DRAE

Centrifugal fans with slippage characteristics double inlet

DRAE... / DRAD... - Centrifugal fans double inlet with slippage characteristics


·    Casing made of galvanized sheet steel
·    Steep volume-pressure-performance curve
·    outgoing connection cable
·    motor protection by termal contacts
·    speed is variable using auto transformers

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Description:

The high efficiency centrifugal fans with backward curved impellers have been developed especially for  modern  ventilation by  use of a special designed external rotor motor with high rotor resistance,  in connection with forward curved centrifugal impellers,  we  developed  a  centrifugal  fan  series with extremely high slippage characteristics.  The external rotor motor adjusts to the operating conditions and therefore changes the R.P.M. at varying system resistances regarding on the total
pressure.  This  is a special advantage in systems with variable resistances occurred from dirty filters, controlled dampers in duct installations or clean-room applications.


Application areas:
Railway  / Wind power /  Ex-protection /   Datacenters /   Inflatables /   Compressors /  Ships /  Offshore /  Laboratories / Retail stores / Industrial buildings / Basement rooms / Workshops

Reference to Directives:
 Declaration of incorporation and operating instruction are according to Machinery Directive 2006/42/EC, CE identification in accordance to EMC-Directive 2014/30/EU, Low Voltage Directive 2014/35/EU and the Ecodesign-Directive 2009/125/EC.

_____________________________________________________________________________________________________

Casing:

The spiral scrolls are made of galvanized sheet steel.
On request plastic coating is possible.

_____________________________________________________________________________________________________

Impellers:

The impellers are balanced together with the external rotor motors at two levels according to quality level G2.5 to DIN 1940.

Forward curved centrifugal impellers in double inlet variant made of galvanized sheet steel.

_____________________________________________________________________________________________________

Motor and motor protection:

All Rosenberg fans are equipped with direct driven external rotor motors. All our fans have motor protection through thermal contacts in the motor windings as standard. The motors apply to protection class IP44/IP54.


The drive has due to an external rotor motor a space saving, compact and attractive design. The motor is  fitted within the impeller,  which  enables the best possible cooling. For this reason a 100% variable speed  control can be guaranteed. V-belts, additional tension bars and motor mounting devices are not necessary.  Only  well-dimensions  ball-bearings,  fitted  on  both sides and life time greased are used.
Both  ball-bearing  seats  are  ground to high precision in one work process to eliminate any vibrations.
External rotor motors have extremely low starting current. The windings comply to isolation class F.
In addition the windings have a standard moisture impregnation.

_____________________________________________________________________________________________________

Electrical connection:

The motors are fitted with an outgoing cable. The electrical connection can be made via an IP44 terminal box, which is supplied loose.

_____________________________________________________________________________________________________

Installation:

Direction of rotation:
Direction of rotation for the fan types DRAE and DRAD is counter-clockwise viewed from the cable outlet.

_____________________________________________________________________________________________________

Air volume control:
For more information see accessories!

5-speed control:
230V à    RTE
400V à    RTD

Infinitely variable control:
230V à    not possible
400V à     RED

_____________________________________________________________________________________________________

Scope of delivery:

  Centrifugal fan (DRAE / DRAD)
  Terminal box (loose)
  Documentation

_____________________________________________________________________________________________________

Important notes:

Air performance curves:
The performance curves for these fan types have been measured in mounting position B (installed on the pressure side and open on the suction side) and show the total pressure increase ∆pt as a function of the air flow.  The dynamic pressure ∆pd2 refers to the flange cross section at the outlet side of the fan.

Noise levels:
The  bordered  values  printed  in the performance curve diagrams show the "A" weigthed LWA6 sound power level (fan outlet). Determination of "A" weigthed LWA5 sound power level at fan inlet:
Up to size 282:   LWA5 [dB(A)] = LWA6 [dB(A)] - 2 dB
From size 314:   LWA5 [dB(A)] = LWA6 [dB(A)] - 4 dB
The "A" weighted sound pressure level LPA at a distance of 1 metre is calculated approximately by  deducting 7 db(A) from the "A" weighted sound power level. It is importmant to note that the reflection and room characteristic as well as natural  frequencies  influence  the sound pressure levels a different way.  The octave sound power level LWA at octave medium frequency you can find on the table on each fan type page.

Classification of the fan series:
NRVU    = Non Residential Ventilation Units
UVU    = Unidirectional Ventilation Units

Erp-Information:
Rosenberg fans have a spezfic (pressure-) ratio < 1,05 (pressure < 5000 Pa).

Service life:
For maximum service life of Rosenberg products please beware of the maintenance hints on the manual for each
product type.

Recycling and disposal:
For recycling and disposal of Rosenberg products comply with applicable locally requirements and regulations.
 

Centrifugal fans with forward curved impellers and slippage characteristics, Types ERA.../ DRA...

Single and double inlet casings, made from galvanized steel, with spiral scroll. Impellers with forward curved blades made from galvanized steel, mounted onto the rotor of a speed controllable external rotor motor. The fan is balanced on two levels according to quality class G 2.5, DIN/ISO 1940.

Closed motor, protection class IP 44/54 with protection against humidity and thermal contacts for motor protection. Maintenance free ball bearings, closed on both sides, sealed for life. Electrical connection through terminal box (not connected) in IP 44.

Reference to Directives:
Declaration of incorporation and operating instruction are according to Machinery Directive 2006/42/EC, CE identification in accordance to EMC-Directive 2014/30/EU, Low Voltage Directive 2014/35/EU and the Ecodesign-Directive 2009/125/EC.

For further information, please click the model below for detail.

Picture of Centrifugal fans double inlet with slippage characteristics

Centrifugal fans with forward curved impellers double inlet

DRAE... / DRAD... - Centrifugal fans double inlet with forward curved centrifugal impellers


·    Casing made of galvanized sheet steel
·    outgoing connection cable
·    motor protection by termal contacts
·    speed is variable using auto transformers

_____________________________________________________________________________________________________

Description:

The high efficiency centrifugal fans have been developed especially for modern ventilation and air conditioning applications and are ideal for the movement of air and slightly aggressive gas and vapours. The sizes comply with standard R20 according to DIN 323. The designation of sizes corresponds to the outside diameter of the impeller.


Application areas:
Railway  / Wind power /  Ex-protection /   Datacenters /   Inflatables / Compressors / Ships / Offshore / Laboratories / Retail stores / Industrial buildings / Basement rooms / Workshops

Reference to Directives:
 Declaration of incorporation and operating instruction are according to Machinery Directive 2006/42/EC, CE identification in accordance to EMC-Directive 2014/30/EU, Low Voltage Directive 2014/35/EU and the Ecodesign-Directive 2009/125/EC.

_____________________________________________________________________________________________________

Casing:

The spiral scrolls are made of galvanized sheet steel.
On request plastic coating is possible.

_____________________________________________________________________________________________________

Impellers:

The impellers are balanced together with the external rotor motors at two levels according to quality level G2.5 to DIN 1940.

Forward curved centrifugal impellers in double inlet variant made of galvanized sheet steel.

_____________________________________________________________________________________________________

Motor and motor protection:

All Rosenberg fans are equipped with direct driven external rotor motors. All our fans have motor protection through thermal contacts in the motor windings as standard. The motors apply to protection class IP44/IP54.


The drive has due to an external rotor motor a space saving, compact and attractive design. The motor is  fitted within the impeller,  which  enables the best possible cooling. For this reason a 100% variable speed  control can be guaranteed. V-belts, additional tension bars and motor mounting devices are not necessary.  Only  well-dimensions  ball-bearings,  fitted  on  both sides and life time greased are used.
Both  ball-bearing  seats  are  ground to high precision in one work process to eliminate any vibrations.
External rotor motors have extremely low starting current. The windings comply to isolation class F.
In addition the windings have a standard moisture impregnation.

_____________________________________________________________________________________________________

Electrical connection:

The motors are fitted with an outgoing cable. The electrical connection can be made via an IP44 terminal box, which is supplied loose.

_____________________________________________________________________________________________________

Installation:

Direction of rotation:
Direction of rotation for the fan types DRAE and DRAD is counter-clockwise viewed from the cable outlet.

_____________________________________________________________________________________________________

Air volume control:
For more information see accessories!

5-speed control:
230V à    RTE
400V à    RTD

Infinitely variable control:
230V à    not possible
400V à     RED

_____________________________________________________________________________________________________

Scope of delivery:

  Centrifugal fan (DRAE / DRAD)
  Terminal box (loose)
  Documentation

_____________________________________________________________________________________________________

Important notes:

Air performance curves:
The performance curves for these fan types have been measured in mounting position B (installed on the pressure side and open on the suction side) and show the total pressure increase ∆pt as a function of the air flow.  The dynamic pressure ∆pd2 refers to the flange cross section at the outlet side of the fan.

Noise levels:
The  bordered  values  printed  in the performance curve diagrams show the "A" weigthed LWA6 sound power level (fan outlet). Determination of "A" weigthed LWA5 sound power level at fan inlet:

LWA5 [dB(A)] = LWA6 [dB(A)] - 3 dB

The "A" weighted sound pressure level LPA at a distance of 1 metre is calculated approximately by  deducting 7 db(A) from the "A" weighted sound power level. It is importmant to note that the reflection and room characteristic as well as natural  frequencies  influence  the sound pressure levels a different way.  The octave sound power level LWA at octave medium frequency you can find on the table on each fan type page.

Classification of the fan series:
NRVU    = Non Residential Ventilation Units
UVU    = Unidirectional Ventilation Units

Erp-Information:
Rosenberg fans have a spezfic (pressure-) ratio < 1,05 (pressure < 5000 Pa).

Service life:
For maximum service life of Rosenberg products please beware of the maintenance hints on the manual for each
product type.

Recycling and disposal:
For recycling and disposal of Rosenberg products comply with applicable locally requirements and regulations.
 

For further information, please click the model below for detail.

Picture of Centrifugal fans with forward curved impellers Single inlet

Picture of Centrifugal fans with slippage characteristics Single inlet