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ENGLISH
into the 3 markings with the ø 8 sym-
bols. Deburr the drill-holes. Re-attach
the cover with the round sealing ring
and the foot strainer or base feet.
MAINTENANCE
We recommend that you service the
equipment in accordance with EN
12056-4.
To ensure continued reliability of ser-
vice, we recommend that you take out a
service contract.
Before carrying out any works:
disconnect the pump and the
controls from the mains and
take steps to ensure that no one else
can reconnect them to the power sup-
ply.
Check the rubber hose for me-
chanical or chemical damage.
A damaged or kinked hose
must be replaced.
When using a chain to lift the
pump, please observe the rel-
evant national regulations re-
garding accident prevention. Lifting
gear must be checked regularly by an
expert in accordance with the legal reg-
ulations.
Oil check
The oil reservoir is sealed on the outside
with a brass screw. In order to check the
mechanical seal, the oil, including any
residue, must be drained from the oil
reservoir and collected in a clean meas-
uring container.
∙ If the oil is contaminated with water
(milky), an oil change must be car-
ried 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 mechanical seal as well.
For monitoring the oil reservoir, it is also
possible to retrofit the electrode of our
“DKG” seal leak control device in place
of the brass screw on the oil reservoir.
Changing the oil
To ensure operational reliability, the
first oil change should be carried out
after 300 operating 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
constituents is being pumped, the oil
changes should be carried out at cor-
respondingly shorter intervals.
Use HLP hydraulic mineral oil, viscosity
class 22 to 46, e.g. Mobil DTE 22, DTE
24, DTE 25, to replace the oil in the oil
reservoir.
The quantity of oil required is 700 cm³
for the US 253, 500 cm³ for the US 251
and US 251 and 300 cm³ for all other
US pumps.
Attention!
The oil reservoir must only
be filled with the specified quantity of
oil. Overfilling will result in the pump
being rendered inoperable.
Cleaning
The foot strainer prevents coarse impu-
rities from entering the pump. Regular
cleaning of the float and the foot strain-
er ensures optimum performance and
operation.
To clean the impeller in the event of
an obstacle or blockage, the hexagon
socket screws on the underside of the
pump must be removed and the foot
strainer or cover must be levered off.
On pumps with a 10 mm free passage,
the wear plate must be removed. The
impeller can now be cleaned.
Worn impellers can have sharp
edges.
Tightening torque M
A
for A2 screw ma-
terials
for M 6 M
A
= 8 Nm
for M 8 M
A
= 20 Nm
for M 10 M
A
= 40 Nm
for M 12 M
A
= 70 Nm
Quick tips for remedying
faults
No pump operation
∙ 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 the pressure pipe or hose to
allow the non-return valve to open
and the air to escape from the pump
housing.
Impeller blocked
∙ Solids and fibrous matter have be-
come lodged in the pump housing =
clean
Decreased pumping performance
∙ Pump housing obstructed = clean
∙ Impeller worn = replace
∙ Wrong direction of rotation (for a
three-phase current) = ask a quali-
fied electrician to change 2 phases of
the supply line
