Powerpoint Engineering were called to investigate electrical power quality issues in November 2019 at a meat factory in Cork.
It was found on site that the automatic Power Factor Correction (PFC) equipment was overheating and had a history of repeated failures of capacitors and switching contactors.
Some components were replaced and maintenance was performed on the equipment. It was found that the PFC bank was constantly running at full capacity, and under-dimensioned for the site electrical load. A report was issued to the client that the equipment was at end of life and should be replaced.
In February 2020, the equipment finally failed, beyond repair.
At this time it was decided by the factory to replace the equipment. New equipment was dimensioned (Electrically and physically) from the previous maintenance report. A turnkey offer was made to the client for supply, installation and commissioning of the new equipment. The factory ordered the equipment in late March. The equipment was supplied in mid-April, installed and commissioned the same week.
During the 8 week period while the PFC was inactive, the factory bore electrical utility bill penalties of almost €2,000 per month for ‘Bad Power Factor’ charges.
At commissioning, it was noted that there were Panel Mounted Energy meters installed on the incoming supplies. It could be seen that the connected load had > 440kVAr of Watt-less Power component. Once the PFC unit was commissioned and switched on, this Watt-less Power was reduced to 40kVAr and the site power factor was corrected to 0.99 lag. This now has the benefit of eliminating the utility bill of ‘Bad Power Factor’ charges and also the MIC/kVA demand is reduced.
Pay-back/Return on investment calculations were made very easy, with a utility bill reduction of €2,000 per month.
Electric Ireland have an explanation of Watt-less charges on their website at: https://www.electricireland.ie/business/help/efficiency/wattless-charges-for-business—explained.
‘If the number of wattless units you use in a single billing period exceeds a limit of one-third of all your general units (both day and night), then a charge will apply.’ (www.electricireland.ie April 2020)