lenze americas articles

Lenze 3 Phase Squirrel Cage Induction Motors

Lenze 7/18/2018

Lenze MDERA AC Motors

Lenze are a leading international company in design and manufacture of drive and automation products. With 3000 employees worldwide, sales and technical expertise is in place in over 50 countries.

The Lenze MDERA series are 3 phase asynchronous motors with totally enclosed fan cooled (TEFC) design. Suiting general purpose use, they combine Lenze quality with competitive pricing in 2, 4 and 6 pole speeds from 56 to 355 frame.

• Aluminium frames 56-132, cast iron 160-355
• Detachable multi-position feet 56-132 frame
• Large terminal box with 2 glands
• Enclosed to IP55, insulation class F
• Meets level Eff2 of European efficiency scheme
• Suiting European supply of 400V
• Dual frequency 50 and 60Hz
• Choice of foot, flange and face mountings
• European C3 bearings
• General purpose motors suiting most industrial applications
• 2 year warranty and Lenze worldwide service

Aluminum alloy framed motors are available in a stock range from 56-132 frame. Fan guards are sheet metal and European shielded ball bearings are used. Motors 160 to 355 frame have cast iron construction.

MDERA motors meet the level Eff2 of the CEMEP European guidelines. This is typically 1 to 4% below level Eff1 but data relates to full load operation and running any motor at part loads can lead to losses greater than that. The efficiency of motors running under variable load conditions can be optimised using a frequency inverter to vary speed with savings of up to 50%. Your Lenze salesman can advise.

Motors are available with B3 foot, B5 flange and B14 face mounting. B3 motors with aluminium frames 56-132 feature bolt- on feet that can be repositioned in increments of 90o. Cast iron framed motors have integral feet. Motors with B14 mounting have 8 tapped holes to allow 45 degree increments of the terminal box. Use connection flanges that cover any unused holes in order to maintain IP55 protection.

Terminal boxes/cable glands
Frame sizes 056 to 132 have a single cable gland (dimension KK), plus a M16x1.5 gland fitted with a blanking plug to suit PTC/Klixon cables, mounted on the same side. Frame sizes 160 to 355 have two cable glands (dimensions KK) plus a M16x1.5 gland fitted on the opposite side.

MDERA motors are designed for nominal speeds 3000, 1500 and 1000r/min at 50Hz supply frequency (750 r/min on request). With a 60Hz supply and the same voltage speeds increase by 20% but output power remains the same so torque falls by 17%.

Operating at 87Hz
Motor power ratings can be increased by 73% in frame sizes up to 100 by running with inverter operation at a nominal frequency speed of 87Hz. This also gives a wider speed range and increased starting torque. Call us for more information.

Self-cooled motors without forced ventilation from blowers require derating if they are to be run continuously at lower speeds. See diagram below:


Supply Up to 3kW:
230/400V/3phase/50Hz +10%
277/480V/3phase/60Hz +10%

Supply 4kW and above:
400V /3phase/50Hz +10%
480V /3phase/60Hz +10%

Up to 3kW motors accept 230V 3phase supply suiting use with single power inverters. From 4kW motors suit star/delta starting giving a softer start with lower current peaks. Other supply voltages available on request.

To the level Eff2 defined by CEMEP and the European Commission.

Ambient conditions
Ambient temperatures between -15 and +40oC and sites up to 1000m a.s.l. Derating applies outside these limits. Relative humidity 30-95% without condensation. Enclosure class IP55 with insulation to class F. Maximum voltage amplitude u = 1.5kV Maximum rate of voltage rise 5kV/µs.

Rated for continuous duty S1. Motors up to 132 frame have a Klixon thermal switch. From 160 frame three PTC thermistors are fitted in the windings.
Derating may be necessary for continuous running with inverters below 20-25Hz.

Motors are supplied painted to basalt grey RAL7012 except B14 models 56-132 frame which are unpainted and have zinc plated cowls.

Construction standards
Designed and constructed meeting the European Directives for Low Voltage, Machinery and EMC. Complies with relevant IEC, BS, VDE and DIN standards. CE marked. Lenze is certified to ISO9001:2000.