Posts Tagged ‘Control’
Uninterruptible Power Supplies Alarm Monitoring and Control
Posted by Parkzone Corsair in Power Supply on July 26th, 2010
Uninterruptible power supplies (UPS) are sophisticated, microprocessor-controlled systems, capable of providing a range of alarm notifications and real-time monitoring information at local, network and remote site locations.
This is important because it offers peace of mind and negates the need for ‘warden-type’ manual inspection of power protection equipment. However, monitoring for alarm conditions is required. The beauty of today’s UPS equipment is that it can now be carried out at one location, either centrally in-house or off-site at a specialist UPS monitoring provider. Many leading power protection manufacturers, such as Riello UPS, provide this type of service. It often means an engineer can be on-site and have equipment repaired, checked and running before the client is even aware of a problem.
The decision not to outsource uninterruptible power supply monitoring must be reinforced by the provision of dedicated monitoring personnel in-house whose responsibility it is to monitor and respond to UPS alarms. Failure to act in a timely and appropriate manner will significantly reduce system resilience. Typical examples include failure to notice that a UPS is operating in bypass mode or that there is a failed battery in a battery string (note: a UPS battery string is only as strong as its weakest battery).
The advent of Html capability in the software arena has enabled modern UPS manufacturers to integrate sophisticated onsite and remote monitoring capability within their hardware. In fact, modern systems enable remote 24/7 monitoring (either by the client or at the manufacturer’s facility) of all critical UPS, generator, air-conditioning and fire suppression equipment. As well as alerting system managers to problems as they arise, integration of monitoring functions into existing infrastructures gives businesses valuable early warning of impending power and other equipment failures that actively increases profitable uptime.
Most UPS are available with software packages that monitor mains voltage, UPS load and battery charge as standard, as well as proprietary monitoring and control software, which allows remote interrogation of UPS logs and operating parameters to help diagnose alarms and faults. When instructed to do so, UPS software can remotely perform automated and controlled shutdown of valuable equipment – ensuring hardware protection while freeing personnel for other tasks during power continuity incidents.
Types of alarms include:
Audible Alarms: audible signals are generated from within the UPS or a connected remote status panel and may be coded, using varying lengths of sound, to indicate specific alarm conditions. Audible alarm signals will remain ‘on’ until the condition is rectified or the alarm is acknowledged and silenced.
Visual Alarms: light Emitting Diodes (LEDs) provide a basic form of visual alarm notification. They may be single or multi-coloured and indicate the status of the UPS by employing one of three modes: on, flashing or off.
Some UPS utilise Liquid Crystal Display (LCD) with push-button controls to provide a slightly higher level of visual alarm capability. In this case, the user can scroll through a menu of information (measurements and logs).
The most sophisticated level of visual display is a full front-panel graphic-type, which typically consists of multi-character back-lit lines that display information in alpha, numeric and symbolic formats, either as text, alarm codes, graphics or a combination thereof.
Remote communication can utilise one of several protocols to provide data-exchange between an application and its UPS: serial connection (including RS-232), Simple Network Management Protocol (SNMP), MODBUS/JBUS or Profibus.
A range of UPS monitoring packages are available from UPS suppliers – from simple installation software designed to run on laptops, PCs and PDAs to more sophisticated monitoring and control software that runs on an enterprise server (whether Microsoft Windows, UNIX, Mac, HP and many others) and provides a host of information from UPS operating conditions to WAP availability.
There are two common approaches to monitoring and control by uninterruptible power supply manufacturers: centralised and decentralised. Centralised is where a specified server is used to control the orderly shutdown of the mixed platform network. Decentralised is where each individual server or PC runs its own copy of the monitoring software and controls its own shutdown procedure. The centralised approach is the most straightforward and least expensive to install but it can introduce a single-point-of-failure into the system. Should the control server hang and fail to shutdown the rest of the routine will be disrupted leading to potential data loss and a system-wide crash. With the decentralised approach, if one server or PC fails to shut down, the problem is isolated, thus achieving a higher level of system resilience.
The human instinct upon hearing or seeing an alarm is often to ignore it but planning how to monitor uninterruptible power supplies and associated alarm signals, and conceptualising appropriate responses, is an important aspect of a power continuity plan. If you want to go into it in more detail, there is a whole chapter devoted to it in The Power Protection Guide.
Robin Koffler is the General Manager for Riello UPS Ltd the UK subsidiary of Riello UPS (RPS S.p.A) a leading European manufacturer of Uninterruptible Power Supplies and a co-author with Jason Yates of The Power Protection Guide(ISBN 978-0-9554428-0-3)- available from Amazon.com
Five Things You Need to Know About Control Panel Power Supplies
Posted by Parkzone Corsair in Power Supply on July 13th, 2010
If your business relies on modern, high-speed performance sensors and controllers, you will require a reliable DC power source. Traditional, linear power supplies that relied on transformers to convert to AC input into more manageable DC tend to be large and cumbersome and considerably less efficient than more modern systems. Modern control panel power supplies now come in the form of DIN rail mounted systems, which are far more suitable to the modern workplace.
Compact
DIN control panel power supplies are lightweight and efficient, enabling you to have your control panel power supplies mounted above ground height with very little loss of workspace. This also offers them a higher degree of protection from damage by impact or potential flooding than more traditional, floor mounted linear supplies. Because they are more compact, more units can be mounted on the same tracking, which comes in standard sizes allowing you to interchange units easily.
Efficient
Control panel power supplies are also known as switching power supplies. They convert a DC voltage into a lower, regulated voltage by storing the difference in a magnetic field. This makes them much more efficient, with over 80% efficiency compared to only 50% efficiency from linear power supplies. They also incorporate modern developments in power supply technology, including power factor correction, which limits the harmonic current on the input side of the power supply. This ‘cleans’ up the input current, reducing the peak current demand. As a result, control panel power supplies are much more efficient, saving you money in electricity bills, which for medium size businesses can constitute a considerable annual saving.
Legislation
All power supply units are covered by extensive safety legislation and the most modern control panel power supplies are now the safest on the market. By incorporating overvoltage protection, undervoltage protection and strict current leakage technology into units, they also protect equipment that draws its power supply from the unit by preventing power surges reaching the delicate workings of computers or CNC machinery, for example. The legislation imposed also ensures the safety of the end user in any environment and is an important factor to consider when making initial inquiries about installation.
Application
Control panel power supplies can be used in almost any business environment. They are particularly useful in workshop environments, where multiple machines may have to run off the same circuit but with each machine having its own particular needs and demands. They also work well in office environments, where computer networks can all be run from the same circuit, improving efficiency and reducing running costs. Control panel power supplies are best suited to small or medium sized business environments and are cheap enough to be considered even by start-up companies. Although buying a second-hand system from a web auction site may seem like a good idea and an easy way to save a few pounds, consider that with a second-hand unit you will receive no manufacturer’s guarantee or after-care service from the installation company. There is also the chance that it may not conform to current health and safety legislation.
The next step
If you think that a control panel power supply would be right for your business, you need to calculate your input voltage and frequency, the output voltage, the wattage or power in amperes and the peak loading of the output. Once you have these figures, you can then calculate the power of the DC power supply you will need. Think about how much space you have to mount the system and whether a compact unit will have the capability to cope with the number of outputs needed. Talk to a technical expert who has experience in installing control panel power supplies in commercial environments to help you make an informed choice and select the right power supply system for your business.
Control Panel Power Supplies with Meanwell Direct
Everything you ever wanted to know about control panel power supplies but were afraid to ask
Posted by Parkzone Corsair in Power Supply on July 12th, 2010
Most modern high-speed, high-performance sensors and controllers require a reliable DC power source. Used in commercial applications, traditional, linear power supplies that relied on transformers to convert AC input into more manageable DC output are now being replaced by more compact and efficient switching power supplies.
Control panel power supplies are now taking this technology further, allowing businesses to operate using a DIN system that allows controllable power supply delivery to a range of applications.
Switching power supplies convert a DC voltage into a lower regulated voltage by storing the difference in a magnetic field. Because this removes the need for large coils within the system by incorporating smaller electronic methods of conversion, the size of the control panel power supply is reduced and more energy efficient. Switching power supplies are typically over 80% efficient, compared to 50% efficiency from linear power supplies. They are also light enough to be mounted on a DIN rail, which only the smallest linear supplies are capable of doing.
With modern development in power supply technology, switching power supply units often incorporate more advanced features as standard. Power factor correction (PFC) limits the harmonic current on the input side of the power supply, ‘cleaning’ up the input current which reduces the peak current demand. Overload protection protects the power supply from any damage caused by an abnormal rise in output current, and in turn protects any equipment that may be feeding off the power supply.
Overvoltage protection (OVP) prevents load circuit damage by cutting the power supply output when output voltage rises above 120% of the rated value. If the power supply feedback loop fails, for example, the output voltages could rise to levels that may cause major damage to the entire system. OVP detects this high voltage, shorts the output and causes the supply to shut down, preventing a surge that could be catastrophic.
Undervoltage detection indicates if the output voltage drops below a certain level.
When you’re planning to replace your control panel power supplies, there are a few things you need to consider. Firstly, what applications is the power supply intended for? You will need to know your input voltage and frequency, the output voltage, the wattage or power in amperes and the peak loading of the output. You will then need to calculate the power of the DC power supply you need. If more than one output is required, you will need to carry out a quick calculation to determine the total wattage for the supply by multiplying the voltage by the amperage of each output to calculate the individual wattage and then adding these together to give you your total wattage requirement.
You will also need to check the enclosure style, connections and physical size of the control panel power supply to make sure that it is suitable. A unit that is too large may not be suitable for some DIN rail fittings whereas a compact unit may not have the capability to cope with the number of outputs needed.
Although buying a second-hand unit on a web auction site may seem like a good way to save a few pounds, your control panel power supplies must conform to all safety legislation. Buying from a reputable dealer who offers a selection of approved and certificated units is the only safe and proper option when it comes to buying control panel power supplies.
Finally, consider the application that you wish to apply the control panel power supply to. This can include the power supply life, custom power ratings or mixed voltages. A good power supply will need to be able to cope with every requirement you have without having to work at maximum capacity for prolonged periods of time, which can shorten its lifespan. Talking to a technical expert who has experience in fitting control panel power supplies into commercial environments will give you more information and help you make an informed choice when it comes to selecting your power supply requirements.
Keith Finley sent the article on control panel power supplies . Know more about Control Panel power supplies here.
