“MERCOR” SA
– The company reserves the right to modify and change the document
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4.3. Versions ______________________________________________________________________
dual speed jet fans, single-direction - U
dual speed jet fans, reversible - R
Versions ___________________________________________________________________________
Polygonal, painted casing – O
Polygonal, steel casing – L
5. IDENTIFICATION MARKINGS ______________________________________
mcr Bora 40 - R - L - F400
Temperature category
Casing type
Airflow direction
Nominal size [diameter, cm]
Fan type
6. DESIGN AND OPERATING PRINCIPLE _____________________________
6.1 Design _________________________________________________________________________
The mcr Bora jet fan comprises an electrical motor with a suitable insulation class, an axial rotor, a blade
assembly, an outer casing assembly and silencers.
The motor is coupled directly to an aluminium rotor on bearings, and on the rotor the profiled blades are
installed. The angle and number of blades depend on the required thrust and capacity of the fan. The
motor bearings are high temperature resistant and maintenance free. On the inlet and outlet side the
engine is connected to silencers. The medium, which is fire gases and air with smoke, flows through the
casing, the motor, the rotor blades and the silencer.
The mcr Bora fans in O and L versions have a connection box located on the casing.
All types of fans have fasteners or assembly frames, depending on the fan size.
6.2 Function _______________________________________________________________________
The fan does not run while in standby. When 3-phase voltage is present on the terminal box terminals,
the fan is started and running.
6.3 Dimensions and technical features __________________________________________
The basic dimensions of fans as well as their technical parameters are given below.
