10 second generator start

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I don't know the actual reason, but I figure it is a balance of what is mechanically feasible, and the amount of time people start to freak out in the dark.:lol:
 
We had a similar question, related to emergency lighting power sources, and we found the answer in NFPA 101. Back in 1997 it was in section 5.9.1.2, I'm not sure where it's found in the current version.
 
7.9.1.3 in NFPA 101 - 2009 is where it was at, don't have the 2012 book. But the last couple jobs I have done were designed under 1997 life safety code, good ole Michigan, leading the way ;)
 
Prox said:
7.9.1.3 in NFPA 101 - 2009 is where it was at, don't have the 2012 book. But the last couple jobs I have done were designed under 1997 life safety code, good ole Michigan, leading the way ;)
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We have had that requirement here in Georgia at least 20-30 years, this is not a new rule.
 
Its to allow time for temporary flickers, outages or spikes. The transfer switch prevents a lot of un nessecary starts and stops of the gen set. Everytime that gen set comes on there is at least 10 minutes of cooldown.
 
I appreciate the responses, but back to the original question, why 10 seconds? I know where it is in Chapter 7 of NFPA 70 (NEC), just trying to find out why 10? Why not 15 or 20?

It has been 10 seconds for a long time, so I don't think it is a technology issue.

Someone had told me that it is a throwback to original design of nuclear plants where they felt that the water cooling of rods needed to resume in 10 seconds or meltdown.
 
10 second generator start

It would make since to me to have the delay instead of a instant start if for nothing else then to see if the recloser could spare an outage altogether.
 
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