Installation
5-6
WILO EMU 3.0
Dry-run protection
The machine must always be submerged up to the top edge of the pump housing. Make sure that
no air enters the pump housing.
For optimum reliability, we recommend installing a dry-run protection system. Correct running is
ensured by float switches or electrodes. The float switch / electrode is fastened in the pit and
switches off the machine when the water level falls below the minimum coverage level.
For dry installations, the float switch must be fitted at an appropriate height in the collector tank.
Please observe the information about the minimum water coverage.
If dry-run protection is only put into effect with one float or electrode
when filling levels deviate strongly, then the machine may turn on and
off constantly!
This can result in the maximum number of motor start-ups being
exceeded.
Corrective measures
Manual reset
The motor is switched off when the water level falls below the minimum coverage level and
switched back on when a sufficient water level is reached.
Separate reactivation point
Using a second switching point (additional float or electrode), a sufficient difference is obtained
between the activation and deactivation points. This prevents constant switching. This function
can be put into effect with a level control relay.
Removal
When removing the machine, make sure that it is first disconnected from the mains.
For
dry installations
, the piping system must be drained or shut off. Afterwards, the machine can
be disconnected from the pipeline and lifted out of the operating area with a hoisting gear.
On
portable installations
, the machine can be lifted out of the pit after it has been disconnected
from the mains and the discharge pipe has been emptied. You may have to disconnect the hose
first. Here too, you should use appropriate lifting gear if the pit is deep, or the machines are heavy.
On
wet installations
with suspension units, the machine is raised out of the pit using the chain or
lifting cable with the help of a hoisting gear. This does not have to be emptied especially for this
purpose. Make sure the power supply cable does not become damaged.
Beware of poisonous substances!
Machines which pump fluids hazardous to health present a fatal
risk. These machines must be decontaminated before any other
work is carried out. Wear the necessary protective clothing/
equipment when doing so.
