There is a large difference between the National Electrical Code (NEC) & the EU & UK. Requirements.
Firstly, as BS7671 has been mentioned above, be aware that this does not cover a LOT of manufacturing equipment, Lucy, you don't state your industry, but, humour me, and let me say for now it is Automotive.
BS7671 does not apply to the machine tools seen in the automotive industry.
You also need to understand the potential energy at the point of test.
At the origin of the installation under BS7671, you could see very high potential fault currents, however, these will almost certainly be limited by network design by the Distribution Network Operator (DNO) to be <35kA line to ground in your area.
The further you move away from the origin, the lower this potential fault current becomes.
Now at a typical Automotive machine tool, you could have 24, 48V d.c., 24, 48, 110, 230 & 400V a.c.
Now anything on the control circuits of the machine, unless it is very old will have further energy limitation by virtue of how the reduced voltage is derived.
d.c. Supplies can only deliver the potential fault current that can be generated by their respective power supply generation devices. Typically switched mode power supplies (SMPSU).
I would be amazed if there is sufficient energy to create an arc flash at these supply levels.
I've tried and failed to get this to happen.
Don't ask!
Now going up to 110/230 V a.c. Control, if the machine is constructed to CE requirements, then there will again be a "device" between the control system & the mains supply, this again will provide current limiting.
BS EN 60204-1 requires that any control supplies are fed from a transformer (Tx) / power supply (PS).
Compliance with this standard (Std.) is "required" for CE marking.
Now, this Std. Also requires that the PS or Tx has over current circuit protective devices (OCPD) on the input & output of the device.
Now these OCPD's also have current limiting properties, as do ALL circuit protective devices.
This is known as the energy let through, and is described in Amp squared seconds.
These are just SOME of the things that go to reduce the energy available at a typical manufacturing machine tool to a level where it is IMHO impossible to instigate an arc flash on the control circuits.
Please note we are at this stage only talking about control circuits at this stage.
There is more, but, it is Saturday evening, and I'm about to pop off for some dinner! ;)