Power Quality – What is it and who needs it?
Only the most modern power quality analysers are used. Sampling the waveforms on each of the 8 input channels at a rate of over 12000 times per second leaves no room for error.
There are many technical definitions of Power Quality. However a plain English definition of Power Quality is: The attributes of electricity supply that when correct, ensures optimum and efficient operation of all electrical and electronic equipment.
The consequences of poor power quality (or dirty power) for electrical and electronic equipment often includes the following:
Equipment tripping out (shutting down) unexpectedly, causing production delays and rework.
Equipment failing prematurely or just not lasting as long as it should, increasing costs to the business.
Equipment running hotter than it should and therefore wasting energy, and likewise increasing business costs.
Some of the consequences of poor power quality, such as equipment tripping out when it shouldn’t, can be very obvious and draw the business owners’ attention to the issue. However, sometimes the consequences of poor power quality can go by undetected for years; but all the while increasing business costs by reducing life of plant or causing efficiency of machinery to be low.
In seeking help with power quality issues please be mindful that many businesses who undertake power quality audits and surveys also manufacture or sell equipment. This is a natural link but introduces the strong possibility of vested interest and subjective analysis – as their end game is to sell you equipment. As Barry Kennedy says in his classic book Power Quality Primer, “Electrical vendors and contractors provide useful information on the installation of equipment but should not perform the power quality survey. The power quality consultant needs to perform the survey in an objective and unbiased manner and not try to sell a particular product….”
At Power Quality Investigations we provide a professional, unbiased and objective service and are not trying to sell any equipment. In addition, if the power quality investigation reveals that you may benefit form equipment to improve your power quality then we can provide an independent service to help you get competitive quotes from several of the quality suppliers in the market, thereby ensuring you get the best value for money and that you not sold something that you don’t need.
At Power Quality Investigations we use modern sophisticated power monitoring equipment and pride ourselves on doing a detailed analysis, yet provide the client with an easy to understand plan English report. The findings are clearly laid out, as well as the recommended next step or suggestions for remedial actions. All the really technical information that should be kept on record is included in comprehensive appendices to the main report.
If you have issues with your power quality, or simply require a power quality audit for peace of mind, then the professional staff at Power Quality Investigations can help you.
Demand & Load Loggings – What is it and who needs it?
Power Quality Investigations offers a full service for providing recordings of Maximum Demand and Load Profiles.Typical instances where this information is necessary are:
A commercial or industrial customer is looking to install additional electrical equipment but is unsure what the present maximum loadings are on the main switch-board, or on the relvant sub-board.
The main circuit-breaker is experiencing nuisance tripping and it is unknown whether the circuit-breaker is faulty or if the load is exceeding the maximum allowable.
The customer has an unbalance of load distribution on the three phases and they need detailed load profile information so that their electrician can undertake the rebalancing necessary.
The customer desires load profile information so that they can better understand their electricity usage patterns. Thereby managing their electricity consumption more effectively and by comparing profiles can directly see the benefits of energy efficiency initiatives.
Many commercial and industrial customers pay a Maximum Demand charge as part of their electricity tariff. Yet they do not have information on when the peak demand occurs, nor do they know what equipment or process is contributing to the peak. In short they do not have adequate information to manage the demand charge – which can be significant. A full load profile recording will however provide all the information needed to better manage this cost.
If a customer is considering installing Power Factor Correction (PFC) equipment to reduce their demand charges then a load survey will enable the PFC equipment to be correctly sized from the start.
No matter how big or small the job Power Quality Investigations can provide the service you need. From providing a voltage or current profile for a small commercial or industrial customer, through to providing a comprehensive analysis of load profiles and power quality issues for a large industrial customer.
Check Metering & Bill Verification –
What is it and who needs it?
Normally a customer has to accept at face value that their electricity bill is correct, trust what is being asked and pay the bill.
Errors in electricity bills are not particularly common, but they do now and again occur and the consequences for the customer can be significant. Errors that can arise for industrial or commercial customers is that there is a mix-up in the billing data and the customer gets sent an account for somebody else’s usage, or there is an error in the recorded current-transformer ratio which throws the accuracy way out. (Or shorted turns within the current transformer can also result in an incorrectly high bill – this type of fault is rare though)
If you suspect that there is something wrong with your electricity bill, or if you would simply like peace of mind that it is correct then give us a call. Power Quality Investigations can install a check meter for a period of time and provide you with independent metering data with which to compare your bill. If you do then need to approach your electrical supplier you have some hard evidence at your disposal.
Energy Efficiency – What is it and who needs it?
Energy Efficiency. A service to an electricity customer would not be complete without a thorough knowledge of energy efficiency and energy efficient equipment.In the context of power quality this understanding is particularly important because the decreasing power quality that customers are often experiencing is due, in no small measure, to high energy efficiency modern electronic equipment that tend to distort the voltage waveform (high harmonics). Not to say that this type of equipment should not be used, it very often should definitely be used, but what is needed is a holistic understanding of how such equipment interacts with other equipment and with the power supply.
An example of inadequate consideration could for example be:
Businessman “A” purchases a relatively large Variable Speed Drive (VSD) to use on a commercial extractor fan due to the significant energy savings to be had. However, unbeknown to him the VSD is of poor quality and generates too many harmonics and commutation notches (distorts the voltage waveform) with the result that the process controller for his production line trips intermittently. It takes him three weeks and a lot of lost production to find that the cause of his problem is his new VSD. He throws the VSD in the skip, and never again wants anything more to do with energy efficiency – a bad outcome all around, particularly for him.