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| Obtaining Electric Utility Data for Arc Flash Studies? https://brainfiller.com/arcflashforum/viewtopic.php?f=33&t=3521 |
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| Author: | Jim Phillips (brainfiller) [ Sun Oct 26, 2014 8:23 pm ] |
| Post subject: | Obtaining Electric Utility Data for Arc Flash Studies? |
How Easy is it to obtain electric utility data for arc flash studies? Easy Needed a little nudge Difficult Impossible Depends on the utility |
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| Author: | wbd [ Mon Oct 27, 2014 5:11 am ] |
| Post subject: | Re: Obtaining Electric Utility Data for Arc Flash Studies? |
I voted for It Depends for several reasons. One is that in areas where I have done work before I already have established contacts and a relationship with the engineering staff, so it is easier. I have found that the larger the utility the more difficult it can be as not all utilities have an Account Representative assigned to industrial accounts. With larger utilities it takes a while to get to the engineering staff and the first response is from Customer Service where the maximum possible short circuit current based on transformer size is provided. I will say that utilities have gotten much better at providing the information than when I started doing these studies over 10 years ago. One of my worst experiences was large west coast utility where it took about 7 to 8 months and that was only after a strong email referencing the state's Public Utility Commission. |
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| Author: | jghrist [ Mon Oct 27, 2014 6:41 am ] |
| Post subject: | Re: Obtaining Electric Utility Data for Arc Flash Studies? |
I voted "Difficult", but it really depends on what information you want. It is usually not difficult to get maximum fault data at the service. Most utilities will also provide fault and/or Thevenin equivalent impedance data at the primary of the transformer and the transformer impedance, at least for medium voltage service. Getting minimum fault current data and high side protection data is usually difficult. |
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| Author: | 37Reasons! [ Mon Oct 27, 2014 7:02 am ] |
| Post subject: | Re: Obtaining Electric Utility Data for Arc Flash Studies? |
In addition to the difficulty with large utilities there is also a significant problem getting factual information from smaller co-operative types of organizations. I have actually had the experience of the contact not knowing the primary fusing, transformer impedance, or distribution voltage. The answer I was given was "Try and stop one of our truck in the are and ask them!" So I voted for It depends |
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| Author: | JKlessig [ Mon Oct 27, 2014 9:14 am ] |
| Post subject: | Re: Obtaining Electric Utility Data for Arc Flash Studies? |
Very VERY much depends on the utility. I most often deal with two, PG&E, and Silicon Valley Power. WIth PG&E its like rolling dice, sometimes you get great detailed information, some times you get very questionable data, some times you get no response. More recently they have gotten more uniform, and have a form letter they append to all data provided that says in effect "the max and min faults in our system are such and such" implying that you should be using those numbers. This ignores the issue that the "min" is at the rear end of some long rural feeder, and the max is a set of networked transformers in a dense urban environment. For a while they were trying to charge $500 and up for information. I always dealt with that by asking for the tariff that allowed for that charge. And in my opinion, NO ONE at PG&E ever actually answers the phone. They might call you right back after you leave a VM, but they wont answer. With SVP I have never had a problem, responses have always been timely, and full of information. |
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| Author: | Voltrael [ Fri Oct 31, 2014 5:55 am ] |
| Post subject: | Re: Obtaining Electric Utility Data for Arc Flash Studies? |
I voted easy, because for me it was. I think it was mainly just because they are easy utilities to work for. Two things that probably help though are that a) we are one of the largest customers, and b) I used to be an employee of both the distribution utility and the transmission utility at different times in the past. |
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| Author: | CarlM [ Mon Nov 03, 2014 7:13 am ] |
| Post subject: | Re: Obtaining Electric Utility Data for Arc Flash Studies? |
Depends. I've had no reply or just plain bad information from some offices of NYSEG and others were more helpful but not a lot of information usually. Here in NW Vermont he have/had a number of electrical utilities and the ones Voltrael deals with had been really pretty good. |
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| Author: | Namgay Tshering [ Fri Nov 07, 2014 10:50 am ] |
| Post subject: | Re: Obtaining Electric Utility Data for Arc Flash Studies? |
I voted "Needed a little nudge" because it wasn't easy or difficult, altleast in my case. I still remember back in 2012, when I called PG&E and asked for utility information, they were like, we can't give all this information to you. I calmed them and submitted all paper works from customer side as they asked me to do, so that my RFI is genuine. Once I established a bond, I always shoot my RFI to that office regardless of the plant site and request them to forward to their responsible engineer to obtain data. And I do the same with all the utilities that I deal with. Sometimes, when I don't hear from them, it requires little nudge but in most of the cases, it works like charm as m no longer stranger to them. |
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