LED inrush current and generator set

mapj1:

It is perfectly reasonable to start a genset and get it connected to full load in a little under 5 seconds, but it is not often achieved. Firstly that will be a machine with an oversize turbo charged diesel and not such a heavy flywheel, so it will not be so good on step loads, and if you want it to start and rev hard, it will start with a great cloud of black soot, compared to a slow spin-up design.


Normally for events we'd program in some hang over to the genset, so that if it decides to come on it then keeps running  for at least a few minutes, even if it is not needed because the power comes back on almost straight away.


For seamless power transfer there are battery inverter based UPS systems, that basically join the inverter waveform on to the incoming mains to the nearest whole cycle,  but these are large, expensive and probably overkill and harder to maintain than a selection of maintained emergency lights. With an inverter UPS expected to  hold up for say 30- 60 seconds (from a design with batteries sized for a run time of maybe 5  to 10 minutes at full load ) you can afford to have a 10 second start time, or longer, allowing for a few crank and coughs from the gensset and set a long pre-trigger delay to avoid the false start problem on every flicker of the mains.  I think the times you are looking at are from that sort of design.

 

It seems that a system with a UPS is the perfect solution, but it is very expensive.

I will try to solve the problem without a UPS, only with a genset.

 

mapj1:

It is perfectly reasonable to start a genset and get it connected to full load in a little under 5 seconds, but it is not often achieved. Firstly that will be a machine with an oversize turbo charged diesel and not such a heavy flywheel, so it will not be so good on step loads, and if you want it to start and rev hard, it will start with a great cloud of black soot, compared to a slow spin-up design.


Normally for events we'd program in some hang over to the genset, so that if it decides to come on it then keeps running  for at least a few minutes, even if it is not needed because the power comes back on almost straight away.


For seamless power transfer there are battery inverter based UPS systems, that basically join the inverter waveform on to the incoming mains to the nearest whole cycle,  but these are large, expensive and probably overkill and harder to maintain than a selection of maintained emergency lights. With an inverter UPS expected to  hold up for say 30- 60 seconds (from a design with batteries sized for a run time of maybe 5  to 10 minutes at full load ) you can afford to have a 10 second start time, or longer, allowing for a few crank and coughs from the gensset and set a long pre-trigger delay to avoid the false start problem on every flicker of the mains.  I think the times you are looking at are from that sort of design.

 

It seems that a system with a UPS is the perfect solution, but it is very expensive.

I will try to solve the problem without a UPS, only with a genset.