I have been asked to do an overview of the changes for manufacturing, engineering and service
at our facility.

I know this is a loaded question, but

What is a reasonable amount of time needed to cover the essential changes to NFPA 70E?

Wow, yes what a question! Items that come to mind are:

1. Qualified versus unqualified worker training
2. What is in your written Electrical Safety Program that is affected by the changes?
3. What voltage levels do you have? (thinking about utility like that would be affected by new 1910.269 rules)
4. Items such as the risk table where operating a circuit breaker with the specified conditions does not require AR PPE
5. Was an analysis done at your site or are you using tables from NFPA 70E
6. DC arc flash applicable?
7. Risk assessments?

Thanks Barry

1. Covered this already
2. I will have to get our ESP out and see.
I did cover Electrical Safety Plans already, but did not tie it to our specific plan yet
3. We have up to 690 VAC, up to 1000 VDC, and I have to check the primaries on our utilities
4. I am looking at the risk tables
5. An analysis was done and I have a copy of it
6. DC Arc Flash is definitely applicable.
We have DC bus voltages that normally are around 700V but can get up to 1000V on our Energy Grid Tie inverters
7. Yes, I have the last risk assessments and plan to cover it in the PPT as well.

I am about 24% done with the PPT, so I have plenty of time to add and rearrange things.
I seem to remember a chart that gives minimum Arc Flash Boundaries based on the HRC,
but for some reason I can't seem to find it again. Am I experiencing brain flatulence?

Depends on how in depth and how different your current policies are relative to 70E-2015. Estimate if you do decent slides using recommendations out there, about 1 minute per slide.