Microsoft Word 2012, Källén, M.,-Energy Efficiency Opportunities within the Heat Treatment Industry

4.1  Electricity Measurements 

To obtain the electricity consumption of the individual equipment in the plant, the electricity 

was first measured instantaneously and then logged for one week. The electricity distribution 

in the plant consists of a three phase system and the instantaneous measurements were done to 

check if the phases were behaving identically. If there were no differences between the 

phases, either one of them could be logged. If the phases differed from each other, the phase 

closest to the mean behaviour was logged. The principle voltage and the power factor were 

only measured instantaneously. 

Since there was a limited number of ampere meters available, not all equipment could be 

measured. Using the values for the measured equipment and information about operating 

routines, the electricity consumption of the remaining equipment could be estimated, see 

appendix B. The electricity consumption for lighting was calculated with the known power of 

the armature. 

The utilization ratio and the specific electricity consumption were calculated for the 

equipment that had available holding time data. The utilization ratio was defined as the time 

the equipment was used divided by the total measured time. The specific electricity 

consumption was calculated both as electricity consumption per holding time and electricity 

consumption per amount heat treated goods.