Efficiancy in Focus Case Study

POLYPHAZ High efficiency rotary converter Case Study Lake Toolibin Narrogin Western Australia

We are often asked about power consumption of our converters, efficiency, voltage asymmetry, current balance, etc. so we thought the best way to put the point across was to use a actual case study of a unit that has been in use for some years ( install date 1994), running continuously to operate 2 x 7.5kw compressors & 1 x 7.5kw pump and AIRWELL pumps

These readings were taken when the converter was approx. 60% loaded & what is worth mentioning is that the similar readings in voltage, current asymmetry, & efficiency were taken though out the load spectrum

How we achieved these results:

  • Four stage VolTrak system, that ensures high efficiency through good voltage asymmetry though out the load spectrum.
  • Floating pole rotaries ( FPRs ) coupled with modified rotors ensure:
    1)High efficiency
    2)Low circulating currents
    3)Lower power costs
    4) Low harmonics… throughout the load spectrum
    5) High power factor
  • NO high speed electronic switching devices used or uncontrolled diode bridge rectifier used in the output power supply.

Incoming power to POLYPHAZ converter under load

Voltage single phase : 480 volt
L1- 39.4 amps
L2- 39.0 amps

Output power from POLYPHAZ converter under load

Voltage three phase
L1 > L3 – 415 volts
L1 > L2 – 420 volts
L2 > L3 – 419 volts
L1 – 26.6
L2 – 24.2
L3 – 24.4


Output voltage asymmetry (voltage balance across phases) 1%
Output current asymmetry ( current balance across phases) 3%
Converter efficiency under load 97%
Power factor 0.99


Automated dairy farm, Mt Gambier South Australia powered by POLYPHAZ single to three phase rotary converter.

This Automated dairy runs 24/7 and as such reliability , easy site fault diagnosis , and low power consumption were all on the top of the list for this type of application.

Installed in Mt Gambier South Australia, this had a high specification with regards to three phase and single phase power output voltage , power consumption / losses, and short circuit fault rating.

“The Polyphaz unit is running very quiet and is much quieter than the small 2.2kW Vacuum pumps that are in the same room as the Polyphaz unit. The Dairy Farmer is very impressed with the unit.” , 15/9/2011


Site test results taken 15/9/2011 , model: R37/480C:

POLYPHAZ converter output three phase voltage: L1 > L2= 418v, L1 > L3= 429v, L2 > L3= 426v

POLYPHAZ converter output single phase voltage: L1 > N = 237v, L2 > N = 244v, L3 > N = 243v.


Load snapshot

Input power consumption: L1: 26amps , L2: 25amps @ 479volts
Input 1 phase watts: W= V x A x P.F= 479 x 25.5 x .99= Watts: 12092.35

Output power consumption: L1: 13amps, L2: 18amps, L3: 16amps , averaged: 15.7amps
Output 3 phase watts: W= V x A x P.F x 1.732 = 424 x 15.7 x .99 x 1.732= Watts: 11414.28

12092.35 – 11414.28 = 678 watts


Results :

3 phase voltage asymmetry: 2%
1 phase voltage asymmetry: 2%
loaded converter losses: 678watts
Efficiency loaded: 95%
unloaded converter consumption: 455 watts
Short circuit fault rating: 25 KA
Power factor 0.99
C-tick approved yes

These results are impressive, particularly the low power consumption from a 37KW or 50HP capacity rotary converter capable of 6 x F.L.C multi motor starting, the end user gets the benifits of a rotary converter without the downside of power consumption, this is achieved by using our unique floating pole rotary’s and maintaining the Power Factor at unity throughout the load spectrum while maintaining a relitively high fault rating of 25 KA.

A high short circuit fault rating is important and often overlooked particular in larger installations like this, for example if a fault accures downstream of the converter and the converter is supplied by say a 100 KVA transformer with a high fault level
a low fault rated converter serves as a expence fuse in the event of a short circuit fault.