Need Help To Size A Generator

Approximately 22kw/28kva.

Total up the power kW that you need, add reserve margin , say 30%, divided by power factor 0.7 to 0.8, this will give you the kVA of your genset.

Hi,

There are few factors which you need to consider for selecting right Gensets ..

Since, your loads are 1 phase, a 1 phase genset would be ok. but i would suggest to have 3 phase if you can distribute your load equally. However it seems to be difficult so please go for 1 phase Genset ...

Now, the second imp thing is non-linear loads ..... I dont see a much problem with this for you .... you have PC + Emergency lighting load which may come under this category but its only 2 Kw which is almost 8% only. so, it's also ok.

The third imp things is loading, how you want to load your Ganset ... this means you cannot put all your 100% load on Genset ones ..... but I guess .... you can manage this .... Normally your Genset vendor will give you this detail.... We called it step loading of Genset ....

The fourth one is altitude of site, if it's above 1000 asl, please consider a factor 0.9 for Genset rating calculation

Actually, all above mention points are rarely consider in small Genset selection .... so, if you do not want to go in details ..... just calculate your kW load, take a power factor of 0.8 and with 20% margin calculate the required kVA rating and select the next avialable standard rating Genset ....

J.... Cheers

You should take into account the diversity factor(loads running simultaneously) also to size the generator.It is better draw a chart with time in X-axis and load in Y-axis over a period of time(8 or 24 hrs) and get the total (max load)in vertical column.

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