5 Installation at Site
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UPAchrom
Parameter/function
Setting
Deceleration (run-down) time / stop ramp t
A
< 4 seconds
All special functions, e.g.
▪
Delayed starting
▪
Current control
▪
Speed control
▪
Kick-start / boost function
OFF
1.
After run-up, the soft starter must be bypassed by a contactor.
2.
Always observe the manufacturer's operating instructions.
3.
Soft starters for two-phase connection are only permitted if the starter's control
algorithm eliminates the physically caused DC components.
4.
If the soft starter fulfils motor protection functions, such as an over-current trip
(tripping class 10 or 10A), phase failure, etc., these functions must also be
ensured when the soft starter is bypassed.
NOTE
Conspicuous noises or vibrations during run-up and run-down could indicate
incorrect parameter settings on the soft starter, such as excessive ramp times,
incorrect operating mode (control) or enabled special functions.
5.4.3 Operation on a frequency inverter
If KSB's submersible borehole pumps are operated on a frequency inverter, the
pumps' special design (low moment of inertia, high output per size, etc.) requires
that the following points be observed.
Power reserve
If supplied by KSB for operation on a frequency inverter, see data sheet, the motor
comes with a 5 % power reserve. If the submersible borehole pump is retrofitted
with a frequency inverter, an electrical loss of 5 % has to be taken into account. To
check whether a frequency inverter can be retrofitted, always contact the pump
manufacturer.
Maximum permissible run-up and run-down time
The run-up time from standstill to the minimum frequency f
min
must not exceed
2 seconds. The run-down time must also be limited to a maximum of 2 seconds.
Minimum frequency
The minimum frequency must not be below 30 Hz.
Maximum operating frequency
Do not exceed the maximum operating frequency of 50 Hz/60 Hz respectively.
Maximum permissible rate of voltage rise and voltage peaks
Observe the following limits:
▪
Maximum rate of voltage rise: du/dt ≤ 500 V/μs
▪
Maximum peak voltages to earth: J1 insulation ≤ 600 V
NOTE
Compliance with these limits can usually be assured by means of a sine filter or
du
/
dt
filter.
Control principle of the frequency inverter
The control principle has to correspond with a linear V/f characteristic. If other
control principles are employed, such as field-oriented inverters, inverters with DTC
or NOF, the manufacturer of the frequency inverter must ensure that the special
features of submersible motors (very small moment of inertia, electrical data) are
taken into account.
