"Theory can only theoretically explain what happens -
What has become apparent is what was intended to be used in the home is now almost common place on each and every work desk, this being the personal computer. No longer is it just a simple terminal fed into a large mainframe i.e. one device. It is now a CPU, monitor, and printer, not counting other peripherals such as scanners etc., and each of these fitted with a modern day "efficient" switched mode power supply (SMPS) as opposed to the good ol' fashioned linear regulator.
As if this was not bad enough, households are now bombarded with using "Energy Saving" devices such as low-wattage fluorescent globes instead of standard incandescent ones. Another modern household feature is "low-voltage lighting", also using a SMPS (the word "transformer" is misleading). It does not take long to have a household running almost exclusively as "hi-tech, energy saving". As a result the workplace is not the only one contributing to the non-linear, non-resistive load of modern technology but also the modern-day household meaning the distribution networks never get a rest from this.
There appears to be a general problem with the definition of 'symptom' and 'cause'. The cause is the reason a symptom is visible. The symptom could be a wire is getting hot however the cause may be a number of things e.g. the current is too high, or the wire is near a bad joint. Distinguishing symptom from cause is vital in tracing power quality issues.
In the previous section it may have been noticed that reasons were given for certain symptoms developing. If one were analyse the reason it will be noticed that the reason itself was still a symptom. An example of this is voltage being out of spec. The fact it is actually so points to other reasons meaning the voltage issue is still a symptom. Got the idea?
Causes can, as with symptoms, be put into general catagories. Before we tackle the issues at hand, it is important to understand the way the supply is delivered from the network to the final point and is covered in "Types of Network Connection". Knowing how the power is delivered to the premises goes a long way to understanding how the fault could develop.
Once we have the types of connections mastered we need to understand "phase rotation" and how this could impact our understanding of faults. "Phase Rotation" deals with the misunderstanding that can surround the sequence of a 3-phase supply.
Once done we then move to the "Issues" and cover the general areas of concern in power quality.