I'm not sure if anyone can help me or not. I am currently in Honduras attempting to reopen a precious metal mine that is remote. I have a surplus US military 35 KW generator that will supply power for the site. The generator is setup to supply both single and 3 phase power.
the 3 phase is wired to a rock crusher and was tested in the US before being shipped so it is fine, however I want to use it to power lights, fans, and a couple sump pumps. It will be around 650 feet from the generator to the mine and I would like to run power to a sub panel at the mine entrance so I can run a couple circuit in the mine to light and ventilate or dry out when needed. I would hire an electrician here but am not impressed with their ability, if they ever hooked 2 wires together they are now electicians. I've seen service drops with multipule splices where the wire is just twisted together and sometimes wrapped with tape. I am not sure what size wire I need to run to the mine at that distance to maake that work so am looking for a little advice. I am obviously not a master electrician but feel I'm better qualified than the locals and want to make sure I dont get anyone hurt (self included). I have completely rewired my 1810 home and had a local US electrician friend check it out with no problems. Distance and location make that impossible and I can't ask him since he has passed away since then. If you could send advice on this please help me out. Thanks in advance.
assuming a 60A load at the subpanel and 5% Voltage drop, you'd need to run 1/0(#0) Copper, or 3/0(#000) AL for either 208 or 240V, if you have a 480V genset, you'll need # 3 Copper, or # 1 AL. for 3% V.D. at 208V you'll need 3/0(#000) CU or 300 KCMIL AL, 240V 3/0(#000) CU or 250KCMIL AL, 480V #1 CU, or #2/0(#00)AL
You can do this, we can help. I love this kind of project! To start with, we'll need a bit more technical information:
1: What are the output specs for the generator? Voltage, current, and configuration. By configuration, I mean is it 240V center-grounded delta, 120/208V wye, 480V delta with separate 120/208V single-phase, etc.
2: What are the specs for the rock crusher? Horsepower, kW, or volts/amps.
3: What equipment do you want to run at the mine? Need to know the voltage and current requirements.
There may have other voltage listed.
*= pretty rare in European area.( unless it is on some jobsite area then yeah it will show up )
Now before I can go more with information where ya locationed ? due there may have some rules or colour code may affect it in your area.
• How big rock crusher motour plus any convoyer motours.
• Ventalation motour size { this is pretty strict it have to be running all the time when any miners are working in the mine shaft }
• Lighting load. { just watchout with bulb requirement so just give you a head up on it }
Really for 650 feet IMO it will be easier to set the generator at 480 volt conferation and use the downstep transfomer to 208Y120 volts for general circuits.
The biggest killer is the voltage drop you will end up useing larger conductor if you set up on 120/240 or 208Y120 format.
mpoulton., just be aware that if you run both tri phase and single phase load you have really watch the rating espcally if run in delta format that is usealy the biggest curpit.
Some of the generators can run in double delta format but they are tricky to do it right if not heeded.
I spent a lot of time (24 years) working with and on generators in the military. I've never heard of a 35kW unit. What model is it? One of the MEP series? What is the NSN (will be on the nameplate).
Oh, and military generators also come in 400 Hz versions. These are primarily used in the Air Force.
First thanks everybody, The generator is 30 KW not 35 as orginally stated as noted by md2lgyk. Yes its the mep-005a utility which is 30KW, 3 phase, 4 wire, 120/208 and 240/416 volts. It is currently being shipped to me with the other equipment in a 40 foot container so I don't have the nsn at the moment. I was working last night after a 21 hour day so not at my best. I have the manuals for the generator on cd from emilitary manuals so after coming back to my residence I double checked and saw my mistake. The same is true about the electric motor I don't no the exact details on the motor since it is in the container also. The exhaust fans and lighting is not purchashed yet so I am open to Ideas. what I remember of the crusher motor is it 15hp 3 phase and during startup draws hard on the generator but once turning draws very little load even when crushing. The entrance to the mine is down over the side of the mountain from the work area and my road was almost triple that. The cost savings there alone is huge. If I can save more by going higher voltage amd transformer I am open to suggestions. I was hoping to get the wiring preplaced while the generator is in transit and that is what started this thread. I'm a 51 year old fat guy old fat guy on an adventure with a 26 year old local kid working with me. If it goes as good as the samples taken last year by myself and friends it may become a big time operation but for now its small time and on a tight budget. Why else would an old fat guy be climbing mts? As far as other loads I was looking at a couple halogen lights, a couple home type sump pumps and again I'm not sure about ventilation and will consider any advice you care to send, I'm only about 60 feet in so far. Again I thank everyone for there help.
Sounds like you have a handle on what you want to do. I work for a defense contractor so have access to a website to check what is the latest version of the TMs and get them for you if they're newer than what you have.
I admire your ambition. My wife and I built a log home entirely by ourselves when I was 60 years old, so I know how it is being old LOL.
I'd recommend sending power to the mine at 416V (delta) and using a transformer there to produce 120/240 as needed for loads. If the rock crusher can operate at 416V, that would be ideal. The maximum current will be 42A on each phase. The rock crusher may require up to about 30A of that. So, you have 12A or so available for the loads at the mine. That's 8640W. Of course, that assumes the crusher actually runs at 15HP - as you say, it's probably much less. So you might want to plan for about 20A capacity to the mine. Considering the length of the run (not just to the mine, but through it eventually), #8 wire would probably be a good choice. Three conductors plus ground should do. Then set a transformer and 3ph 120/208 panel at the mine.
You might consider making this an ungrounded system. Many industrial systems like this are ungrounded so that a single ground fault does not shut everything down instantly. A set of warning lamps indicates when a phase has a ground fault, and it can then be fixed at a convenient time. This also avoids equipment damage from a high current 416V fault to bonded metal. Ungrounded systems are a bit trickier to work with though, and require that you stay on top of them to keep them safe.
Thanks again to all. mpoulton thanks for the input about going ungrounded but to be honest the simpler the better for me. I will be doing this generally as a 1 man band so any labor savings helps. I hope to hire more than just the 1 local kid once we are up and running but at the moment it's not financialy prudent. I am a construction super that hasn't worked full time in the last 3 years so funds are tight. I've kept income coming jn doing odd jobs etc. till this oppurtunity came along, A friend offered it to me and I need to make it profitable.
md2lgyk thanks for the offer on the manuals and for the 24 yrs of service, I did 4 in the late 70's and I certainly appreciate what that kind of conotment takes and building a log cabin isn't an easy task. I helped a friend on the volunteer fire department do his and it was hard work no doubt about it.
frenchelectrician I am in the southern part of Honduras. The minr is 7 miles off the main road and takes an hour to drive to so it isn't in any place I could call a town or region. and I'm sorry I can't put a definite load to work with as I noted in my previous posts. I do apreciate you help anyhow.
When I can supply more detailed information I will again I thank all who contribute
I'm guessing you've never been to Honduras. I have, and suspect they have no such organization. Pretty primitive place.
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