AC versus DC motors / drives

While there are hardly differences between AC and DC drives regarding controllability, AC drives offer additional advantages and cost savings in the medium to long run. Therefore, Cincinnati Extrusion now offers AC drives as standard. Please see below for more information.

In comparison to DC motors, AC motors:

  • are simple: AC motors are asynchronous motors (ASM) and therefore mechanically simple, requiring no inner maintenance at all, except occasional greasing of bearings; no changing of brushes, no cleaning of inside necessary anymore
  • have higher energy efficiency across the whole speed range, i.e. their energy consumption and heat loss especially in the part-load range are minimized
  • are subject to less intrinsic heating, which means smaller cooling fans and lower noise
  • are less expensive

In comparison to DC drives, AC drives (frequency converters):

  • are quite insensitive to the quality of the mains supply, as frequency may vary between 45-65 Hz. Net disruptions and harmonic waves become negligible for operation - therefore using e.g. an emergency back-up generator to power the extruder is possible without special adaptions and alterations
  • are available in a water-cooled version from 75 kW upwards, allowing closed electrical cabinets without dusty air cooling depending on lower ambient air temperature, thus prolonging the service life of electronic components
  • are more expensive

Savings with Talos extruders

In intense negotiations and with continuous developments, Cincinnati Extrusion has ensured that our AC drives / motors are as well-priced as possible. The slight rise in extruder price is offset in the medium/long run by substantial savings for our customers.

  Costs for carbon brushes* (Euro) Additional energy costs
for DCs at partial load
operation+ (Euro)		 Total cost savings (Euro)
Talos 45 6,560 plus unplanned downtime 16,200 22,760
Talos 60 6,560 plus unplanned downtime 17,000 23,560
Talos 75 9,960 plus unplanned downtime 25,000 34,960
Talos 90 9,960 plus unplanned downtime 38,000 47,960
Talos 120 12,760 plus unplanned downtime 51,000 63,760
Talos 150 12,760 plus unplanned downtime 67,000 79,760

* Calculated with spare part costs for brushes over 5 years (assuming approximately 3,000 hours lifetime of carbon brush kit, 2 hours' service costs at € 78,00/hr; please add your costs for 1 hour unplanned downtime.

+ Basis: 5 years = 30,000 hours; 30% = 9,000 hours in partial load operation (50%); costs for 1 kWh = € 0.10.

Calculations have been made with DC motors having 20-30% higher energy consumption at 50% partial load.

Savings with Monos extruders

In intense negotiations and with continuous developments, Cincinnati Extrusion has ensured that our AC drives / motors are as well-priced as possible. The slight rise in extruder price is offset in the medium/long run by substantial savings for our customers.

  Costs for carbon brushes* (Euro) Additional energy costs
for DCs at partial load
operation+ (Euro)		 Total cost savings (Euro)
Monos 45 6,560 plus unplanned downtime 21,500 28,060
Monos 60 9,960 plus unplanned downtime 29,000 38,960
Monos 75 9,960 plus unplanned downtime 54,000 63,960
Monos 90 12,760 plus unplanned downtime 71,000 83,760
Monos 120 12,760 plus unplanned downtime 79,000 91,760
Monos 150 12,760 plus unplanned downtime 99,000 111,760

* Calculated with spare part costs for brushes over 5 years (assuming approximately 3,000 hours lifetime of carbon brush kit, 2 hours' service costs at € 78,00/hr; please add your costs for 1 hour unplanned downtime.

+ Basis: 5 years = 30,000 hours; 30% = 9,000 hours in partial load operation (50%); costs for 1 kWh = € 0.10.

Calculations have been made with DC motors having 20-30% higher energy consumption at 50% partial load.