AN ARC FLASH PROTECTION 4

[11basonia]

Can someone help with the formulas to calculate the following:
1. arc current
2. incident energy and
3. flash protection boundary

the system fault level is 16KA @ 11kv

Regars,

Basonia

 

[burnt2x]

Google "arc flash calculator" refine search to filtype xls.

My $0.02

 

[majesus]

Yeah just do some googling, it is easy to find.

http://www.agsrhichome.bnl.gov/AGS/...tical Solution Guide to Arc Flash Hazards.pdf

 

[burnt2x]

Okay, got the numbers:

If equipment is a switchgear with 25 mm gap, working distance is at 18 inches, and 4 cycles (0.066 sec) total interrupting time of breaker or fuse:
Predicted arcing current = 15.41 kA
Incident energy exposure = 1.77 cal/cm2
Flash protection boundary = 28 inches
PPE level cat = 1
Please verify calcs as I made it quick.

 

[veman]

I use the calculator on

http://www.arcadvisor.com

for low voltage/switchgear calcs and the duke power utility program for MV line calcs (see attached).

 

[11basonia]

In an ARCING CURRENT CALCULATIONS THERE IS A FORMULA USED TO MANUALLY CALCULATE ARCING CURRENT WHEN GIVEN BOLTED CURRENT,CABLE GAP, ETC.THE FORMULA IS :

IgIa= 0.00402+0.983*IgIbf

1.What is Ig in this formula and what is the simplified formula to calculate Ia ( arcing current)?
I have been trying to calculate arcing current using this formula above and comparing the answer with the one in

http://www.arcadvisor.com

calculator but, could not find the same answers.I think, perhaps am missing something in the formula, Can some clearify the formula?
Regards, BASONIA

 

[wbd]

It is not Ig but lg as in Log base 10.

 

[Senselessticker]

Just be careful using internet software. I'm not saying it doesn't work (I'm sure 99% work just fine), but most "successful" companies will have quality procedures in place that verifies software reliability. I don't like it, but I have to prove (by hand calculation sanity check), that any softare I use produces reliable results. If you or your compnay can be held responsible for the accuracy of the results. Be sure you have cya.

 

[Zogzog]

Yep, we are starting to see companies specicify what software is used for an arc flash study. Usually they require SKM or ETAP. No internet software is allowed to perform the studies. Again I agree with Senslesssticker (Love that name BTW) they probally work OK but CYA.