The JJ Loughran engineering team were recently contracted by a customer to replace a defective bull electric DC motor and control techniques DC motor controller with a new Danfoss cabinet-built 460 Amp drive solution and an ABB AC designed 262.3KW, 2000rpm 200 Square frame motor complete with force ventilation.

The current application was unique, the existing Bull DC motor was used to run a large centrifugal fan which was used to cool toughen glass leaving EFCO Glass temperature Furnace.

It was diagnosed that the DC motor was near end of life with the communicator been reskimmed several times and the overall unit being overhauled on numerous instances. There was also significant and costly maintenance required with the upkeep and replacement of carbon brushes to also take into consideration. At this stage JJ Loughran advised the customer of an alternative replacement that would have not only a longer life but also a reduced maintenance commitment.

J J Loughran Engineers working in conjunction with ABB’s technical team selected the following square frame motor design. We utilised this design over a traditional squirrel cage design, to ensure customer modifications onsite where kept to a minimum. As a standard AC squirrel cage design would be a much larger 355 Frame unit rather than a 200 frame which the equivalent ABB Square frame utilised.

Motor selected was as follows:

• Type code: M3EH 200E 4, High dynamic performance motors
• 262.30kW, 2000r/min, 400V, Y/D, 50Hz, 0.000A, cos. phi 0.000, TCLF, 40°C, 1000m IEC, IP23, IMB35/IM2001, IC06, ICLF Complete with
• +037 Roller bearing at D-end.
• +645 Fan motor voltage and frequency.400V/50Hz
• +070 Special shaft extension at D-End, standard shaft material

The customer needed reliability and reduced maintenance commitment so with that in mind we selected the high performance Danfoss Vacon 100 Cabinet built drive 460 Amp complete with safe torque off card, with both Manual and Auto control configuration.

JJ Loughran had an 18-Hour window to remove the defective DC bull motor and Control techniques drive and reinstall the new AC solution.

Due to limited space and access in the fan room where the motor was located, we could not utilise a tradition forklift, therefore our engineers had to utilise our own 2 tonne Reid aluminium gantry. JJ Loughran were also responsible for integrating all drives controls to work in conjunction with the EFCO furnace PLC.

JJ Loughran was the primary contractor and designer for all the works which included mechanical, electrical and control works as well as laser alignment of the new complete drive train.