Centrifugal Fans AT belt driven - Nicotra Gebhardt

Description
Sound
240
L Wfc6 = L Wfc4 + L Wer
Explosion protection according to ATEX
Belt Driven Centrifugal Fans / Description
For a free discharge situation i.e. without duct connected the sound level will be lower
because of an end reflection.
This is specially true for low frequencies. For this case a correction may be applied to
L Wfc4 of the first 3 octave bands as follows:
ADH / AT / RDH / RZR f c 63 125 250 Hz
0160/-0280 L Wer -14 -9 -4 dB
0315/-0800 L Wer -9 -4 -2 dB
0900/-1600 L Wer -4 -1 0 dB
Fans for use in explosive atmospheres must comply with EC Directive 94/9/EG
(ATEX 95). Equipment in Group II (all applications except mining) is categorised in
accordance with the required degree of safety for designated use in equipment categories
1, 2 and 3. Depending on suitability, a distinction is in addition made between
G (gas, vapours) and D (dust).
Harmonised European standards and national guidelines must be observed. Equipment
in class 2 and 3 is not subject to compulsory specifications nor to type testing.
The manufacturer declares conformity with the EC directive.
For the standard designs of our fans, the following ignition sources are essentially
to be considered:
A Hot surfaces, e.g. due to heat of friction or seizure of a bearing or due to blockage
of an impeller
A Rubbing-, grinding- or beating sparks, e.g. as a result of contact of the impeller with
stationary components
A Sparks resulting from discharge of electrostatically loaded, non-conducting omponents,
e.g. of plasticpanels, surfaces with strong layer thickness.
Preconditions for operating:
A In the proximity of the motor, the temperature limits -20 °C and +40 °C must
not be exceeded.
A The temperature limits of -20 °C und +60 °C for the flow medium must not
be exceeded. If the temperature of the flow medium should exceed +60 °C
on the pressure side, then the fan must be switched off!
A The fans may only be employed with a horizontal shaft.
A The fans are to be protected against the falling-in or sucking-in of foreign
objects. Protection guards must be ordered separately as an accessories.
A On the machine plate the max. permitted fan speed is indicated.
A Fans for operation in ex-hazardous areas are marked as such on the machine
plate and they are accompanied by an EU conformity declaration and
with operation and maintenance instructions.
The operation and maintenance instructions have strictly to be observed.
The conformity is always related to the fan system supplied.
If the fan is completed with motor and belt drive by the customer the conformity of
this fan set has to be declared at new.
Fans of the series ADH / AT / RDH in ATEX-Execution on request.