Your PEL will, however, give you accurate information about the harmonics in your supply system, once again logging this information over a period of time, if you wish. This is useful before you install the charge point to let you know whether you’re already approaching the prescribed harmonics limit, and after you’ve installed it, to ensure that you are still meeting your supply company’s requirements.
This is not, by the way, just the supply company being picky. Excess harmonics in your supply system can cause heating and vibration in motors, heating in neutral conductors, poor performance of electronic devices, and many other problems that will end up costing you money. This means that you too will have a vested interested in making sure that harmonic levels are low and stay that way.
Finally, let’s consider load balancing. If you have a three-phase supply and you’re installing three-phase charge points, this shouldn’t be an issue, but what about if you have a three-phase supply and you’re installing single-phase charge points? This can be problematic because even if you’re installing them in multiples of three and distributing them across the phases, there’s no guarantee that they will all be in use at the same time. The upshot is that with single-phase chargers, there’s always a risk that they will unbalance your supply.
This is a particular problem if your business uses three-phase motors, because an unbalanced supply will cause them to run badly, with excess vibration, and to operate inefficiently using more energy than they should ,which will cost you money. In tackling this issue, the PEL is once again your friend. It will let you see how well your phases are balanced – and don’t forget you’ll need to check this when the chargers are in use and when they’re not. It will also help you to see the effect of redistributing your existing loads to provide the best balancing possible.
As we’ve seen, a PEL is a very useful asset when planning EV charge point installation, and also after the installation is complete to verify that the loading, the harmonics and the supply balance really are within expected limits. Is it worth buying a PEL for this? Only you can decide, but it could easily save you much more than its purchase price, especially when you remember its ongoing usefulness. Quite apart from any consideration of the EV charge points, regularly monitoring your supply system to check for balance, level of harmonics, unexpected out-of-hours usage and power factor can save you a small fortune. A PEL is not just for now – it’s truly a friend for life!