KSB HPK-L, Installation & Operating Manual

Page: 41 / 74

6 Commissioning/Start-up/Shutdown
41 of 74
HPK-L
1136.8/15-EN
6.2.3 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 determined by the maximum temperature increase of the
motor. The frequency of starts depends on the power reserves of the motor in
steady-state operation and on the starting conditions (DOL starting, star-delta
starting, moments of inertia, etc). If the start-ups are evenly spaced over the period
indicated, the following limits serve as orientation for start-up with the discharge-
side shut-off 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.
6.2.4 Fluid handled
6.2.4.1 Flow rate
Unless specified otherwise in the characteristic curves or in the data sheets, the
following applies:
▪ Short-time operation: Q
min
6)
= 0.1 × Q
BEP
7)
▪ Continuous operation: Q
min
6)
= 0.3 × Q
BEP
7)
▪ 2-pole operation: Q
max
8)
= 1.1 × Q
BEP
7)
▪ 4-pole operation: Q
max
8)
= 1.25 × Q
BEP
7)
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.
×
×
×
6 Minimum flow rate
7
Flow rate at best efficiency point
8 Maximum flow rate