Rural Generator Installation

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LionofJuda

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...and I do mean rural! Our church is planning to fund the installation of a 10KVA
generator in a remote village in Congo. I'm in the radio communications field and do a fair amount of 120/240 branch ckt work. At church this makes me the "electrical distribution expert". I still have more questions than answers about the details of this mission, but the initial trouble I see is that the generator is to be located about 1200 feet or so from the load. The wire size needed has me thinking about stepping the generator output from 240v to 480v with 480-120/240 transformers. I'm picturing a step down transformer with an integral load center that will feed up to 10 120v ckts but I may have to extend the 480v to yet another building. How do I further extend the 480v from the first distribution point to a second step down transformer? Do these transformers constitute a seperately derived source and require ground rods? These people have a 3kva generator with lamp cord strung through the trees with bare wires twisted together to provide service to a clinic. I would like to help these people but don't want to cobble something up that will get somebody killed. I would be grateful for any suggestions or resources that might be relevant. Thanks in advance.
 
does the NEC even apply in the Congo?

my first thought is that the generator and step up transformer could be packaged together, just as the step down transformer and load center could be packaged together.

jungle conditions might mean you need to get stuff that won't rot in the high humidity. that adds substantially to the cost.

the ground rods are not a huge issue but running 1200 feet of cable is. even at 480V, you would need #3. 1200 feet of #3 UF (2C with G) is probably going to cost you $5000.

I'd be inclined towards a 600V transformer to reduce the conductor size even more.

all OCPD should probably be circuit breakers as you may have difficulty getting fuses in the middle of a jungle.

a 10kva generator will likely use nearly 30 gallons per day of diesel at full load.

i am thinking this is maybe not such a good place for a do-it-yourself thing.
 
Last edited:
LionofJuda said:
...and I do mean rural! Our church is planning to fund the installation of a 10KVA
generator in a remote village in Congo. I still have more questions than answers about the details of this mission, but the initial trouble I see is that the generator is to be located about 1200 feet or so from the load. The wire size needed has me thinking about stepping the generator output from 240v to 480v with 480-120/240 transformers.
Click to expand...
Thats a good thought. You may want to consider an overhead installation using 1/0 Triplex AL. Voltage drop would be small for 10 kw.

I'm picturing a step down transformer with an integral load center that will feed up to 10 120v ckts but I may have to extend the 480v to yet another building. How do I further extend the 480v from the first distribution point to a second step down transformer? Do these transformers constitute a seperately derived source and require ground rods?
Click to expand...
Yes. It is a seperately derived system. You will need a ground rod. You would
need a disconnect with a breaker to feed the transformer. You just tap the main circuit and run to the first transformer and continue the main circuit to the second transformer.

Why does the generator have to be 1200 ft away? What size transformers were you going to use?
 
petersonra said:
does the NEC even apply in the Congo?

my first thought is that the generator and step up transformer could be packaged together, just as the step down transformer and load center could be packaged together.

jungle conditions might mean you need to get stuff that won't rot in the high humidity. that adds substantially to the cost.

the ground rods are not a huge issue but running 1200 feet of cable is. even at 480V, you would need #3. 1200 feet of #3 UF (2C with G) is probably going to cost you $5000.

I'd be inclined towards a 600V transformer to reduce the conductor size even more.

all OCPD should probably be circuit breakers as you may have difficulty getting fuses in the middle of a jungle.

a 10kva generator will likely use nearly 30 gallons per day of diesel at full load.

i am thinking this is maybe not such a good place for a do-it-yourself thing.
Click to expand...

Thanks for your thoughts. I realize that NEC could go unnoticed on a project like this but I would like to adhere to it as much as possible. As for the do-it-yourself comment, everything these people have that resembles infrastructure was done by volunteers with a heart to serve God. You may well be right that it's more than we want to tackle ourselves. That's a decision we'll have to make when I gather all the input from professionals like yourself. Thanks for your time and great comments...Darren
 
bob said:
Thats a good thought. You may want to consider an overhead installation using 1/0 Triplex AL. Voltage drop would be small for 10 kw.


Yes. It is a seperately derived system. You will need a ground rod. You would
need a disconnect with a breaker to feed the transformer. You just tap the main circuit and run to the first transformer and continue the main circuit to the second transformer.

Why does the generator have to be 1200 ft away? What size transformers were you going to use?
Click to expand...

Thanks for your reply. We are planning an overhead run for this. AL make sense. The decision on generator location may have been made without regard to technical issues. I'm trying to see what kind of latitude we have there. In any case, the load locations themselves are some distance apart from each other. I'm waiting for a drawing of the village which may give me more insight. Shooting from the hip right now I'm thinking 2 ea. 5kva transformers. This probably will never see an inductive or non-linear load. Not many vacuum cleaners or computers here! Thanks again for you time...Darren
 
LionofJuda said:
As for the do-it-yourself comment, everything these people have that resembles infrastructure was done by volunteers with a heart to serve God. You may well be right that it's more than we want to tackle ourselves. That's a decision we'll have to make when I gather all the input from professionals like yourself.
Click to expand...

I'm sure you can find a professional electrician with the proper experience and a similar desire to serve G-d.

Habitat for Humanity is a Christian organization (even if some of its volunteers are b'not yisrael). I'd suggest you contact them to see if any of their electricians might be interested in travelling to Congo with you, or if any of those electricians might know someone who is.

(And remember Lev. 19:14 -- after you leave, the people who live there are the ones who have to deal with whatever you do, no matter how good your intentions.)
 
I confess to not knowing the details of what is going on in the Congo, but I have some knowledge of third world countries from both direct and indirect experience. I have seen situations where they could turn perfectly good equipment to junk in minutes. For example, I saw 120 Volt equipment plugged into a standard 120 Volt outlet that someone had wired with 240 Volts, and someone trying to run a big 225 Amp AC welder through a pair of #12 wires stripped out of NM cable and clipped onto service wires. And that was at an ADVANCED location where they had utility power.

The problems that you will have at this installation will extend beyond wire size. Such a facility should only be installed if there is an organizational presence with the skill and and resources (MONEY) to operate and maintain it. If that presence is not there, it is going to end up as an expensive piece of iron, with the wire stolen to use for something else or to sell for scrap.

If the proposed setup will be run by an organization with solid support from the US or Europe, then it can be made to work. If it is going to be run by the residents of "Rural Congo" without that continuing support from the US, then your issues are greater than technical.

I have had long conversations about such projects with my daughter who spent 18 months at a hospital in the interior of Sierra Leone, and is now with an organization that provides medical care in West Africa. They also do community development and improvement projects.

Those projects take months to develop community involvement, for the leaders and residents to see it as their idea, and to develop a sense of ownership of what is built. She told me of cases where they built sanitation facilities that nobody would use or care for because the were not "their" facilities; they were the mission organization facilities. After a year they were being torn down for the materials.

Most of those places don't need power around the clock. With distributed demand, you might be better off to provide small generators at different locations. I suspect that for the same cost as one 10 KW generator with transformers and distribution system, you could supply several smaller generators to meet local needs. Then there would be ownership at the location of the generators and there would not be security issues with a lot of wire and equipment. There would also be a degree of redundancy from having more than one generator.

The problem with most of these systems is not getting it to NEC standards; the problem is developing the attitude and the resources for the nationals to be able to use it.
 
Political/Societal issues asside, you may be better off with some of the small Honda invertor units, one at each building. Though, I don't know the availability of gasoline over there, are you stuck with diesel?? Do they make small inverter diesel gennies? Have you thought about getting something locally so that parts and service expertise are available?

If you go with one large unit...skip the step up up transformer and get a 480 or 600V generator, then use a small Square D "Powerzone" at each building. This integrates primary breaker, step down transformer, secondary breaker, and load center in one quick to install unit.

If the loads are really light, like lighting only, what about solar systems on each building? Using LED lighting and 12v batteries may be lower maintenance, and you won't have to constantly supply fuel to the village. I've been in ski huts with a modest solar system using a few marine batteries, a charging controller, and flourescent lighting. It was more than adequate for general lighting, and you can use an invertor for medium sized loads (up to 2000W I think)
 
Bob NH said:
I confess to not knowing the details of what is going on in the Congo, but I have some knowledge of third world countries from both direct and indirect experience. I have seen situations where they could turn perfectly good equipment to junk in minutes. For example, I saw 120 Volt equipment plugged into a standard 120 Volt outlet that someone had wired with 240 Volts, and someone trying to run a big 225 Amp AC welder through a pair of #12 wires stripped out of NM cable and clipped onto service wires. And that was at an ADVANCED location where they had utility power.

The problems that you will have at this installation will extend beyond wire size. Such a facility should only be installed if there is an organizational presence with the skill and and resources (MONEY) to operate and maintain it. If that presence is not there, it is going to end up as an expensive piece of iron, with the wire stolen to use for something else or to sell for scrap.

If the proposed setup will be run by an organization with solid support from the US or Europe, then it can be made to work. If it is going to be run by the residents of "Rural Congo" without that continuing support from the US, then your issues are greater than technical.

I have had long conversations about such projects with my daughter who spent 18 months at a hospital in the interior of Sierra Leone, and is now with an organization that provides medical care in West Africa. They also do community development and improvement projects.

Those projects take months to develop community involvement, for the leaders and residents to see it as their idea, and to develop a sense of ownership of what is built. She told me of cases where they built sanitation facilities that nobody would use or care for because the were not "their" facilities; they were the mission organization facilities. After a year they were being torn down for the materials.

Most of those places don't need power around the clock. With distributed demand, you might be better off to provide small generators at different locations. I suspect that for the same cost as one 10 KW generator with transformers and distribution system, you could supply several smaller generators to meet local needs. Then there would be ownership at the location of the generators and there would not be security issues with a lot of wire and equipment. There would also be a degree of redundancy from having more than one generator.

The problem with most of these systems is not getting it to NEC standards; the problem is developing the attitude and the resources for the nationals to be able to use it.
Click to expand...


Thank you very much for your thoughts. I don't know what is driving the idea of a distributed system -vs- more locally operated generators but I think it would be a better idea. Lower fuel costs also. There is a Western presence there but these are certainly issues to consider. Again...we are still in the early, idea forming stage, but this is great information!
 
mhulbert said:
Political/Societal issues asside, you may be better off with some of the small Honda invertor units, one at each building. Though, I don't know the availability of gasoline over there, are you stuck with diesel?? Do they make small inverter diesel gennies? Have you thought about getting something locally so that parts and service expertise are available?

If you go with one large unit...skip the step up up transformer and get a 480 or 600V generator, then use a small Square D "Powerzone" at each building. This integrates primary breaker, step down transformer, secondary breaker, and load center in one quick to install unit.

If the loads are really light, like lighting only, what about solar systems on each building? Using LED lighting and 12v batteries may be lower maintenance, and you won't have to constantly supply fuel to the village. I've been in ski huts with a modest solar system using a few marine batteries, a charging controller, and flourescent lighting. It was more than adequate for general lighting, and you can use an invertor for medium sized loads (up to 2000W I think)
Click to expand...

Thanks. I have been looking at Square D's "MiniPowerZone". It seems like a good solution. Any thoughts or concerns about 600v -vs- 480v? Other than of course the reduced current and conductor size.

One of the locations I was thinking about using the PowerZone has about 8 or so houses grouped together. I think all they're expecting there is lighting so maybe a solar charged battery solution there would be fine. We would have to elevate them from the ground since I believe their roofs are thatch. Thanks again for the great input.
 
Whatever you wind up doing, consider that the power in Central Africa is typically 220 or 230v, 50Hz and plan accordingly. You won't find many 120v devices or NEMA plugs within a few thousand miles.

They'll probably be using a plug like this:

type_c.jpg
 
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