Production stoppages bring with them financial losses and in most cases they are down to lack of planning, whether due to a logistics issue, lack of preventive maintenance or many other similar problems. There are numerous obvious and visible causes and also others which are harder to identify.
Poor power supply quality is one of them; you cannot see it and its impact may be as serious as any lack of raw material for your production processes. The technology of the machinery involved in these processes is increasingly sophisticated and delicate while the quality of the voltage waveform is taken for granted in most designs.
Many maintenance managers are called in when a machine stops working properly or just comes to a halt for no apparent reason. From then on the experience of the manager and their team comes into play to spot the fault or to restart the system. It is likely that the system will resume operating without any further incidents, meaning the real problem remains unknown and may crop up again at any time with no apparent cause.
There’s no doubt you are getting swells, dips or interruptions in the power supply, and it may be that the electronic systems’ circuit breakers bring the machinery to a halt to prevent damage which can turn out to be very expensive.
Protecting your system against these kinds of problems may also call for significant investment, yet everything depends on how often you have these problems and the impact they have on your operations.
An initial and much more affordable measure is installing a device which can detect and log those problems. With the information from this device you will be able to address the problem with greater chances of a successful outcome.
As we have seen, it is crucial to have real information about the status of the electricity network in order to be able to detect whether a production stoppage is due to the quality of the power supply. For this purpose, there are network analysers which can help maintenance managers to understand what is going on at any given time in order to make the best decision, either to avoid production stoppages or to mitigate their impact.
To try to make performing this task as easy as possible, Circutor has designed its CVM-A1500A power quality analyser. It will quickly report any network quality incidents which may occur in a facility so that action can be taken straightaway.
This model is certified under the IEC 61000-4-30 standard and detects faults in power supply quality in the waveform from the half cycle (from 10 ms in 50 Hz networks and 8.3 ms in 60 Hz networks), providing complete information to maintenance managers about the problem. By installing several units at key points in the installation you can get a clear idea of when, where and how a power supply quality problem has impacted it.
The CVM-A1500’s user interface and integrated Web server provide easy, convenient and intuitive access to information about any power quality problems identified.
The downside when it comes to analysing network quality has always been the interpretation of data by a specialist engineer. Some installations have quality equipment installed but it is not used because users have difficulty in interpreting its data.
Quality analysers are normally “black boxes” which do not provide information if they are not connected via data interpretation software.
So in addition to needing computer skills to download their data you also have to know about their computer program for interpreting these data. If you additionally combine equipment from several manufacturers, then the task is even trickier.
That’s why Circutor has developed a model featuring browsing by colour screens to provide relevant information for decision making.
The CVM-A1500A analyser shows the ITIC (also CBEMA and SEMIF 47) curve on the screen. With just three clicks on the equipment, any maintenance manager can display the ITIC curve.
This curve shows red triangles each time an event occurs, quickly displaying how many quality events there have been and how damaging they have been for the installation. This means you can swiftly see what kind of problem you are faced with.
If the triangles are in the green zone, this means that there have been events (power surges or voltage drops) which have not harmed the electronic equipment in your facility. However, if the triangles are in the red zone, this will mean a swell which has most likely damaged your electronic equipment. The closer the triangles are to the top left, the more damaging they will be due to their high value and duration. By contrast, if the triangles are in the yellow zone this means that there have been voltage drops. These voltage drops may impact electronic systems leading to rebooting or stoppage due to low voltage.
Just by glancing at this screen, any maintenance manager will know why there might have been a malfunction. Furthermore, if it is repeated regularly, they will have more information to install a system which mitigates the event’s impact thus avoiding production stoppages and hence financial losses.
In addition to the curves we have discussed above, the equipment has an event counter which shows you how many there have been in each phase so you will know whether the problem always comes from the same phase or if it is repeated regularly. To get a closer look, you can use the analyser’s screen to review each event individually and view it in detail. With several clicks on its screen you enter the event and see in which phase it took place, what its voltage percentage is, what voltage there was before the event (this helps you see whether it was a fast event due to switching or a slow one due to overloading), how long it lasted (from the half cycle) and on what date and at what time it occurred. Plus you can always enter the event to see its associated waveform, showing the voltage sinusoid to see exactly when it happened.
Transient associated with a quality event
We have seen how voltage events may bring about production stoppage which leads to financial loss. Furthermore, power supply quality analysers can help us avoid future problems in the installation by checking other relevant parameters.
These devices show harmonic decomposition up to 63, and you can see what level of harmonic load you have in the installation. Harmonics can impact the installation’s performance and also trip a circuit breaker or lead to overheating or malfunction of electronic loads.
Quite often installations have uneven currents in the various phases due to poor load distribution or a subsequent line extension. This effect may lead to current flowing through the neutral wire. In these cases it is essential to measure the current flowing through the neutral conductor to avoid possible insulation failures which can cause breakage that leads to swells, thus damaging components of the installation. Furthermore, if the installation has its own distribution transformer, this may overheat resulting in premature ageing and changing its useful life. To avoid these hazards, the CVM-A1500 network analyser measures neutral current along with any unbalance in voltages and currents and reports any situation that may entail a risk for the installation both onscreen and by email.
The CVM-A1500A analyser has a web server with built-in memory. Any user can access the logged data on a web browser (Internet Explorer, Firefox, Google Chrome, etc.) to monitor all parameters in real time, produce graphs and tables, view quality events and waveforms and extract data easily in Excel without having to be an expert in power supply quality software. Plus the equipment can be integrated with our PowerStudio Energy Management Software (EMS) and can be integrated into a complete network with equipment for usage management to provide an overview of the installation’s entire status.
Access by web browser or PowerStudio software
As we have seen, with the CVM-A1500A power supply quality analyser any user can have complete control of the parameters which may bring about a malfunction in any installation and also check where an electrical fault comes from, whether it be internal or external. By exporting data, maintenance managers can negotiate with the electric utility in case of a stoppage due to poor power supply quality or may even demand guarantees for all machines with anomalous operation as they can check whether the failure is the result of an external cause or due to malfunction of the machine itself.