Figuring Arc Flash for a Machine

Been looking all over the net for ways to fuigure the Arc Flash Rating of a machine. Found some free calculators, but everything is for High Vlotage. I Have just a simple machine that I want to make sure has the correct labeling on it. Nothing more than 480VAC, 3 Phase, into a 15A (AB 140U Series Breaker) Disconnect Enclosure, running 4 motors, a 1.5kVA Transformer and a 10A DC Power Supply.
I am just not able to find what the particulars are for figuring the rating.
Any kick in the right direction would be appreciated

Thanks for taking the time help.

A machine does not get an 'arc flash rating'. It gets a label advising a worker of the amount of available incident energy or the PPE required.

You need to calculate the amount of arc flash incident energy available at the machine. This involves knowing the amount of bolted fault current at that location and the amount of time it will take a protective device to clear that fault current. After that you can use the formulas in the appendices to NFPA 70E.

You may be able to find some DIY tools at www.arcflashforum.com.

Thanks. I thought every device down to, and including, the machine had to have it's own "Arc Flash Rating".
Now for that "Bolted Fault Current" Where on the breaker characteristics chart do you find that? There is the trip curve, but who decides at what point to you use the amperage figure?
I seen in one of the descriptions, a trip "typical" trip time of 9ms and it looks as if 455mm is the working distance for 480VAC, but how do you double check that you are using the right figures?

Jim Dungar said:

You need to calculate the amount of arc flash incident energy available at the machine. This involves knowing the amount of bolted fault current at that location and the amount of time it will take a protective device to clear that fault current.

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Wouldn't you first need to know how much juice you are feeding the panel - the power supply to the panel. Then look at the panel's ability to clear the fault.

The amount of available short circuit amps (SCA) during a 3-phase bolted fault is the key. The SCA at the service entrance is not the same as the SCA at the piece of equipment. Circuit conductor impedances and motor contribution must all be taken into account.This means that some type of 'short circuit' calculations need to be performed.

The protective device must be rated to clear the available SCA at its line side terminals. The equipment must be rated to withstand the SCA at its lugs until the upstream device clears, this is its SCCR. The 'listed' AIC rating of the protective device (fuse or breaker) is not part of an arc flash calculation.

The amount of arc flash incident energy has to due with timing.
Once you have determined how much bolted SCA is actually available at the equipment, you convert it into an arcing fault value. You then use the protective device TCC to determine how long it will take to clear the calculated arcing fault current.