Flow Velocity "V" Past The Motor - KSB S 100D Booklet

Flow Velocity v Past the UMA Submersible Motor
Depending on the general installation arrangement (i.e. depending, for example, on the ratio of outside motor diameter to inside
well or shroud diameter, etc.) a distinction must be made between the following cases ...
a) v = 0 m/s ... this applies, for example, when the pump set is installed in a deep well below the well screen / filter,
in a pump sump, tank or other reservoir, etc.
Caution: At v = 0 m/s, UMA 250D motors can only be operated at reduced rated power.
b) v ≥ 0.2 m/s ... this describes with adequate accuracy the case when the pump set is, for example, installed in a deep well above
the well screen / filter, etc. In borderline cases (for ex. if the inside well diameter is very large compared with the
outside motor diameter) the diagram below can be used to double-check the data.
c) v ≥ 0.5 m/s ... In this case it must always be checked, using the diagram below, whether the installation dimensions
(i.e. the ratio of outside motor diameter to inside well diameter) are adequate to ensure a minimum flow velocity
past the motor of v ≥ 0.5 m/s. If not, use a special cooling shroud.
How to read the diagram:
The requirement for a "flow velocity past the motor of v ≥ 0.2 or 0.5 m/s" is met, if the point of intersection of the capacity Q and
the inside well or shroud diameter DN is located on or to the right of the curve applicable to the submersible motor used.
Max. permissible well diameter for compliance with
1400
1200
∅
[mm]
1000
800
DN 100V ≥ 0.1
600
400
200
0
0 100
Example:
Given: UPA 300 - 65/4 + UMA 250D 160/21 and v ≥ 0.5 m/s.
3
Found: For Q = 250 m
This means that the requirement for v ≥ 0.5 m/s is met, if the pump set is, for example, installed in a well or cooling shroud of
DN ≤ 700 mm or ≤ 28 inches.
112
required flow velocity past the motor
200 300
/h ( Q ) the following applies: ⇒ DN ≤ 700 mm.
¶
opt
60 Hz
400 500 600
Submersible borehole pumps
V >= 0.2 m/s
V >= 0.5 m/s
UMA 300D
UMA 250D
UMA 200D
UMA 150D
DN 100
700 800 900
Q [m#/h]