We all like living in the country side, small villages and towns etc. but the drawback is the angry electric pixies that we use to drive our electrical equipment are delivered mainly by overhead cables. All these pylons look to the sky and demand to be hit by lightning.
The last couple of months have been quite bad with regards to problems with power cuts and outages. When it’s very windy, the overhead cables can sway and touch, debris can be blown across conductors, causing the local distribution nodes to shut down and reconnect. Lightning can cause all kinds of problems. At least, a lightning strike on overhead cables will electrically “saturate” power transformers, causing a “brownout” of power. i.e. a second or so of no electric. In the worst case, it can destroy all equipment in your property. Most pylon networks are linked together at the top with a cable called a longitudinal earth. This cable travels the length of pylon routes. The idea here is that should lightning hit a pylon, the energy is discharged to ground via many pylons, over tens of kilometers, minimising local damage.
Almost every electronic piece of kit we have in the home has some very sensitive circuitry with more computing power than the whole of the UK had in the 1960s. All this stuff runs at very low voltages and currents and can be confused or trashed by a lightning “spike”. I see many a household item needing repair as a result of this. TV sets, satellite boxes, PCs, routers, fridges, sound systems….it goes on.
The short power breaks we get can cause real damage to equipment. The glitch can cause corruption of the computer controlled insides or damage the internal power supplies. A UPS (uninterruptible power supply) can help minimise damage.
This is a box that sits between the power supply socket in your house and your equipment to be protected. Two types; OFF LINE. This UPS in normal conditions, connects your equipment directly to the power in your house, as if nothing was happening. However, when a short power stoppage occurs, it quickly switches in it’s internal battery which operates a circuit to provide synthesised power to your equipment. The long and short, whatever you have connected to it continues to run without problems. The changeover takes some 10ths of a second. When normal power is restored, the box reconnects you to the mains and then recharges it’s battery ready for the next interruption. Jolly good. The other type is an ON LINE. Here we have a unit which provides a synthesised power all the time, irrespective of power cuts. What you are connected to is not a mains power from the network, but locally generated. It provides a far greater isolation between you and the outside world of mains supply. These systems are favoured by data centres and communications networks and iron lung machines. But, at 4 or 5 times the price of the OFF LINE kit, your choice.
Before buying a UPS, there are a few things you must consider. The amount of power you require to use, the amount of time you want the equipment to operate in the event of power cut and lastly, the type of items you need to protect.
The “power requirement” could be small, 150 Watts, for a small TV and a sky Box let’s say. A large OLED TV and other bits and bobs would draw more power. The “runtime” the UPS indicates how long it will operate for in case of a mains outage and determines the capacity of the internal batteries required. Another thing is how much power is required when your piece of equipment initially starts up, we call this inrush current. Let’s say that you have a power cut and you want to turn on your TV. The TV will demand some 3-6 times more energy than it consumes when operating normally, for a split second. A standard UPS will cope with that. However some bigger items with bulking power supplies like big home cinema systems will have a massive inrush demand, which may cause the UPS to shut down. Items such as pellet burners should be protected, but these require different amounts of power depending on their working cycle. So I always suggest a UPS with a higher capacity than normal.
Other things to consider when looking at a UPS, is the type of equipment you want to connect to it and what the equipment has inside it. If you have a heating system with electric pumps etc. these like to see a nice clean Sine Wave of power. Budget UPSs tend to generate a rather crude rough output and can stress induction motor pumps, making them sad and unhappy. The power rating of a UPS is normally stated in Watts and VA, example being 1000 Watts, 650VA. Now Volts x Amps should equal Watts, but due to the reactive element of the equipment connected, there is a sort of loss. Don’t worry, take the lower figure. I can help with all of the above in guiding you to what you need. Just give me a shout. Or phone call if easier.
Whilst scribbling, the other thing that you may be well minded to have fitted to your consumer unit, is a set of over voltage safety fuses. These will help protect your household from mains surges, lightning and incorrect voltages when the electric company’s engineer incorrectly reconnects your supply after a good lunch. Again, give me a call and I can advise. Stay safe. Seth, Zeta Services, working hard.…for you.