Does anyone have any suggestions for back-ups in case of a power cut?
The main reason for asking is that I live in a bungalow on the caravan park and now and again, we have problems with the supply, usually the park side but during the summer hols we had a power cut in the area which put the power off for about 8 hours. If I'm at work, it's not so bad as obviously, I live at work, but if it's my day off or I'm away, then it could be a bit more serious.
Does anything exist along the lines of the UPS systems that protect our work computers or am I looking at making something from a transformer, an inverter and some truck batteries??
According to my husband yes it can be done, but depends on the load and how long you needed the back up for, plus if you wanted an automatic or switch on yourself pc back up are designed to last for about 8 minute on full load, however even if you overate the battery back up, with no load it would only last for about 6-8 hours as the inverter draws power from the battery. If this is just for your fish tanks then you are better off with a large leisure battery "lead acid battery" of about 38 AH per hour, connected to an inverter (true 600 watt) and a constant voltage mains charger for the battery.
I guess if you used a leisure battery you'd be better off fitting a solar trickle charger to it just to keep it topped up as it will decharge over time. I brought one off eBay for about £15 and it keeps the electric fence battery charged up over the summer months.
Thanks for the replies. I forgot to mention that it's only needed for the tank. If the power is off for a long time, I'm not too bothered about the thought of eating all the ice cream in the freezer
If I use a leisure battery with an inverter, and possibly a solar panel to keep it topped up, is there any way that I can leave it plugged in to the mains so that it can switch on automatically if the mains fails? We have emergency lights around the caravan park that work like that. Is it possible?
You'd need some sort of throw-over switch, I've seen something that can be fitted to solar systems to automatically turn the system to mains when there isn't enough power in the batteries so I'm guess you'd need something similar. Try Maplin Electronics they have a good website, maybe you'll find something there:
MartynWard wrote: If I use a leisure battery with an inverter, and possibly a solar panel to keep it topped up, is there any way that I can leave it plugged in to the mains so that it can switch on automatically if the mains fails? We have emergency lights around the caravan park that work like that. Is it possible?
Forget about solar as this won't work in our climate, the simplest way is is to run from the battery constantly with the mains supply only keeping the battery charged "this is how online battery back ups work, not the cheep units you get for computers which only work on battery in a mains failure situation" this is the safest form of battery back up
well the UPS system would be ideal if your just running a few 100w load on it and im pretty sure that most switch to backup automatically (whats the point in having to change it over yourself? by the time youve flipped the switch your data on your computer would be lost anyway) and i assume that they trickle charge from the mains so they are always fully charged?
petrol generator is the only true way of supplying energy for any length of time although for short bursts with automatic change over a ups would work only in my profesional opinion they can be pretty unreliable as you only find out the batteries have failed when you need them and by then its too late!
Computer UPS systems are designed to give you enough time to save your data and shut down the computer. This generally gives them <15minutes at normal load. I tend to spend about £3000 on each ups I buy. http://uk.insight.com/apps/productpre ... APC%262713v%3D7%26IS%3Don Power runs through the batteries all the time so there is no change over to the power going to the device.
As you can see from the link, when the power cuts you only have 3.3minutes at full load.
I'll have to admit the maths of working this out from those figure escapes me but if your running 50w of filters and pumps you should get a good couple of hours out of such a device but thats a lot of money and if you can hook up an auto-start generator it should be a lot cheaper!