I am geting a masive project on my lap! - Page 1
Forum section: electronics / projects

author: Tranan
author_rank: Contributor
timestamp: October 01, 2013, 08:58:05 pm
content: In 2 weeks I am starting my graduation work as a power engineer.The task at hand is mapping the electric system in a government building. Thats from the 22kv/400v transformer to the outlet.Have any of you guys been involved in a similar project?I am a bit worried cos what they said "The system is under dimension and mostly undocumented and we want you to go thur it and document and suggest changes."Help! I only got one project under my belt. And that was only a economic calculation on solar panels./Thomas

author: Bloch
author_rank: Unknown
timestamp: October 01, 2013, 09:20:24 pm
content: >I am a bit worried cos what they said "The system is under dimension and mostly undocumented and we want you to go thur it and document and suggest changes."How is is under dimension ? ie is the cables to small for the fuses / they did expect that all outlet's can be loaded 100%

author: Fsck
author_rank: Super Contributor
timestamp: October 01, 2013, 09:24:25 pm
content: Does "under dimension" mean "underspecced"? as in insufficient capacity for the usage requirement?

author: madires
author_rank: Super Contributor
timestamp: October 01, 2013, 09:26:34 pm
content: An electricians nightmare :-) Are you asking about the best tools to use or about project self-management?

author: Tranan
author_rank: Contributor
timestamp: October 01, 2013, 09:31:23 pm
content: The only thing I know so far is that they don´t know a lot of the wiring and they want it documented. The building is like a hangar with a overhead crane and a guard both. And the contractor used a subcontractor that did not follow the standard on documentation and and it pollutes the grid when the crane is operating and if it has any load It blows the beakers.And I have no idea how to crack this one. Well I guess I get a better idea wen i get access.

author: Tranan
author_rank: Contributor
timestamp: October 01, 2013, 09:39:09 pm
content: "under dimension" mean "underspecced" yes!And I want help with tools and project self-management.thanks.

author: madires
author_rank: Super Contributor
timestamp: October 01, 2013, 09:45:28 pm
content: Well, the first thing would be to define the exact goals:- documentation of the complete wiring- analysis of utilisation (hint: any undersizing)?- fix for the crane problem?For the documentation you'll need a blueprint of the building and map the wiring. CAD software for architects should do the job.

author: Tranan
author_rank: Contributor
timestamp: October 01, 2013, 09:52:32 pm
content: Thanks! I am getting a bit panicking!

author: Frenchie
author_rank: Regular Contributor
timestamp: October 02, 2013, 01:12:30 am
content: General engineering advice I wish I was given when I was a grad:Don't panic, It gets easier.

author: nctnico
author_rank: Super Contributor
timestamp: October 02, 2013, 01:35:01 am
content: Indeed. Worrying is like chewing bubble gum to solve an algebra equation.@Tranan: what did you learn in school about taking on a project? Do you have any books or other reading material on that? Most people fresh out of school tend to forget what they learned and take on projects in a totally unorganised way. Don't make that errorThese sort of projects are like reverse engineering and they usually consist of the following steps:- locate and identify all components in a system and put them on a map (if there are many components group them together by room or a location)- find out what the function/specification is of each component- find out how the components are connected (maybe create a top-level and split that into rooms/locations)The key is to work systematically and stay calm. Take breaks to clear your mind.I'm sure that in the end you will get a diagram which is surprisingly simple and the source of the problems will be easy to spot.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: October 02, 2013, 01:39:25 am
content: Any time, cost, manpower constraints?These can help you panic if the size/scope of the project isn't enough.

author: Psi
author_rank: Super Contributor
timestamp: October 02, 2013, 03:27:14 am
content: It sounds like you're going to need to disconnect cables just to see what loses power and where the cable goes.I'm not a power engineer, so don't take what i say as 100% correct. However here's how i would approach the problem...First go around and make a map on paper (in only one pen color) of how you think the building is wired based on what you can see.Then you can write a testing plan to confirm your assumptions by disconnecting and testing things.All your findings from testing get written in a different pen color! this way you wont get confused by what you "think" vs what you've "proved/tested"Making up a test plan also gives you a list of things to check without needing to think about it too much onsite where there's lots of distractions.It also makes it easier to run through testing things quickly which maybe important if you have limited time where you can cut power to things.

author: Bloch
author_rank: Unknown
timestamp: October 02, 2013, 04:13:51 am
content: Quote from: Tranan on October 01, 2013, 09:31:23 pmThe first thing check that the crane has it own breaker. 2. Check size on breaker vs current written on type plate on crane.

author: pickle9000
author_rank: Super Contributor
timestamp: October 02, 2013, 05:24:22 am
content: Don't ignore the people operating the systems, take notes, have them explain how things work (or are supposed to work). Tell them they are the expert operators and you need their help. Find out where the real problem areas are and give them appropriate priority. Do this yourself if possible, it will aid you in determining the overall scope of the mission.Good luck

author: vk6zgo
author_rank: Super Contributor
timestamp: October 02, 2013, 05:46:22 am
content: You will go home,covered with dust,with a blinding headache,& more tired than you have ever been in your life.You will get it done,however,& when memories of the agony subside,the satisfaction of a job well done will remain,as well as the knowledge you gained by contronting problems & overcoming them.

author: Tranan
author_rank: Contributor
timestamp: October 02, 2013, 06:43:52 am
content: Quote from: HackedFridgeMagnet on October 02, 2013, 01:39:25 amManpower = MeCost restraints = if they had a budget they might had a consultant but I guess its what I can borrow on site.Size = A large building. with a overhead crane and a Gard both. So I guess A lot of light fixtures and electrical outlet every 5m or so and a 3phase every 15m. and don´t forget ventilation/heating. Building 45X30X12mTime = 5 weeks.

author: Tranan
author_rank: Contributor
timestamp: October 02, 2013, 06:59:17 am
content: Quote from: nctnico on October 02, 2013, 01:35:01 amThanks. our project management was nonexistent.So during breakfast I dream up this.1. take notes from staff2. draw a plan over the building with all outlets an boxes and what not3. See what is connected to what and how4. calculate if it up to scratch5. measure the crane influence on the net6. calculate concretion fore crane7. collect the data and compare to the standard8. Do the report9. make out the list of needed corrections10. Do the presentation to the boss and collect grad papers.

author: madires
author_rank: Super Contributor
timestamp: October 02, 2013, 01:53:44 pm
content: Quote from: Tranan on October 02, 2013, 06:59:17 amA project management lecture should be obligatory.QuoteJust to get an idea about the problems.QuoteAlso include the wire types (cable type, number of wires in a cable, cross section), socket types, breakers, switches, contacters and so on. Use the standardized drawing symbols. Electricians and architects got planning/CAD software for that. If you're lucky sockets and breakers are labeled. If not, ask if you should also label them (bonus points :-). Make sure that you get the wire lengths approximately (you should know why :-) and note loads (lights, large machines, estimate sums for small stuff) for the analysis.QuoteThat might be the hardest part (also by time).

author: G7PSK
author_rank: Super Contributor
timestamp: October 02, 2013, 02:12:04 pm
content: The crane problem is most likely due to muck on the power pick up rails, I have seen that build up to the point that the crane ceases to work but until it does you get a lot of arcing.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: October 02, 2013, 02:19:43 pm
content: QuoteIts actually strange that you asked if anybody had done a similar project. I just remembered that I have done one. But not as in depth as yours.It did maximum demand calcs for a buildingveryapproximately 40 x 25 x 8. IIRC it was about 300A maximum demand. We had a main switchboard, and 3 large sub boards, and the Air conditioning had its own sub board too.I didn't have to plot all the paths of the wiring but I had to check every subcircuit for correct cable sizing , breaker sizing and fault current breaker sizing.Then made up a large spread sheet to calc maximum demand for the mains and sub mains. These calcs had to follow Australian wiring rules which are based on some sort of statistical analysis that was the hardest bit.If i can add anything to the previous advice, yes get very organised, including getting a bit of a time line/gant chart going just for practice. I just use excel but i am sure others do things differently.Write down all your tasks, initial time estimate, current time estimate to complete, time taken, etc.Any task that you are really unsure of, have a crack at them early, as you cant have a good estimate until you understand the particular task.Do spend a bit of time thinking about the tools you will need to complete your job.

author: Tranan
author_rank: Contributor
timestamp: October 02, 2013, 05:01:14 pm
content: Quote from: G7PSK on October 02, 2013, 02:12:04 pmThis is a spanking new building! max 6 months. so hopeful it is some what clean!

author: olsenn
author_rank: Frequent Contributor
timestamp: October 02, 2013, 05:20:28 pm
content: QuoteProstitutes are great

author: dfmischler
author_rank: Frequent Contributor
timestamp: October 02, 2013, 05:29:06 pm
content: I suggest you find something likethisthat suits your power outlets, voltages, etc. I don't think it matters if you buy, beg, borrow or steal it.

author: Tranan
author_rank: Contributor
timestamp: October 02, 2013, 05:41:17 pm
content: Quote from: dfmischler on October 02, 2013, 05:29:06 pmThats a good idea!Tanks!

author: G7PSK
author_rank: Super Contributor
timestamp: October 02, 2013, 05:44:21 pm
content: Quote from: Tranan on October 02, 2013, 05:01:14 pmThen the crane problem is not yours it's the suppliers of the crane, one less job for you.

author: Tranan
author_rank: Contributor
timestamp: October 02, 2013, 06:05:54 pm
content: Quote from: G7PSK on October 02, 2013, 05:44:21 pmHope so. I really do. but it depend if it the power supply or the motors on the crane.

author: madsci
author_rank: Regular Contributor
timestamp: October 03, 2013, 05:57:48 am
content: This sounds like fun...I'm serious!

author: metalphreak
author_rank: Frequent Contributor
timestamp: October 03, 2013, 01:17:35 pm
content: I've spent the last 9 months since graduating working as an electrical engineer for a building services consultancy.First thing you want to do is make a site wide single line diagram. This will have your main power distribution from the incoming power (HV/LV transformer, or utility feed in) to each switchboard (and how each switchboard feeds off another if cascaded that way).Second, make a schedule of circuits in each distribution board including breaker ratings (ie 3ph 250A breaker, 1ph 63A etc).Third, determine which loads/outlets are connected to each circuit.You need to work logically from the top down, rather than starting at the outlets, otherwise it'll be a nightmare.Hopefully the installer did at least some documentation. A list of circuits within the distribution panel door (sometimes in a plastic holder), labelling of circuit cables or outlets, has to be something otherwise it would have been hard to install in the first place!Once you have a proper schematic of the layout, you can begin to do load logging and see what is drawing power and how much. Tripping sounds like an undersized breaker or incorrect trip settings.It get's to be a lot more fun (and a bit of a nightmare) when you have to create proper 3D layouts in something like Revit

author: Tranan
author_rank: Contributor
timestamp: October 03, 2013, 08:27:36 pm
content: Quote from: metalphreak on October 03, 2013, 01:17:35 pmThank you! And I got a email that the board of director of the sight want a presentation of this when I am done. So "NO" pressure.

author: Phoenix
author_rank: Frequent Contributor
timestamp: October 04, 2013, 05:57:44 am
content: Quote from: Tranan on October 01, 2013, 08:58:05 pmI've done a similar project for dozens of exchanges. I was responsible for taking the electricians marked up drawings and putting them into CAD/simulation to do load and fault studies, CB ratings etc. I also visited several sites to confirm specific connection arrangements (things get very confusing when you start to include several layers of redundancy, change over switching, a dozen Gensets, UPSs, as you would get in a 15 story exchange building).Is it a factory style building with some offices? Or a multi-story building with electrical risers etc.? You may want to layout your drawing based on levels or major rooms. hopefully there are some drawings you can start from, and every DB should have a connection/CB schedule. One of the biggest problems with large exchanges/buildings is that contractors do their drawing for that specific part of the circuit only, and they are not reflected into any other drawing.I suggest you start from the main transformer and work your way out to the final DB's before tackling the power points and lights themselves.As for working out DB to DB connections if you have access to individual conductors you can use a clamp on current meter to measure the current at both ends of a wire and if they match it's a good indicator they are the same cable. Are you an electrician, allowed to take the covers off DBs etc? Or will you be able to get the help of one?

author: KJDS
author_rank: Super Contributor
timestamp: October 04, 2013, 10:30:32 am
content: Remember that the company will want you to succeed. You being there costs them money and if they are bringing in a new graduate then they should know that they are making an investment and the more effort they put into your mentoring the larger their reward will be.A good manager will only allow you to stray so far before guiding you back in the right direction and I'd be surprised if you're left for more than a couple of days without enough checking happening to ensure that you are going in the right direction. Were I the boss I'd define what I needed to be done to ensure a good result was achieved and ask you to define how you could achieve that. A day later we'd sit down and go through your plan and I may make suggestions to improve it if I thought that was necessary. Then I'd check on progress about once a day and provide what help was necessary to ensure success.Any manager that leaves a fresh graduate for five weeks without guidance is taking a significant risk.

author: metalphreak
author_rank: Frequent Contributor
timestamp: October 04, 2013, 01:06:53 pm
content: Don't forget most of these guys were graduates at one stage, so they know how much (or how little) practical knowledge you (don't) haveIt's normal to feel like you're expected to know everything, but you aren't. If in doubt, ask questions. Be at least a little bit prepared before you go and ask, like "this is how I was thinking of doing it, is there a better way to go about it?"

author: Tranan
author_rank: Contributor
timestamp: October 04, 2013, 11:12:03 pm
content: Quote from: KJDS on October 04, 2013, 10:30:32 amThank you.