Preventing Backflow; Calculating The Total Weight - KSB UPA Installation & Operating Manual

11
See product literature of the riser used.
12 Applies to pumps with lift check valve if no other measures to drain the riser have been taken.
30 of 98
5 Installation at Site

5.2.5 Preventing backflow

DANGER
Uncontrolled backflow of the fluid handled turning the magnet rotor in the UMA-
S 150, UMA-S 200 and UMA-S 250 submersible motor
The rotating permanent magnet rotor may generate an electric current at the
motor lead ends!
Danger of death from electric shock!
▷ Take suitable precautions to prevent any inadvertent rotation caused by
uncontrolled backflow of the fluid handled.
▷ Make sure the motor cannot be rotated inadvertently.
▷ Observe the safety regulations that apply to work involving electrical hazards.
Verify that the equipment is de-energised.
DANGER
Electrical equipment overloaded by uncontrolled rotation of the magnet rotor of a
UMA-S 150, UMA-S 200 or UMA-S 250 submersible motor
Danger of death from electric shock!
▷ Take suitable precautions to prevent any inadvertent motor rotation caused by
uncontrolled backflow of the fluid handled.
▷ As an option, provide electrical protection devices between the motor and the
frequency inverter, such as fuses or circuit breakers.
CAUTION
Uncontrolled backflow of the fluid from the riser
Damage to the pump set!
▷ Prevent any uncontrolled backflow of the fluid handled with suitable means.
▷ Make sure that backflow of the fluid handled is slow and controlled, so that
the pump rotor does not start to rotate, e.g. by throttling the discharge-side
gate valve accordingly.
The submersible borehole pumps generally feature an integrated lift check valve.
On pump sets without lift check valve the operator must prevent any uncontrolled
backflow of the fluid, e.g. by structural means. Otherwise the pump could be
operated in the wrong direction of rotation and critical speeds could be exceeded.
If backflow rotates submersible motors of the UMA-S 150, UMA-S 200 or UMA-S 250
type series, a hazardous voltage will occur at the motor lead ends.
If the submersible motor is connected to the power supply, excessive induction
voltage can lead to overloading (short circuit) of the electrical equipment. This must
be prevented at all times. Provide electrical protection devices as an option.

5.2.6 Calculating the total weight

One or several pieces of suitable lifting equipment, e.g. tripod or crane, are required
for installing and removing submersible borehole pumps.
The load-carrying capacity of the lifting equipment must be larger than the weight
11)
of the pump set + riser + water column
For the weights see the other applicable documentation and the following table.
UPA / UPA S
12)
in the riser + power cable + holders.