Free running impeller with external rotor motor
· compact, space-saving design
· impeller with high power density
· constant high degree of efficiency
· mountable in all installation positions
· easy maintenance, due to lack of belt drive deterioration
· wide range of voltage- and frequency-controlled constructions
Features and Constructions:
Rosenberg centrifugal fans of ranges E/DKHR and E/DKHM with free running impellers out of aluminum are very compact units. The fans have been optimally designed with regard to air movement. They combine a voltage controlled AC-external rotor motor and a newly designed high efficiency impeller.
The combination of voltage controlled Rosenberg- external rotor motors, flexible production of impellers and high end metal fabrication, gives Rosenberg the capability to manufacture fan modules that provide the best possible benefit to customers while taking the design demands and the customers application into consideration.
· DKHR = Motorized impeller (inlet cone as accessory) (external rotor motor)
· DKHM = Fan module (external rotor motor)
Reference to Directives:
Declaration of incorporation and operating instruction are according to Machinery Directive 2006/42/EG, CE identification in accordance to EMC-Directive 2014/30/EU and the Ecodesign-Directive 2009/125/EG.
The impellers with backward curved blades are statically and dynamically balanced according to quality level G6.3 DIN ISO 1940.
The impellers with 8 backward curved blades are made of aluminum.
Special features concerning materials of the impeller on request.
Rosenberg external rotor motors of size 080 comply with protection class IP44 and the motors from size 106 and up adhere to protection class IP54. The winding insulation corresponds to insulation class F. Through the use of deep groove ball bearings, closed on both sides, with specially paired grease lubricant, maintenance-free and low-noise operation is guaranteed.
All motors are equipped with factory installed thermal contacts in the windings. Thermal contacts (TB) are temperature dependent control elements, controlling the winding temperature of the motor. If they are installed correctly, they protect the motor windings form overload, failure of a mains phase, standstill of the motor and from excessively high temperatures of the ventilated medium. We recommend the use of thermal contacts. We also offer 5-step speed controllers.
RTE and RTD types are equipped with thermal contact motor protection. An additional motor protection switch is not required.
The performance data as indicated on the performance curve charts are for the standard versions at 50Hz 1~230V and 3~400V. Motors for other voltages or frequencies are available upon request for an additional charge.
For 60Hz types (possible on request)
The nominal voltage indicated on the name plate is valid with a max. allowed voltage tolerance of ± 10%. The standard construction has the cable out on the side. The connection ends are stripped at 10 cm and supplied with end splices.
Standard cable length for motor size 80 and 106 is 68 cm and for motor sizes 137 and 165 is 88 cm from the motor flange.
Special cable lengths and fans with mounted terminal boxes are available upon request.
Air volume control:
Please note the new directive 1253/2014/EU (Lot 6) for ventilation units (ventilation fan), which is valid from 01.01.2016.
Keyword: "multistage drive" (min. 3 fix speeds, as well as speed 0 ("off")).
The required, system-specific, optimal setting of the desired operating point can only be attained with a suitable sytem for speed control. There are two common systems that can be used for speed controlling fans of this series.
Speed control is accomplished by reducing the terminal voltage. Using this method, the slippage is increased depending on the load and the speed is reduced. The air volume changes proportinally with the RPMs. All voltage controllable centrifugal fans in three-phase current construction can also be speed controlled by a frequency converter from the nominal frequency on down.
Frequency control for three-phase fans:
Speed control is accomplished by reducing the frequency through use of a frequency converter. The cut-off frequency, adjustable on the frequency converter , is 50Hz for all fans. With fans from the 60Hz list the frequency is 60Hz. Each performance curve show the max. frequency possible. With frequencies higher than the rated frequency the motor will thermally overload. For emergency operation or upon failure of the frequency converter, all frequency controllable types can be used direct with 400V on the 50Hz mains supply.
When operating the motors using a frequency converter the max. rate of voltage increase of 500V/µs must not be exceeded. Depending on the frequency converter type and the length of the cable between motor and frequency converter additional components may be required.
Single phase fans may not be operated on a frequency converter.
Air performance curves:
The performance curves for these fan types have been measured on a inlet side chamber testing platform according to DIN ISO EN 5801 in mounting position A (free inlet; free outlet) and are valid for air with a density of 1.2 kg/m³ and indicate the pressure increase Dpfa as a function of the air flow.
Rosenberg fans have a specific (pressure-) ratio < 1,05 (pressure < 5000 Pa).
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.
Rosenberg radial fans with free-running impeller
The single inlet, backward curved high efficiency impeller from sea-waterproof aluminium, mounted onto the speed controllable external rotor motor, equipped with an air flow optimized inlet cone from galvanized sheet steel. The impeller can be supplied as single unit or as a complete module of galvanized sheet steel.
The fan is balanced on two levels according to quality class G 2.5/6.3, DIN/ISO 1940.
Closed motor, protection class IP 44/54 with protection against humidity and thermal contacts wired in windings for motor protection. Maintenance free ball bearings, closed on both sides, sealed for life. Electrical connection through terminal box (not connected) in IP 44.
Declaration of incorporation and operating instruction are according to Machinery Directive 2006/42/EC, CE identification in accordance to EMC-directive 2004/108/EC and Low Voltage Directive 2006/95/EC. Motor operating instruction is available from motor manufacturer.
For further information, please click the model below for detail.
Picture of free running impeller fans DKH-W