Jung Pumpen MultiFree UAK 25/2 AW /3 Instructions De Service page 6

English
When using a chain to lift the pump,
please observe the relevant national
regulations regarding accident pre-
vention. Lifting gear must be checked regularly
by an expert in accordance with the legal regu-
lations.
Motors in the UFK range conform to
the "flameproof enclosures" ignition
protection category. Maintenance
works that affect the explosion protection may
only be carried out by authorised specialists or
by the manufacturer. When carrying out re-
pairs, all areas next to flameproof gaps must be
checked for damages and, if necessary, re-
placed by genuine parts.
Oil check
The drain plug is labelled "Öl". In order to check
the mechanical seal, the oil, including any resi-
due, must be drained from the oil reservoir and
collected in a clean measuring container.
• If the oil is contaminated with water (milky),
an oil change must be carried out. Check
again after a further 300 operating hours,
but at the very latest after 6 months!
• However, if the oil is contaminated with
both water and pollutants, then not only
the oil must be replaced, but the mechani-
cal seal as well.
For monitoring the oil reservoir, it is also pos-
sible to retrofit the electrode of our "DKG" or
DKG-Ex" seal leak control device in place of the
"DKG" sealing screw.
Changing the oil
To ensure operational liability, the first oil
change should be carried out after 300 operat-
ing hours, with further oil changes carried out
after every 1000 operating hours.
If the number of operating hours is very low,
an oil change should still be carried out at least
once a year.
If wastewater with strongly abrasive constitu-
ents is being pumped, the oil changes should
be carried out at correspondingly shorter inter-
vals.
Use HLP hydraulic mineral oil, viscosity class 22
to 46, e.g. Mobil DTE 22, DTE 24, DTE 25, to re-
place the oil in the oil reservoir.
The quantity of oil required is 1000 cm³, except
for CW2 pumps, which must be filled with 1700
cm³.
The oil reservoir may only be filled with the
specified quantity of oil. Overfilling will result
in the pump being rendered inoperable.
6 6
Cleaning
To clean the open centrifugal impeller and the
volute casing, simply remove the 4 hexagonal
M 10 x 20 screws and lift the motor unit off the
ring housing.
Worn impellers can have sharp edges.
ATTENTION!
If the wrong screws are un-
screwed, the oil will run out of the oil reservoir.
Tightening torque M for A2 screw materials
A
for M 6 M = 8 Nm
A
for M 8 M = 20 Nm
A
for M 10 M = 40 Nm
A
for M 12 M = 70 Nm
A
for M 16 M = 160 Nm
A
Checking the pump unit
The housing screws for the pump, and the con-
necting and fixing screws of the installation
must be checked to ensure they are fixed se-
curely. They should be tightened if necessary.
If the pump performance decreases, or if in-
creasingly loud noises can be heard during
operation, the open centrifugal impeller must
be checked for wear by an expert and replaced
if necessary.
Tightening
Gap dimen- Pump
torque of the
sion X type
impeller screw
2 mm AW 65 Nm
2 mm BW1 65 Nm
2 mm CW1 65 Nm
3 mm CW2 160 Nm
Replacing the impeller
Worn impellers can have sharp edges.
1. Remove the 4 hexagonal screws and lift the
motor unit off the ring housing.
2. Block the impeller to prevent it from turning.
3. Loosen the central impeller screw located in
the impeller hub.
4. Loosen the impeller by knocking it gently
with a hammer and then slide it off the shaft.
5. Clean all the parts of the impeller mounting.
6. Grease the shaft cover on the inside. ATTEN-
TION! Do not use grease containing graphite,
(e.g. "Molykote").
7. Fix all the parts of the impeller mounting in
place and tighten the impeller screw until it is
"hand tight".
8. Slide the new impeller over the preassem-
bled impeller mounting onto the shaft.
9. Set the gap dimension x and then tighten the
impeller screw securely.
10. Mount the motor unit on the ring housing;
the cable entry point is opposite the discharge
branch.
What to do in the
event of any problems
Pump does not work
• Check mains current (do not use a pin
gauge)
• Fuse faulty = may be too weak (please refer
to Electrical Connection)
• Mains supply cable damaged = repair to be
carried out by manufacturer only
Pump runs but does not pump
• Empty pressure pipe or hose to allow the
non-return valve to open and let the air
escape from the ring housing.
• Ventilate the pump housing by unscrewing
the "Luft" (air) sealing screw.
The impeller is blocked
• Solids and fibrous matter have become
lodged in the ring housing (please refer to
Maintenance)
Decreased pumping performance
• The impeller is blocked (please refer to
maintenance)
• The impeller is worn out = replace it
• Wrong direction of rotation = change 2
phases of the power supply