UPS/Inverter

I hope you find something that works. I am sure our friends in South Africa are looking hard for the same thing as they are having the same problems.

As Steve has said, we are also frantically desperately looking for good solutions.

For interest sake the mines in SA decided to abort underground operations because it is not safe enough. They are about to lose a lot.

Just out of curiosity, Who owns or control the power co in Nepal?

Did the government system changed drastically in the past 15 years? Was Nepal ever a British colony or controlled by it? (Is there a pattern somewhere?)

I think a UPS was designed for short power interruptions and not for prolonged periods.

Would it not be better to run a computer directly on external batteries ? (without inverting it to AC to be immediately rectified to DC again.) What do CR4 EE's think. (The CRT should be replaced with a low powered LCD etc.)

Now a days solar Backed UPS is available which should reduce running cost.Standard UPS battery backed is available at varying levels of price depending upon the quality, Brand etc.If You are looking for lower initial investment try assembled units.

I am sorry I missed the 11 hours condition.I too will be happy to know a solution for this.

1.5KVA UPS can be configured with auxiliary battery charger and a bank of batteries to support the load for 11 hours. The problem is the cost and charging time for the batteries get ready for next power outage.

Best solution: UPS 1.5KVA w 15 minute battery and electical generator -Honda or similar- rated at minimum of 3KVA. Make sure Generator output frquency 50/60Hz +/- 2%, that is to sync with UPS .

1500KVA is a lot of power. Any chance you can reduce the load to just really essential electric demand? Can you use alternatives for lights. Are these rolling blackouts related to China's problem in getting sufficient coal for their power stations?

Unless you find an independent power source locally, such as methane digesters or vegetable oil fuel substitutes to produce fuel for a small generator, any solution will be expensive. The inverter part is easy and low cost. The batteries will be large and heavy. The lead alone is an expensive raw material due to demand. Photo voltaics are even more expensive. If your location in Nepal is windy, wind generators may be the best solution for generating and storing power for use during black outs. It might also reduce the size of battery bank required.

Hi Elnav

i think it is 1.5 KVA he is looking for.

Right! delete the "K"

My original question was about needing 1500 watts for just a home or office computer. Most single station computers plus printer only need 300 wats or so. But if its a case of many computers plus other equipment and illumination for the whole building, then yes a generator is perhaps the better solution.

This brings up a very relevant issue of running costs. Diesel or gasoline fuel is expensive. I did not see an answer to my quetion of whether the Nepal electricity shortage was related to reports of Chinese power production suffering from a shortage of coal and othr fossil fuels for their big utility generators.

If the rolling black outs are in fact related to a national energy crisis then any short term solution will also suffer from the same causes. Diesel or gasoline may not be available to consumers in unrestricted quantity. In most countries suffering a national fuel shortange , all supplies of fuel tend to become rationed and allocated acording to some priority.

In which case only solar or wind charging equipment would not be limited by rationing. It would however be limited by geographic location as to sunlight hours (latitude) and wind conditions affected by local topography.

will 11 hours be a continuous requirement or totally 11Hrs per day.Because Battery charging is a problem.You can think of a gas generator If Gas is Cheap i mean LNG Or LPG.Gobar gas is another alternative but needs environment maintenance and some civil works.Actually there is a system which ensures Bio wastage such left over vegetables (Except the citric Type) which is used to generate Gas for Cooking .I feel Same can be used for use with small generators also.1.5KVA bio gas generator may be a cheap alternative with auto transfer arrangement may be a solution.Entire gas plant is supplied and Installed.

I was very impressed with CHtank's post in this thread..

Composting-Horse-Manure

Seems to me that animal waste is being "wasted" all over the world when it could be contributing to power needs. I think this makes more sense than straight up bio fuel..

There is an inverter i came across. In SA it is very expensive but you can shop around and maybe you can get one for cheaper. At least you will get an idea what to look for, It is a pass-through inverter, various wattages are available on the market. This would be for long term sollution. Just browse on the net for, XPC-1400-12 (1400W/12V - built in charger 45A) / or XPC-2200-24 (2200W/24V - built in charger 37A) / HPC 4400-24-100 (4400W/24V - built in charger 100A / HPC 6000-48-70 (6000W/48V - built in charger 70A) / HPC 8000-48-90 (8000W/48V - built in charger 90A). How these inverter work is this. With the power from your supplier on, the charger trickle charges the battery's to keep them at full capacity. You are not running anything off battery at this stage (pass through). You are using your supplier's electricity. As soon as the power is cut from your supplier the inverter switches over to battery power and will feed the emergency wired circuit. The nice thing about this inverter is that you can also connect a generator to it for recharge or even solar. All the input's are already there.

Pending the amount of wattage you want to use and the time you need to use the inverter would determine what to buy. For instance, 1400W/12V with 4 x 12V/102Ah battery's will only give you about 120 minutes usage. More battery's are then needed. It will also take a lot of time to recharge the battery's if used till they are exhausted.

For the price of purchasing all the inverter, battery's, charger, installation ect... maybe you should look at a small generator. Only problem with generator is that you look at fuel cost and service cost.

REMENBER: Electricity kills, only wire it if you know EXACTLY what you are doing, otherwise let a qualified person install it for you.

Hope this helps

Hi,

This is not a good application for a ups and in the long run you will be better off getting a generator to provide the 11 hour up time and only use the UPS to prower the load when the generator is starting up or being refueled. The reasons are as follows:

1) The battery discharge to recharge rate is typically 10 times the discharge rate to get back to 95% charge.

2) Because of the length of time you want to cover you will need to go with a larger ups system with a bigger battery circuit. The larger battery circuit should have more battreies which results in a longer run time and a larger capacity charger to recharge the batteries faster.

3) Because of how much the batteries will be used the life of the batteries will be very short and require frequent replacement, ups's that size use VRLA batteries that have a life of 3-5 years, the way you will be using them you will be lucky to get 6-8 months from the batteries.

Because of the reasons listed above of the life of the project the generator with minimal ups backup of the load is the way to go.

Figure out how many batteries you need for 11 hours run time. (hopefully this is not an everyday event). (I estimate perhaps 45 min @ 750 watts using one battery ---> 22.5 min at 1500 watts 'maybe' then you need quite a few? 33? ) This is equivalent to running a space heater on full blast (1500 watt type). Use 1500 watt inverter with the batteries charged from grid current.

Or check internet for solar cells if you can't do that or can't charge from walls. Use solar to supplement lesser $ and less number of batteris. You can find 45 solar watts for $200 if you look hard enough with controller, lights, plug ins, etc.