English
Installation and operating instructions Wilo-Drain STS 65
17
NOTE: When drafting a maintenance plan, expen-
sive repairs can be avoided and a fault-free oper-
ation of the system can be achieved with a
minimum of maintenance effort. The Wilo-after-
sales service is available for commissioning and
maintenance work. A maintenance report must be
issued.
9.2 Maintenance procedure
• Open pump sump, station and ventilate.
• Inspect the inside visually
• Deposits on the pump, sump floor and on the
accessories
• Shut off sewage inlet(s) (e.g. with air plugs)
• Measure the pump delivery head when Q = 0 m³/h.
• If the flow rate of the pump drops by more than
10 %, lift it out of the sump. Then check the
impeller and the pump housing for wear.
• Check the sump level.
• Drain the sump manually until slurping operation.
• Check the sump floor for deposits.
• Clean the sump if there are major deposits.
• Fill the sump and carry out a trial run.
• If the delivery head cannot be measured
• Wait until the sump is filled and the pump starts
up
• Measure the time between switching on and off
(t) and also the drop in level (
h).
• Calculate the flow rate according to the follow-
ing formula.
With the horizontal section A, the following gen-
eral formula can be used:
Q [m³/h] = 36 x A [m
2
] x
h [cm] / t [s]
9.3 Oil change
WARNING! Risk of injury!
The pumps are heavy and can fall over.
People may be injured if the pump is not prop-
erly secured during maintenance work.
Always check the stability of the pump and use
suitable hoisting gear.
WARNING! Risk of injury!
An overpressure may prevail in the sealing
chamber/separation chamber.
If the oil drain plug is undone, hot oil may spurt
out under pressure and cause injury or scalding.
Before changing the oil, put on protective gog-
gles and undo the oil drain plug with care.
WARNING! Danger to the environment
!
Oil may leak out if the pump is damaged or dis-
mantled.
This can damage the environment.
Avoid damage and adopt suitable measures to
take up the oil.
Have the oil changed once a year or after 1000
operating hours during a maintenance operation.
• Provide suitable hoisting gear depending on the
weight of the pump.
• Oil type and fill volumes: see 5.2 Technical data.
NOTE: When you change the oil, the old oil and
water have to be disposed of as hazardous waste!
Sump type
Formula
WB 100
Q [m³/h] = 28,3 x
h [cm] / t [s]
WB 150
Q [m³/h] = 63,6 x
h [cm] / t [s]
WB 200
Q [m³/h] = 113,1 x
h [cm] / t [s]
Square sump Q [m³/h] = 36 x A [m] x B [m] x
h [cm] / t [s]
