I need you help.
I am designing a system where I want to use a cable tray outdoor. I would like to drop my cable ( 2500A ) on top of an outdoor bussed section.
Do you know any vendor of watertight seal I can use to drop my cables to an outdoor switchboard? I have been asking assistance from...
Or the city may have thought that its redundant to keep that section of the Code why they have decided to delete it as so long that you install the partition per its listing intruction. Call the city and find out why.
RBULSARA,
I am leaning towards your interpreatation because the NEC handbook' refers an example to a small hospital with a max capacity of 150 KVA. But how the NEC defines essential system does not convince me that it is referring to the 'total' essential load. I may be wrong but I could not...
Thanks for the reply, BJC but I don't get what you mean. 517.30 (B)(4)allows combining the life safety with critical and equipment auto provided that the maximum demand in the essential system ( which is composed of life, critical, and equipment auto) is 150KVA. My question is this:
Can I...
I am new to the forum but I have learned quite a lot by just reading through different threads. I need your input on the intent of 517.30(B)(4) on this scenario.
If I have an essential load consisting of 50KVA Life Safety branch, 100KVA critical circuit branch, and 150KVA non delay equipment...
JBartos,
I obtained above equation from SKM Power Tools (DAPPER Comprehensive Short Circuit Reference and A_Fault Reference). It is a general equation which lets you compute for the RMS and PEAK current at any cycle or time frame.
For the 1st 1/2 cycle fault (where highest peak occurs), c =...
Can anyone pls tell me how the following formula for assymetric current (rms) and (peak)from a power system manual has been obtained.
I asym (RMS) = I"k * sqroot (1+2e^[-4(3.14)(R/X)C]
I asym (peak) = I"k * sqroot(2) * (1+e^[-2(3.14)(R/X)C]
where C = cycle
I"k - initial symmetrical fault...
