Haiti: construction of temporary shelters in series

[Herve42]

Newcomer on the forum, Hello everybody.

I have been working in Haiti for 10 days on behalf of a humanitarian organization.

I am in charge of setting up a production unit to mass produce temporary shelters, also called "shelters".

I have a problem to calculate the quantity of electricity which will have to be supplied to feed my "factory".

Here are the machines I will use:
10 band saws, 20 radial saws, 10 panel saws, 10 drill presses, 10 compressors (to clean machines with compressed air)
.
The material will not be industrial but presumably Dewalt.
I count 2 kw of power per machine, which makes me: 120 KW, using a converter found on the web, it gives me 150 KVA.
If I have to buy a generator of this power, it's 30 000USD, and I do not have them in my budget.
But I especially feel that my calculation is wrong, indeed a generator of this size is huge in power and seems disproportionate to my needs.

Could someone advise me. Thank you in advance, and hoping for a quick response, because I have to start the production, you can imagine.
Regards
Hervé

[Christophe]

Hi and welcome.

150 kVa is huge without being ...

Your calculation is just a flat: the machines will not necessarily turn all 100% at the same time and the unit power of 2kW is to refine.

For example, 2 kW for a drill press is a lot but it is (very) little for a sawmill band saw ... it all depends on the size of each tool of course ...

In addition, putting 100% of rotating machines on a generator can cause problems of current draw at startup / torque variation.

Make us a more accurate list of the materials you want to use please.

[elephant]

All this is intermittent. and 2 KW seem to me a lot for a drill press, for example.
A good average would seem to be 1,5 KW per worker.
Let's not forget that, for example, a saw has a consumption proportional to its load.

Compressors will do just that, but maybe a tenth of the time in this kind of use.

I remind you that there are relays of load shedding: we can give priority to the saws compared to the compressors (to choose them with big reservoirs)

[Alain G]

Welcome to Econology Hervé42



10 band saws> 500W = 5W, 000 radial saws> 20W = 1W, 500 panel saws> 30W = 000 drill presses> 10W = 1W, 500 compressors (small portable model)> 30 at 000,10W = 500 to 5W

5 000 + 30 000 + 5 000 + 8 000 = 48 000 watts

48 000 watts used at 50% of the time 24 000 watts + safety margin of 10 000 watts 34 000 watts is more than enough if you do not start all the devices at the same time!

So 35 kilowatts would be enough or if you want to be sure, go with 50 Kw!

Naturally the compressor must be started first to be full before using the other devices and you must warn the volunteers not to push the devices too, so you will have enough power because the devices will consume only a fraction of their consumption !



Good luck!

[elephant]

I do not know if we need everything: we do not do everything at the same time. But it is difficult to realize the atmosphere of his site. I remain convinced that it is difficult to consume more than 2 KW per worker.

[Herve42]

Hello everyone and thank you for your quick response.

I will take into account your valuable advice, starting on a basis of 50 KW, and add to the ladle for the rest of the power consumption: lighting, office (computer, printer etc ...).
I have the information that the owner of the local proposes to provide us with electricity, so I no longer have to buy a generator. I will ask him what maximum capacity he can provide, and advise according to that.
Since I am not very precise in my request, I will rely on an overconsumption to be sure. In any case I will only pay what I consume. What matters to me is having enough power to run the shop.
Thanks again for your help, I now have a basic reference.
Regards
Hervé

[Former Oceano]

Good if you get electricity.
By cons between a large group, is not it better 2 groups of half the power of the wholesale?
This is to have less bulky equipment to carry and store.
To be able to do maintenance without being in shortage of energy (emptying, change of parts if failure, ...).
It is even possible 2 groups come back cheaper because more sold than a big group less sold so not depreciated for the industrialist ...

[bernardd]

I had thought of the same thing, with more advantages:

- if one is down, the other one remains ... (damn already said ... but so true!)

- a diesel group used at less than half of its rated power seems not to like at all, according to a specialist consulted.
He dies very fast. The group, not the specialist :-)

[Herve42]

Hello,
for the generators it's not stupid, I'll think about it in case I need this remedy.
Thank you for the info
Hervé