Level Switch & General Wiring; Maintenance, Inspection And Overhaul; Maintenance; Inspection - VARISCO K Serie Instrucciones Para El Uso Y La Manutención

7.6 LEVEL SWITCH & GENERAL WIRING
7.6.1 Level switch & general wiring for general drainage purposes to operate one
pump automatically (Fig. 10).
8.

MAINTENANCE, INSPECTION AND OVERHAUL

8.1

MAINTENANCE

Since the life of the pump depends largely on the operating conditions, daily inspection and
periodic servicing are strongly recommended to guarantee maximum product lifetime.
8.1.1 Current and Voltage. Check the pump current and voltage. If the ammeter reading
exceeds the rated value, or is far lower than rated value, there is a problem with the
pump. Voltage should be stable within (plus minus) 10% of the rated value throughout
the operational period.
8.1.2 Vibration. Check that the pump is operating smoothly and without vibration
8.1.3 Discharge Pressure and Flow Rate. Check the discharge pressure and flow rate (If
flow meter is provided) at least once a month. Declining performance can be indicative
of the need for overhaul. Regardless of performance the pressure and flow rate should
be stable and rapidly changing output or pressure is indicative of system problems on
the suction or delivery side.
8.1.4 Insulation Resistance. Check the insulation resistance of the motor at least monthly.
If the value of the insulation resistance has declined sharply from the previous reading
this is indicative of impending insulation failure and the pump should be scheduled
for service even though the insulation resistance may still be over 10 Mega-Ohm.
8.2

INSPECTION

Under normal operation the pump should be removed from the pit and inspected once per
year. Under severe operating conditions where sand, fibrous material and solids are present
this should be done once per month.
The standard inspection procedure is summarized below.
8.2.1 Pump Removal
· Loosen the bolts/nuts of the discharge piping so that the seal is broken.
· Hook the lifting chain on the motor driven hoist or chain-block through the pump
lifting eye and support the load of the pump.
· Remove the bolts/nuts of the discharge piping and lift the pump out of the well with
the hoist.
8.2.2 Inspection Procedure
8.2.2.1 Mechanical Seal. Check the resistance of mechanical seal sensor with Multi-Tester
as shown overleaf. Do not use a Mega Tester this will damage the control circuit (Fig.
9).
8.2.2.2 Oil Replacement. After checking the resistance of seal sensor, replace the oil in the
oil chamber. First unscrew the oil inlet plug and tilt the pump towards the horizontal
position with the plug hole facing downwards in order to drain the oil.
If the drained oil is contaminated or opaque, this is indicative of impending mechanical
seal failure & the mechanical seal should be replaced. Replace the oil with fresh oil
injected through inlet oil plug hole (Lubrication Oil ISO VG 32 Mobil DTE 24 Turbine
Oil 90 or equivalent).
8.2.2.3 Inspect Impeller and Wear Plate. Check the impeller and wear plate for excessive
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K SERIES SUBMERSIBLE PUMPS