malachi constant
Senior Member
- Location
- Minneapolis
Hi all,
I'm an engineer about to submit a quote for my first (kind of) arc flash study. (Ten years ago when I was a few years out of school I entered the SKM data in a study for another engineer, so it's not a completely foreign endeavor for me.) I know SKM fairly well having used it for ten years to do fault calcs. I've been reading some good articles on EC&M and browsing the comments here, I think I have a pretty good idea of what needs to be done - a "humble but confident" attitude. I'm also about to purchase the IEEE-sponsored book on ARC Flash Hazard Analysis and Mitigation to help fill in any knowledge gaps once I get going.
The study is commissioned by a local school district that wants arc flash calculations done for service switchgear only on each school in the district - a little over a dozen buildings. We (or the district) will hire a contractor to do the field investigation. I'm trying to figure out our engineering fees for this (not the contractor fees). I figure I will need to:
1. Collect or set up drawings to identify each building's service and transformer locations.
2. Visit each site, however briefly, to see each service with my own eyes and look for any red flags. (Contractor will be collecting most of the data on their own without me looking over their shoulder.)
3. Coordinate with utilities to get fault and impedance data. (I believe there are two utilities that serve this district.)
4. For each building: set up the SKM files, create simplified one-lines, run short circuit studies, run multiple-scenario arc flash studies, read through data, etc etc etc
5. Write report, make recommendations, print labels, etc.
6. A couple misc meetings.
So...for an mile-high overview of what needs to be done on my end, does this look about right? More important question, does anyone have a good feel for engineering time per facility for something like this (keeping in mind study is for "service gear only"). My first pass put me at 8 hours per facility to do all that, which seems low -- I'm thinking it might be double that (or more). For comparison, if I was doing the short circuit study, which I have down to a science, I could crank it out in about 2-3 hours per facility easy (service only, going off drawings and utility data - might take a day if I was doing a whole good-sized school, not just the service). I don't mind if we lose a little money getting up to speed on arc flash but want to have fees that are reflective of the typical amount of work involved.
A follow-up question would be what do you think the contractor's fees would be relative to the engineer's? We don't have those yet, and probably won't until our fees are set, but wondering if 50/50 is about right, or is one party spending a lot more time than the other?
I should add I worked as an electrician's apprentice in the past, have attended arc flash safety classes, read Donnie's Story, and have an uncle that got on the wrong side of a fault twenty years ago (and survived after a long hospital stay). I appreciate the danger, and even more so appreciate the human beings who are faced with the danger on a daily basis. I hope I take this stuff sufficiently seriously so as to not cost anyone their lives or health.
Any comments are appreciated!! Thanks and have a good weekend!!
I'm an engineer about to submit a quote for my first (kind of) arc flash study. (Ten years ago when I was a few years out of school I entered the SKM data in a study for another engineer, so it's not a completely foreign endeavor for me.) I know SKM fairly well having used it for ten years to do fault calcs. I've been reading some good articles on EC&M and browsing the comments here, I think I have a pretty good idea of what needs to be done - a "humble but confident" attitude. I'm also about to purchase the IEEE-sponsored book on ARC Flash Hazard Analysis and Mitigation to help fill in any knowledge gaps once I get going.
The study is commissioned by a local school district that wants arc flash calculations done for service switchgear only on each school in the district - a little over a dozen buildings. We (or the district) will hire a contractor to do the field investigation. I'm trying to figure out our engineering fees for this (not the contractor fees). I figure I will need to:
1. Collect or set up drawings to identify each building's service and transformer locations.
2. Visit each site, however briefly, to see each service with my own eyes and look for any red flags. (Contractor will be collecting most of the data on their own without me looking over their shoulder.)
3. Coordinate with utilities to get fault and impedance data. (I believe there are two utilities that serve this district.)
4. For each building: set up the SKM files, create simplified one-lines, run short circuit studies, run multiple-scenario arc flash studies, read through data, etc etc etc
5. Write report, make recommendations, print labels, etc.
6. A couple misc meetings.
So...for an mile-high overview of what needs to be done on my end, does this look about right? More important question, does anyone have a good feel for engineering time per facility for something like this (keeping in mind study is for "service gear only"). My first pass put me at 8 hours per facility to do all that, which seems low -- I'm thinking it might be double that (or more). For comparison, if I was doing the short circuit study, which I have down to a science, I could crank it out in about 2-3 hours per facility easy (service only, going off drawings and utility data - might take a day if I was doing a whole good-sized school, not just the service). I don't mind if we lose a little money getting up to speed on arc flash but want to have fees that are reflective of the typical amount of work involved.
A follow-up question would be what do you think the contractor's fees would be relative to the engineer's? We don't have those yet, and probably won't until our fees are set, but wondering if 50/50 is about right, or is one party spending a lot more time than the other?
I should add I worked as an electrician's apprentice in the past, have attended arc flash safety classes, read Donnie's Story, and have an uncle that got on the wrong side of a fault twenty years ago (and survived after a long hospital stay). I appreciate the danger, and even more so appreciate the human beings who are faced with the danger on a daily basis. I hope I take this stuff sufficiently seriously so as to not cost anyone their lives or health.
Any comments are appreciated!! Thanks and have a good weekend!!
hmy:
