A fierce legal battle has ensued down under, with regard to whose fault it is, when equipment is damaged due to poor power quality. Is it the billing provider? Is it the grid company? Or should the customer just have known better?
Ok, maybe it’s not that fierce but an interesting article nevertheless, although it’s written by lawyers so you need to go over it several times to have a clue what’s it’s all about. You can read it here.
Well, it looks like the answer they’ve come to in NZ is that it depends, but it looks like the retailers will be educating their customers on the benefits of surge suppression and Uninterruptible Power Supplies. About time too.
I was reading this article by A.N. Other UPS Company, who state “power protection should always begin with a power quality review to analyse the actually [sic] quality of mains supply and the level required” (Feel free to read it yourselves: http://plumbingsupplie-s.com/947024-Uninterruptible-Power-Supplies-UK.html ), and I thought “Why?”
Why do you need a power quality survey? It may be that you have poor power and so a power quality survey will show you this. So, you’re experiencing problems, you suspect power quality is the reason, a chap arrives with some gadgets and then tells you that you have a problem. OK, so far insomuch as you’ve confirmed that power is, or just may be, the cause of your problems.
What if the survey shows nothing wrong with your power? What then? Do you go searching for other causes? Or perhaps the power quality problems you have didn’t manifest themselves during the survey?
I bet I can predict without turning up at anybody’s premises whether or not they have good clean power. Here’s some rules. The further you are away from the substation, the worse your power quality will be. The more equipment there is on the same network, the worse your power quality will be. If you’re in a rural location, supplied by overhead cables your power quality is probably terrible. This is simply to do with impedance and current. Of course, conversely you can get good clean power if you’re close to the substation with minimal loading on the network. But what about during a thunder storm? Or during utility grid switching? Or during a fault?
The point is, a survey may reveal problems with your power. Whether or not these power quality issues have anything to do with the problems you experience is another question. However, there are also a multitude of power disturbances that may not be detected at a survey but can cause devastation to your systems. So, if any of your electrical/electronic systems are of value to your business, it’s wise to protect them from any eventuality in any case. Protect them with an online double conversion Uninterruptible Power Supply and you’re done.
Simples.
I’ve recently read a quite comprehensive report by the Leonardo Energy Power Quality Initiative Team, that put the costs of poor power quality in Europe at €150bn, a quite staggering figure.
Not all the costs are due to obvious power quality issues, such as blackouts, in fact, short term interruptions were the main culprit, followed by transients and surges – then blackouts. A rising phenomenon is flicker, and the costs borne here aren’t equipment damage, but rather the effects on individuals working in an environment that is prone to flicker. It’s interesting I find, as mostly power quality cost are put in the “data lost cost” and “hardware costs”, but seldom are people included in the equations.
Flicker is caused by changes in the supply waveform amplitude and is noticeable particularly with CRT’s and lighting. Workers subject to environments where flicker is a problem, complain of headaches, eyestrain and fatigue. What’s more, a lot of people are completely unaware that they have a problem.
Flicker frequencies are relatively low, but fast enough to mean that a line interactive UPS can do nothing about them. In fact, the transformer in a line interactive system may make flicker even worse. The only way to cure flicker, is either to remove equipment that is causing the flicker, remove the equipment that is showing the flicker, or fit an online double conversion UPS system. This will provide smooth power to the systems, eliminating flicker, and of course, protecting against all other power anomalies along the way.