6 Commissioning/Start-up/Shutdown
41 of 78
Etanorm-R
1222.8/13-EN
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 12:
Frequency of starts
Motor rating
Maximum frequency of starts
[kW]
[Starts/hour]
≤ 12
15
≤ 100
10
> 100
5
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.
6.2.3 Fluid handled
6.2.3.1 Flow rate
Table 13:
Flow rate
Minimum flow rate
Maximum flow rate
For a short period
(approximately 2 minutes)
≈ 25 % of Q
Opt
7)
See hydraulic characteristic
curves
Continuous duty
Q
Part load
≥ 45 % of Q
Opt
7)
The calculation formula below can be used to check if an additional heat build-up
could lead to a dangerous temperature increase at the pump surface.
×
×
×
Table 14:
Key
Symbol
Description
Unit
c
Specific heat capacity
J/kg K
g
Acceleration due to gravity
m/s²
H
Pump discharge head
m
T
f
Fluid temperature
°C
T
O
Temperature at the casing surface
°C
Pump efficiency at duty point
-
Temperature difference
K
6.2.3.2 Density of the fluid handled
The power input of the pump set will change in proportion to the density of the fluid
handled.
7
Best efficiency point
Summary of Contents for Etanorm-R
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