Getting power supply right for security needs
Security systems are only as good as their weakest link
Ian Moore, Managing Director of Elmdene, stresses that it is important not to overlook power supply units for security systems being used in the construction sector for site security and offers some critical advice on the key features that purchasers should be looking out for to ensure that the solutions adopted are actually fit-for-purpose.
While attention is lavished on the specification of more visible elements of a security solution, like CCTV cameras, DVRs, intruder and alarm systems, to keep sites secure and running smoothly, across the Middle East this is still a far cry from that given to mission-critical PSUs (Power Supply Units).
In fact PSUs are often left out in the cold as the poor relations, thrown into the mix at the very end. In my view, this really makes little sense given that security systems are only as good as their weakest link.
Drawing an analogy with a motor vehicle you wouldn't leave the amount of petrol in your tank to chance before setting out on a critical journey so why take a haphazard approach to security system power supplies?
So what are the searching questions that you should be asking providers to help to identify the right power supply unit for your construction site security needs?
A Question of Voltage
One vital area to clarify with a power supply vendor is whether the unit you are considering purchasing can actually cope with the input voltage specific to a construction project's location, whether that be from the mains, a conventional generator or solar power. The reality is that country-to-country across the Middle East the voltage can be anywhere from 110V - like in Saudi Arabia - to 220V, 240V and even 250V. Some sub-standard models on the market are not designed to take account of these regional variations. For our part at Elmdene we have created switch mode PSU models that can work, comfortably, with anything from 90V to 260V. So what are the implications if your PSU cannot do this? Well, at the most basic if you have 240V going into a 110V device it is liable to blow all of the fuses. In the case of supplying 110V into a 240V device you will in all likelihood not achieve the output that you need to make it work at all.
Turning to a related issue, it is important to check that PSU models are tolerant of input voltage fluctuations which, if left unchecked, can result in problematic 'brownouts'. Inferior linear style PSUs struggle here as what you put in is basically a ratio of what you get out. If you constantly raise and lower the voltage most of today's electronic security and fire equipment, which works to very small tolerances, is liable to be damaged. In a location where power generation may vary 10 or 20 percent, either side of the optimum level, the upshot is that you want power supply units that can handle variable inputs and still maintain a standard output. This type of capability is certainly advantageous where systems are being run off generators which is typical of many new build construction sites.
The efficiency of a PSU is becoming an increasingly pivotal consideration, even in the Middle East where energy is so readily available. To achieve better operational efficiencies you really need to be thinking about models built around switch mode technology rather than the more traditional linear PSUs. When deployed, for example, because of the way they are designed, switch mode units offer a significantly higher level of efficiency, typically 80-87% and, correspondingly, lower energy bills and a reduced carbon footprint to protect the environment. Also, at a practical level in the Middle East if some security systems are being used in remote construction site locations where you only have solar power then you want the most efficient equipment you can get hold of to maximise the benefit of the power you are able to generate.
Where you are seeking to put a PSU unit into a confined space then, naturally, you should be focusing on the type of PSU that is more compact. Switch mode models score highly here as the latest are, typically, significantly smaller and a tenth of the weight of old linear style - copper-based - units.
Another factor, when it comes to PSUs, to press your supplier on is what temperature the unit is going to operate at. It should be remembered that switch mode power supplies, due to their heightened efficiency, operate significantly cooler than established designs. This is underlined by the fact that older linear units are hot to the touch and are, consequently, more susceptible to failure. This is even more of a factor in high ambient temperature environments and cooler running can, potentially, support extended product life in the field.
On another note, for critical applications like fire systems it is important to establish if that there is actually monitoring of the circuits in your power supply, and the battery conditions, and that this is reported to the panel with an output to another system to provide an alert should an issue emerge. In the construction environment where refurbishment projects are concerned the threat of fire is all too real.
It is also vital to confirm that any PSU you select is compliant to recognised codes for your area. The appropriate standards vary widely from country to country. In addition, it makes sense to ask about the level of technical support provided by your vendor and, for speed of delivery, whether stock is actually held locally in the region.
No Power - No System
So to conclude, the message to prospective purchasers of PSUs to work with their construction site security infrastructure, from CCTV to access control systems, is that it makes sense to take time out and check on the suitability of a specific power supply unit rather than simply throwing something in, crossing your fingers, and hoping it will work. The right solution can make a concrete difference to the operational efficiency and reliability of security and fire solutions, whereas, by the same token, the wrong choice can lead to the prospect of unexpected downtime, with no power for CCTV cameras or recording devices, and serious gaps in capability when you are looking to protect valuable materials, plant and equipment.