cables are not sharply bent or pinched.
Replace the cables if necessary.
See section
9.1 Checking and replacing the
•
Sensors
Make sure that the sensors are working. Replace the sensors
if necessary.
See section
9.2 Replacing the protection sensors
•
Impeller clearance
Check the impeller clearance.
See section
8.6 Inspection and adjustment of impeller
clearance.
•
Pump parts
Check the pump housing, 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 an authorized service workshop.
On Ex pumps, the ball bearings must only be
replaced by an authorised Ex workshop.
•
O-rings and similar parts
During service / replacement, it must be ensured that the
grooves for O-rings and seal faces have been cleaned before
the new parts are fitted.
Do not reuse used rubber parts.
change.
cable.
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