I represent an investor owned utility and am involved with developing our NESC arc flash compliance policy.

We have over 300,000 customers in a service territory of approximately 300 square miles.

We use Aspen to model our transmission and distribution network and to derive our short circuit and relay coordination settings.

I would be interested to hear what software packages and/or methodology are being used by other utilities to calculate the arc flash energy levels on their systems.

Arc Flash Software

I am a utility consultant and will be performing about 20 studies for our clients in the southeast. I am planning to use Arcpro for the high voltage portions of the systems. Have not completely decided on the below 1000 volt portions yet. This would include transformer banks, padmounts, transclosures, switchgear, etc. I am thinking that it will depend on the likelyhood of a line to ground fault progressing to a 3 phase fault. I have also toyed with the flux program from Duke Energy to see how it will compare with Arcpro for the primary portion of some systems (if I am ever able to get my software key for Arcpro). They say it takes 2 weeks? What's up with that?

Still also debating whether to use a cut off time for low level faults that will be below the level of the instantaneous pickups, as well as, an extra switch to set up alternate settings for maintenance when the breakers are placed on single shot. Needless to say, not very practical for those with electro-mechanical relays.

Any thoughts? Alan

Arcpro for Utility Studies



MedleyK:

I have checked some sample calcs up to 36 kV with Arcpro against table 410-1 in the NESC and the values are dead on.

The interesting part is the they appear to "bracket" the voltage such that for a given value of fault current, the energy level is constant for 5, 10, or 15 kV.

They also only model stainless steel and copper, no aluminum with stainless being the worst case, and it is the calc that matches the NESC table.

The software cost is approx. $1700.00 but be advised, it takes 2 to 3 weeks to get a password to activate the product....Go Figure....it was emailed to me!

Arcpro for Utility Studies

Alan,

what are your conclusions after trying the flux program from Duke Energy? Did it compare with Arc Pro or NESC tables.

The advantage of using the flux program is that their equations are published.

Thanks

Arcpro for Utility Studies

John,

Sorry, but it has been so long since I did those calcs with the flux program that I cannot remember the results.....maybe someone else here does?

Alan