Xylem e-NSCS: 6 Maintenance

en - Translation of the original instructions

Cause

Remedy

6 Maintenance

There are foreign objects (solids or

Contact the Sales and Service

Precautions

fibrous substances) inside the

Department.

pump which have jammed the im-

Electrical Hazard:

peller.

Disconnect and lock out electrical power before installing or

The pump is overloaded because

Check the actual power require-

servicing the unit.

it is pumping liquid that is too

ments based on the characteris-

dense and viscous.

tics of the pumped liquid and then

WARNING:

contact the Sales and Service

• Maintenance and service must be performed by skilled

Department.

and qualified personnel only.

• Observe accident prevention regulations in force.

The pump runs but delivers too little or no liquid.

• Use suitable equipment and protection.

• Make sure that the drained liquid does not cause dam-

Cause Remedy

age or injuries.

The pump is clogged. Contact the Sales and Service Department.

6.1 Service

If the user wishes to schedule regular maintenance deadlines, they are

The troubleshooting instructions in the tables below are for installers

dependent on the type of pumped liquid and on the operating condi-

only.

tions of the pump.

Contact the local sales and service representative for any requests or

7.2 The main switch is on, but the electric

information regarding routine maintenance or service.

pump does not start

Extraordinary maintenance may be necessary to clean the liquid end

and/or replace worn parts.

Cause Remedy

Motor bearings

There is no power supply. • Restore the power supply.

• Make sure all electrical connec-

After approximately five years, the grease in the motor bearings is so

tions to the power supply are in-

aged that a replacement of the bearings is recommended. The bear-

tact.

ings must be replaced after 25000 operating hours or according to the

motor supplier maintenance instructions, whichever is shorter.

The thermal protector incorpo-

Wait until the pump has cooled down.

rated in the pump (if any) has

The thermal protector will automati-

Motor with regreasable bearings

tripped.

cally reset.

Follow motor supplier maintenance instructions.

The thermal relay or motor

Reset the thermal protection.

protector in the electric control

6.2 Torque values

panel has tripped.

For information about torque values, pump data see Figure 28 .

The protective device against

Check the:

6.3 Inspection checklist

dry running has tripped.

• liquid level in the tank, or the

mains pressure

Check the coupling

Check the flexible elements of the

• protective device and its con-

coupling. Replace the relevant

necting cables

parts if there is any sign of wear

and check the alignment.

The fuses for the pump or

Replace the fuses.

auxiliary circuits are blown.

Check the mechanical seal Check for leakage of the mechani-

cal seal. Replace the mechanical

seal if leakage is found.

7.3 The electric pump starts, but the thermal

protector trips or the fuses blow immediately

Checking the bearing seals Check correct seating of axial seal

rings mounted on the shaft. Only

after

gentle contact of the sealing lip

shall be established.

Cause

Remedy

The power supply cable is

Check the cable and replace as nec-

6.4 Disassemble and replace the pump parts

damaged.

essary.

For more information about spare parts and assembly and disassem-

The thermal protection or fuses

Check the components and replace

bly of the pump see Figure 1 , Figure 2 , Figure 3 .

are not suited for the motor

as necessary.

See the Repair and Assembly Instructions which are available for

current.

download from our homepage.

The electric motor is short cir-

Check the components and replace

cuit.

as necessary.

7 Troubleshooting

The motor overloads. Check the operating conditions of the

pump and reset the protection.

7.1 Troubleshooting for users

7.4 The electric pump starts, but the thermal

The main switch is on, but the electric pump does not start.

protector trips or the fuses blow a short time

Cause

Remedy

after

The thermal protector incorpo-

Wait until the pump has cooled

rated in the pump (if any) has

down. The thermal protector will au-

Cause

Remedy

tripped.

tomatically reset.

The electrical panel is situated in an

Protect the electrical panel from

The protective device against

Check the liquid level in the tank, or

excessively heated area or is ex-

heat source and direct sunlight.

dry running has tripped.

the mains pressure.

posed to direct sunlight.

The power supply voltage is not

Check the operating conditions

The electric pump starts, but the thermal protection trips a varying time

within the working limits of the mo-

of the motor.

after.

tor.

18 e-nscs Installation, Operation, and Maintenance Manual

en - Translation of the original instructions

Cause Remedy

7.9 The electric pump stops, and then rotates

A power phase is missing. Check the

in the wrong direction

• power supply

• electrical connection

Cause Remedy

There is a leakage in one or both of the follow-

Repair or replace the

ing components:

faulty component.

7.5 The electric pump starts, but the thermal

• The suction pipe

protector trips a varying time after

• The foot valve or the check valve

Cause Remedy

There is air in the suction pipe. Bleed the air.

There are foreign objects (sol-

Contact the local sales and service

ids or fibrous substances) in-

representative.

7.10 The pump starts up too frequently

side the pump which have jam-

med the impeller.

Cause Remedy

The pumps delivery rate is

Partially close the on-off valve down

There is a leakage in one or both of the fol-

Repair or replace the

higher than the limits specified

stream until the delivery rate is equal

lowing components:

faulty component.

on the data plate.

or less than the limits specified on

• The suction pipe

the data plate.

• The foot valve or the check valve

The pump is overloaded be-

Check the actual power requirements

There is a ruptured membrane or no air

See the relevant instruc-

cause it is pumping liquid that

based on the characteristics of the

pre-charge in the pressure tank.

tions in the pressure

is too dense and viscous.

pumped liquid and replace the motor

tank manual.

accordingly.

The motor bearings are worn. Contact the local sales and service

representative.

7.11 The pump vibrates and generates too

much noise

7.6 The electric pump starts, but the system's

Cause Remedy

general protection is activated

Pump cavitation Reduce the required flow rate by partially closing

the on-off valve downstream from the pump. If the

Cause

Remedy

problem persists check the operating conditions of

A short circuit in the electrical system. Check the electrical system.

the pump (for example height difference, flow re-

sistance, liquid temperature).

7.7 The electric pump starts, but the system's

The motor bear-

Contact the local sales and service representa-

ings are worn.

tive.

residual current device (RCD) is activated

There are foreign

Contact the local sales and service representa-

Cause

Remedy

objects inside the

tive.

pump.

There is an ground

Check the insulation of the electrical system

(earth) leakage.

components.

For any other situation, refer to the local sales and service representa-

tive.

7.8 The pump runs but delivers too little or no

liquid

Cause

Remedy

There is air inside the

• Bleed the air

pump or the piping.

The pump is not correctly

Stop the pump and repeat the prime pro-

primed.

cedure.

If the problem continues:

• Check that the mechanical seal is

not leaking.

• Check the suction pipe for perfect

tightness.

• Replace any valves that are leaking.

The throttling on the deliv-

Open the valve.

ery side is too extensive.

Valves are locked in

Disassemble and clean the valves.

closed or partially closed

position.

The pump is clogged. Contact the local sales and service repre-

sentative.

The piping is clogged. Check and clean the pipes.

The rotation direction of

Change the position of two of the phases

the impeller is wrong .

on the terminal board of the motor or in

the electric control panel.

The suction lift is too high

Check the operating conditions of the

or the flow resistance in

pump. If necessary, do the following:

the suction pipes is too

• Decrease the suction lift

great.

• Increase the diameter of the suction

pipe

e-nscs Installation, Operation, and Maintenance Manual 19