KSB HPK, Installation & Operating Manual

Page: 35 / 72

6 Commissioning/Start-up/Shutdown
35 of 72
HPK
Table 14: Permissible ambient temperatures
Permissible ambient temperature Value
Maximum 40 °C
Minimum See data sheet.
6.2.2 Frequency of starts
DANGER
Excessive surface temperature of the motor
Explosion hazard!
Damage to the motor!
▷ In case of explosion-proof motors, observe the frequency of starts specified in
the manufacturer's product literature.
The frequency of starts is usually determined by the maximum temperature increase
of the motor. This largely depends on the power reserves of the motor in steady-
state operation and on the starting conditions (DOL, star-delta, moments of inertia,
etc). If the starts are evenly spaced over the period indicated, the following limits
serve as orientation for start-up with the discharge-side gate valve slightly open:
Table 15: Frequency of starts
Motor rating Maximum frequency of starts
[kW] [Starts/hour]
≤ 12 15
≤ 100 10
> 100 5
CAUTION
Re-starting while motor is still running down
Damage to the pump (set)!
▷
Do not re-start the pump set before the pump rotor has come to a standstill.
6.2.3 Fluid handled
6.2.3.1 Flow rate
Unless specified otherwise in the characteristic curves or in the data sheets, the
following applies:
▪ Short-time operation: Q
min
5)
= 0.1 × Q
opt
6)
▪
Continuous operation: Q
min
5)
= 0.3 × Q
opt
6)
▪ 4-pole operation: Q
max
7)
= 1.25 × Q
opt
6)
The data refer to water and water-like fluids. Longer operating periods with these
fluids and at the flow rates indicated will not cause an additional increase in the
temperatures on the pump surface. However, if the physical properties of the fluids
handled differ from those of water, the calculation formula below must be used to
check if an additional heat build-up may lead to a dangerous temperature increase at
the pump surface. If necessary, the minimum flow must be increased.
5)
Minimum permissible flow rate
6)
Flow rate at best efficiency point
7)
Maximum permissible flow rate