In this real-life case study, Zack Hartley, Technical & Applications Engineer at Chauvin Arnoux UK, recounts how the PEL103 offered a ‘Pearl of Wisdom’ to Astral Electrical.
Pearl Window Systems of Bolton recently had an issue with its incoming supply after the fitment of a new 3-phase electricity meter and significantly reduced capacity main fuses by the DNO. Concerned that this could potentially jeopardise the smooth running of its facility, the company reached out to Astral Electrical for help.
The original incoming supply was fused at 100amps per phase, and Pearl had been operating on that supply for 25 years without any issues or incidents. That was until the DNO sent somebody to fit a new electricity meter!
Shortly after fitment the customer noticed an increasing discolouration of the plastic meter housing where one of the tails entered, and promptly phoned to report the finding.
The DNO sent an Engineer out to investigate, who quickly fixed the issue, revealing that one of the phase conductor terminations hadn’t been torqued down properly. However, while they were there, the Engineer also advised Pearl that according to the DNO records the supply was supposed to be fused at 60 A per phase, and promptly changed out the fuses.
Concerned that the reduced capacity supply wouldn’t be big enough for the multitude of loads in its 80,000 square foot facility, and not wanting to experience any supply disruption, Pearl contacted Allan Duckworth of Astral Electrical Services to come in and perform a maximum demand survey.
Allan set about hiring a Chauvin Arnoux PEL103 Power & Energy Logger, and once he had received it, contacted the CA UK office to seek help in connecting and setting up the instrument.
In-person visit
Allan expected to be pushed towards an explainer video or talked through the process on the phone, but since it was only a 40-mile drive across the Pennines from the CA offices to Westhoughton, I jumped into a car and headed over.
The moment the PEL103 was connected to the installation currents of up to 65 A were seen on the instrument display. These were being drawn on all 3-phases, and obviously slightly exceeded the rating of the cut-out device.
However, as that was just a snapshot in time and Pearl needed to see what happened over the course of a normal manufacturing week, the PEL103 was set up and left to log for seven days to determine the actual maximum demand of the installation.
The requirement was to just log current consumption, and so no voltage connections were made which meant no exposure to live circuits was necessary, just the simple looping of the flexible current sensors around the meter tails.
The following week the PEL was disconnected and the data downloaded into the analysis software where the one-minute aggregated data showed average currents up to 67.59 A had been drawn, as shown in the first graph (Fig 1). However, switching in the Min/Max data which includes one second measurements, as shown in the second graph (Fig 2), revealed shorter duration currents of up to 142.4 A had been drawn.
Zooming in on some of those events showed high current durations of several seconds (Fig 3). These were most likely due to motor inrush currents that occurred during equipment startup or other similar surges. One particular event is pictured that occurred for just six seconds.
Armed with the seven-day current log information Pearl Windows re-contacted the DNO to advise them of their findings and submitted the PEL report as supporting evidence. To everyone’s relief the DNO contacted Pearl shortly afterwards and arranged to attend to install a new 125 A 3-phase supply, for which there was no charge.
This is one of a growing number of cases where Power & Energy Loggers, capable of producing the necessary accurate and credible measurements required to convince DNOs, have done just that.
Whether you need to measure maximum demand, out of limits voltage excursions, issues with harmonics, or a multitude of other mains supply parameters, Chauvin Arnoux PELs have you covered.
Visit the Chauvin Arnoux PEL103 product information page here
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