Klimor EVO-S COMPACT, Operation And Maintenance Manual, Page: 49 / 88

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4.6 VF Fan
The purpose of the fan is to force the air flow at a certain flow
rate and pressure. The fan is powered directly by the electric
motor shaft through a frequency converter (inverter).
Motor power supply: 1×230V or 3×400V 50/60Hz.
Fans without housing type PF (plug-fan) with direct drive
with EC motors are used.
Fan unit and inlet funnel is fixed to the section diaphragm.
The maximum air temperature at the air handling unit op-
eration is +45˚C, however, due to the acceptable operating
temperature of the electric motor, it is necessary to take into
account the power drop according to the table below.
Table 15 Power correction factor for electric motors depending on ambient temperature
Power correction factor depending on the ambient temperature
Max. ambient temperature ° °C 40 45 50 55 60
P/PN % 100 97 93 87 82
4.6.1 Operating instructions for fan units
Prior to commencing any works on the unit and when
removing the inspection panels, one should make sure that
the unit has been disconnected from power supply, the rotor
is fan not turning, the fan motor has cooled down and that
the system has been secured against accidental start-up.
In case of an fan the following should be checked:
• whether the rotor is clean (clean with a vacuum cleaner
and clean wet with a mild cleaning agent),
• whether the rotor turns easily,
• whether the rotor is balanced and does not run out,
• whether it has not moved in relation to the nozzle (di-
mensions of appropriate slots retained),
• all mounting bolts (if necessary they should be tight-
ened).
In case of an electric motor the following should be checked:
• correct fixing of all mechanical and power connections,
• quality of conductors and isolation
• whether there are any discolourations
• isolation resistance of windings
• that there are no grease leaks
• casing soiling (clean dry with a soft brush or blow
through with compressed air)
4.6.2 Pressure measurement orifice
After start-up of the air handling unit, it is recommended to
measure the actual intake and outlet air flow rate.
For this purpose, EVO series air handling units can be equip-
ped with a connection set for measuring pressure drop on
the orifice. Outside the fan section, two measuring stubs are
mounted to which a pressure transducer or pressure gauge
is connected in order to measure the differential pressure
Δpw.
Fig. No. 37 Diagram of the fan section with mounted stubs for measuring the output
1 - mounting stub connected to (+) pressure gauge; transition to
the suction chamber of the fan
2 - mounting connection to (-) pressure gauge; connection to fan
nozzle
From the measured differential pressure and the follo-
wing formula, the current air flow can be calculated (for
an air temperature of 20°C).
In case of multi-fan units, the stub is connected to one
of the fans.
Qv=n
w
k√(Δp
w
)
Qv - airflow rate [m3/h]
n
w
- number of fans in the set
k - characteristic coefficient for the fan nozzle
Δp
w
- static pressure drop on the fan nozzle [Pa]
Fig. No 38 Differential pressure measurement scheme on the fan orifice
Table 16 K-factors for EBM-PAPST fan nozzles
Fan type K-factor Fan type K-factor
R3G250RR01-H1 68 R3G250-PR17-I1 76
R3G280-PR04-I1 77 R3G280-PS10-J1 77
R3G310-AX54-21 116 R3G310-BB49-01 116
R3G355-AY43-21 148 R3G355-PI93-01 148
R3G400-PI92-01 188 R3G355-BC92-01 148
R3G450-PB24-01 240 R3G400-AQ23-68 188
R3G500-PB33-01 281