Electrical Connection; Stroke Length Setting; Start-Up; Maintenance - Grundfos DMM 4 Instrucciones De Instalación Y Funcionamiento

4.6 Electrical connection

• The electrical connection of the pump should be
carried out by qualified persons in accordance
with local regulations.
• For electrical data of the pump, see sections 2.2
and 3.2.
• Connect the motor to a motor starter which should
be set according to the motor data.

5. Stroke length setting

Note: The pump must be operating when the stroke
length is set.
Set the stroke length in the following way:
1. Loosen the locking screw in the middle (counter-
clockwise).
2. Set the stroke length to the desired value, ac-
cording to the performance table on the pump or
the performance curves at the end of these in-
structions.
3. Retighten the locking screw while the stroke
length setting is maintained.

6. Start-up

Before beginning the start-up procedure, make sure
that the pump has been installed correctly and the
electricity supply has been switched on.
Follow this procedure when starting the pump:
1. Gear oil.
Fill the pump with the gear oil supplied.
2. Starting the motor.
Check that the direction of rotation of the motor is
correct. The correct direction is indicated by an
arrow on the fan cover.
3. Priming.
Set the pump to maximum stroke frequency (for
further details, see section 5. Stroke length set-
ting) and allow the pump to operate without coun-
ter-pressure (if possible).
If self-priming is not successful:
1. Stop the pump.
2. Remove the discharge valve and pour clean
water or a harmless chemical into the dosing
head.
3. Reinstall the discharge valve and allow the
pump to self-prime.
4. Setting.
When the pump is primed and operates at the
correct counter-pressure, set the stroke length,
see section 5. Stroke length setting.
If the pump does not work as intended, it is advisable
to refer to section 9. Fault finding chart.
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7. Maintenance

The dosing pump is maintenance-free. However, it is
recommended to renew the gear oil of the pump after
approx. 5000 operating hours.
Recommended oil quality: Viscosity class
ISO-VT 100 (corresponding to SAE 30).

7.1 Service kits

A service kit is available for all GRUNDFOS dosing
pumps. The kit consists of all wearing parts for the
individual pump type.
The service kit includes:
• Diaphragm,
• O-rings,
• Gaskets,
• Valve balls,
• Valve seats.
See the product numbers at the end of these instruc-
tions.

7.2 Replacement of diaphragm

Replace the pump diaphragm in the following way:
1. Stop the pump.
2. Remove the dosing head.
3. Remove the fan cover from the motor.
4. Turn the fan until the diaphragm is in the outer
position.
5. Unscrew the diaphragm (counter-clockwise).
6. Grease the diaphragm rod.
Recommended lubricants:
Molycote BR 2 Plus.
OKS 400.
7. Check that the seal washer behind the diaphragm
rests in the groove of the diaphragm rod.
8. Screw on the new diaphragm (clockwise).
9. Mount the dosing head and the fan cover.

8. Service

Note: If a pump has been used for a liquid which is
injurious to health or toxic, the pump will be classi-
fied as contaminated.
If GRUNDFOS is requested to service the pump, it
must be ensured that the pump is free from sub-
stances that can be injurious to health or toxic. If the
pump has been used for such substances, the pump
must be cleaned before it is returned.
If proper cleaning is not possible, all relevant infor-
mation about the chemical must be provided.
If the above is not fulfilled, GRUNDFOS can refuse
to accept the pump for service. Possible costs of re-
turning the pump are paid by the customer.