# Military Electrician Needing Help on Developing Install



## SeabeeElectrician (May 14, 2020)

Hello all,

For those of you who are unfamiliar with the Seabees, we're US Navy general construction (and a ton of other stuff baked in). I've been an electrician in the Seabees for a decade, but that definitely doesn't mean I have 10 years' equivalent electrical experience compared to civilian sparkies because we spend so much time with the "other" stuff.

I'm set to deploy overseas to do an install and I do not have design specs - this is common in my field, but I don't have the training/skillset to make sure I'm doing this right so I'd appreciate some help. In the past I've come here for help when I'm in some oddball country and stuck and you folks have been a huge help. 



@Dennis Alwon *I made a new account because my last one had some identifying information on it, so I wanted to start fresh. I've made a photo album of my plan to help walk through what I've got, but I am blocked from posting it because this is a new account. I sent an email to website contact requesting my post limit be removed, can I have a mod do that please? It would really help explain what I've got here.*


-Job is to *install eight new dwelling units* that are built into ISO Shipping containers. I don't have their specs, but *each ISO has a 50A 120v service connection* (OCPD/disconnect of some kind, or *perhaps just a tie-in*). Each ISO has two rooms, each with a window AC unit, convenience outlets, and lights.


-I've been told to *connect the eight ISOs to two 100A subs with 4x50A CBs in each*. There will be *four ISOs connected to each 100A sub.
*

-*My panel is anywhere from 250'-400' away from where the subs will sit*. I haven't seen the site in person and I'm estimating based on satellite data of the area; so *250' is my short run trench path and 400' is my worst case path*.


-*Panel is 400A 120/208 fused disconnected service point for the camp*. There's room for some more 100A or 200A breakers.


So the layout for how they wanted me to run this was essentially a napkin drawing with "put in a new 200A 120v breaker and something something dashed line to the ISOs 100A subs and make electrical stuff happen." The area I'm getting materials from probably doesn't have any availability of CBs with double lugs, or feed-through lugs (This is a very very small and isolated country in the middle of the ocean), so I'm planning to work with a design that goes off of two 100A breakers instead of a single 200A.

My plan is to run an underground set of two feeders in sch80 PVC, but I'm not sure how to size the conductors - the voltage drop for a 400' run is significant, but I'm not sure I'm doing the calculations right, I've never had to before. 

I'm pretty sure the NEC would classify these as feeders, right? The utility connection is just this one panel, everything else on the camp is fed from it. I'm using article 215.

I also don't know how to select the correct 100A subs for this work. Do they need fuses, or disconnects?

This is kind of embarrassing to ask all of this, but the reality is that Seabees aren't trained to plan installs, just conduct them in accordance with applicable standards once someone tells us what to install. But I've been put in a (not unusual at all) situation where I'm told to "figure it out." Normally I can figure it out with some good reading but in this case I'm stuck.

ALSO - if anyone thinks this plan is dumb and there's a better way, please let me know. I am not married to a plan with two subs, or two sets of underground ductwork, etc.


Thank you so much for the help!


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## paulengr (Oct 8, 2017)

Set it up like an RV or mobile home park because that’s very close to what you are describing.


Sent from my iPhone using Tapatalk


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## Dennis Alwon (May 9, 2009)

Mods can only control limited account info... I am not sure that the limit can be lifted for one person anyway... sorry.

I can't believe they would send you over there to do a job that you are not trained to do. Isn't someone else there that can help? 

*200 amp breaker at 120V ????? What is that?*

You can't tie two 100 amp breakers together and get 200 amps unless you mean have 2- separate 100 amp breakers feeding different areas.


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## Kevin (Feb 14, 2017)

@SeabeeElectrician if you email me the photos, I can post them for you. My email address will be removed in 2 hours.

EDIT: link for photos.


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## Bird dog (Oct 27, 2015)

Dennis Alwon said:


> I can't believe they would send you over there to do a job that you are not trained to do. Isn't someone else there that can help?


You would be surprised to gobsmacked as to the training/equipment. :sad:


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## SeabeeElectrician (May 14, 2020)

Kevin_Essiambre said:


> @*SeabeeElectrician* if you email me the photos, I can post them for you. My email address will be removed in 2 hours.
> 
> Sent from my new phone. Autocorrect may have changed stuff.



Link sent. Thank you!


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## SeabeeElectrician (May 14, 2020)

I'm sorry, this means nothing to me. All the work I've done has been related to new installs or renovations on military bases, or doing work in 3rd world countries to improve rural infrastructure for local populations.


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## SeabeeElectrician (May 14, 2020)

SeabeeElectrician said:


> I'm sorry, this means nothing to me. All the work I've done has been related to new installs or renovations on military bases, or doing work in 3rd world countries to improve rural infrastructure for local populations.



sorry, this reply was meant for:





> Set it up like an RV or mobile home park because that’s very close to what you are describing.
> 
> 
> Sent from my iPhone using Tapatalk



Don't think I can edit posts yet.


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## SeabeeElectrician (May 14, 2020)

Dennis Alwon said:


> Mods can only control limited account info... I am not sure that the limit can be lifted for one person anyway... sorry.
> 
> I can't believe they would send you over there to do a job that you are not trained to do. Isn't someone else there that can help?
> 
> ...



There is no training in the Navy for this. There is no other person to help, I am "the guy." Honestly I'm pretty knowledgeable compared to most of my peers because I'm good at reading references, but we do so little actual electrical work in our careers and we just learn from each other, not trade professionals - so it's a bunch of the blind leading the blind. Real talk it's kind of scary, but that's why I'm seeking some help - because this install WILL happen one way or another and I want it to be safe.



I didn't mean tie two 100A breakers together to get 200A, I was saying that it is possible to feed two 100A subs off of one breaker if you have the right CB, or so I thought. It's moot anyways because that won't be available where I'm going. 



The service panel is 120/208 and I need it to feed two 100A subs (per the plan I was given, but I'm trying to submit design changes because I'm 99% sure the "plan" I was given was from someone who isn't even an electrician in the first place).


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## Kevin (Feb 14, 2017)

here is a link for his photos.

Sent from my new phone. Autocorrect may have changed stuff.


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## SeabeeElectrician (May 14, 2020)

Bird dog said:


> You would be surprised to gobsmacked as to the training/equipment. :sad:



To be fair, we have pretty good training - the problem is we don't just focus on electrical, there's construction planning, project management, finances, weapons, convoy tactics, chemical/biological/radiological defense and response, heavy equipment operation, vertical construction (carpentry/masonry), plumbing, logistics, first aid.... 



And then on top of that you've got all the other paperwork that goes with any large organization. Our bandwidth for any specific thing is so low we get minimal training in most areas. We get the most direct training in our actual jobs, but over my entire career I think I've had maybe seven months' total of electrical training? The rest is OJT (blind leading the blind), and we only work an actual site with electrical maybe once or twice per 18 month period on average.


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## cuba_pete (Dec 8, 2011)

*Say what, brother???*



SeabeeElectrician said:


> There is no training in the Navy for this.


A qualified Construction Electrician would find this a very shady thing to say.

For those who don't know, Construction Electrician (CE NOS H110) is a Seabee source rating for "electrician" in the outside world.

my 2p


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## cuba_pete (Dec 8, 2011)

SeabeeElectrician said:


> To be fair... (blind leading the blind)...


wow...just...wow:surprise:

This isn't really true...they are obviously on the shady side of the tree

*My no BS source*


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## SeabeeElectrician (May 14, 2020)

cuba_pete said:


> wow...just...wow:surprise:
> 
> This isn't really true...they are obviously on the shady side of the tree
> 
> _My no BS source_



The career LaDR is your source on me being shady?


No offense, but you don't really know what you're talking about so I'd appreciate if you wouldn't derail this thread.


We get rate(job - in the case electrician) training. There's A-School, and various C schools and I've had the pleasure of going to those. But there is no training that directly correlates to the problem in my OP. 



I would know, it's my job.


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## cuba_pete (Dec 8, 2011)

SeabeeElectrician said:


> The career LaDR is your source on me being shady?
> 
> 
> No offense, but you don't really know what you're talking about so I'd appreciate if you wouldn't derail this thread.
> ...


I've been with the Navy as an electrician for nearly 35 years, jackass. I'm a facility engineer, now...so I get to help the electricians who work for me, including EM's and CE's.

Find a *QUALIFIED ELECTRICIAN* instead of reaching out to a civilian populace, throwing shade on your little bit of training that you so desperately need.

Your OP stinks to high heaven.

*WHO IS YOUR MASTER CHIEF or Senior Enlisted Adviser???*

*I need to have a talk with your ROICC as well...*

*NAMES AND NUMBERS, shipmate!*


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## SeabeeElectrician (May 14, 2020)

cuba_pete said:


> I've been with the Navy as an electrician for nearly 35 years, jackass. I'm a facility engineer, now...so I get to help the electricians who work for me, including EM's and CE's.
> 
> Find a *QUALIFIED ELECTRICIAN* instead of reaching out to a civilian populace, throwing shade on your little bit of training that you so desperately need.
> 
> ...



There's no shade on the training I've received. I made it clear that we get good training, it's just too varied and it can't/doesn't prepare us for every situation. 



I like to use ALL resources available (DoD AND civilian) instead of letting my ego get in the way of A) admitting that this is beyond my current capabilities or B) admitting that my community does NOT do a good job training enlisted CEs how to properly size services or feeders, nor how to ensure we're selecting correct OCPD for ANY installs. It's _ok _to admit the training gaps we have.



We are taught WIRING METHODS at all points in our careers because the general assumption is that we're given incredibly detailed drawings and RFI everything under the sun. This is a FACT.



You are in a position that is far removed from the reality at the deckplates. You can throw your _own _shade all you want, you will not change my mind nor change the fact that I will continue to periodically seek civilian professional resources for assistance (with the understanding that I take nothing from an online forum without triple checking through other means that it is reliable information).


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## Bird dog (Oct 27, 2015)

SeabeeElectrician said:


> I'm sorry, this means nothing to me. All the work I've done has been related to new installs or renovations on military bases, or doing work in 3rd world countries to improve rural infrastructure for local populations.


Get with your base electricians to lay this out with you. They also can explain why they designed it the way they did. You're way in over your head.


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## Wirenuting (Sep 12, 2010)

SeabeeElectrician said:


> There's no shade on the training I've received. I made it clear that we get good training, it's just too varied and it can't/doesn't prepare us for every situation.
> 
> 
> 
> ...


Please contact your nearest NAVFAC command. 
We will assist and guide you towards the information you need for the area your deploying to. You didn't say what coast your at so I'll guess and say Norfolk. So NAVFAC MIDLANT would be a starting point. I'm sure there is a Contract Rep or OIC there able to help. 
Please don't post plans here on ET


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## CoolWill (Jan 5, 2019)

4/0 copper would get you 400 feet with less than 3% voltage drop for 100 amps at 208 V.


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## MHElectric (Oct 14, 2011)

Dennis Alwon said:


> I can't believe they would send you over there to do a job that you are not trained to do. Isn't someone else there that can help?


Lol! Welcome to the US military. 

None of us were ever really "trained or qualified". We just enlisted and they turned us into soldiers/sailors/airmen/marines/coast guards. Young, dumb and full of testosterone. Hold your chin up, stick your chest out and GO DO IT! 

God bless the USA and all those that serve.


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## stiffneck (Nov 8, 2015)

This is exactly how some Airport Electric Shops  are run. Which is why airports tend to be "contractor $$ heaven".


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## SeabeeElectrician (May 14, 2020)

Wirenuting said:


> Please contact your nearest NAVFAC command.
> We will assist and guide you towards the information you need for the area your deploying to. You didn't say what coast your at so I'll guess and say Norfolk. So NAVFAC MIDLANT would be a starting point. I'm sure there is a Contract Rep or OIC there able to help.
> Please don't post plans here on ET



Thank you for the guidance. For the record, any images I posted here are in no way plans, just a visual representation of what my current ideas about this install are. There are no plans, just a task.



NAVFAC is a good resource but I'd like to beat my head against the table first, then escalate. Right now it's tricky given current restrictions due to COVID-19. I have come to value this forum as a collaborative resource - and I'd like to see if there are suggestions on a better way to run this in general than what I have here. 





CoolWill said:


> 4/0 copper would get you 400 feet with less than 3% voltage drop for 100 amps at 208 V.



Thank you - when I did my math I was coming up with a value of .0006 ohms/kFT, which I knew was outrageous, but I was using the VD formula incorrectly (was going by a percentage of voltage drop instead of actual voltage drop, in volts... if that makes sense.)


@Dennis Alwon, will you do me a favor and delete this thread? I think the discussion has strayed too far from the OP, and too many feathers have gotten rustled.


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## Wirenuting (Sep 12, 2010)

SeabeeElectrician said:


> Thank you for the guidance. For the record, any images I posted here are in no way plans, just a visual representation of what my current ideas about this install are. There are no plans, just a task.
> 
> 
> 
> ...


Seabees walk in our shops all the time and we always help them out. 
It’s the self help crew we chase away. Deploying assets always get head of the line privilege. 
You can still get answers here at ET and your questions are welcome. 
Cuba Pete is a very knowledgeable person, after his coffee that is.


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## varmit (Apr 19, 2009)

I appreciate the challenge that you have been assigned. From reading your description, hear is my advice.

From your main panel, install two feeders of either (3) 3/0 copper or 250 aluminum and a #4 ground to a 200 amp main lug panel. ( One feeder to each panel.) The 200 amp panel will have lugs to accommodate the larger wires ran to avoid any excessive voltage drop. I assume that there is no cooking facilities in these units? If not, the total connected load is probably only around 30 to 35 amps for each unit. It would be better for load balancing, to install these circuits as 208/120 to each unit. This would allow you to use standard NEMA (US) panel and breaker materials.

For the circuits to each unit, if the distance is not excessive, I would suggest (3) #6 copper or #4 aluminum, either with a #10 copper ground wire. 

The panel in each unit would be considered a sub panel by US codes and would require, if powered at 208/120, (2) energized (hot) conductors, (1) grounded (neutral) conductor, and (1) grounding conductor. 

There are a few more grounding/bonding details that would be determined by the local soil conditions.

If I can be any further help, please let me know.


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## SeabeeElectrician (May 14, 2020)

Wirenuting said:


> Seabees walk in our shops all the time and we always help them out.
> It’s the self help crew we chase away. Deploying assets always get head of the line privilege.
> You can still get answers here at ET and your questions are welcome.
> Cuba Pete is a very knowledgeable person, after his coffee that is.



Thanks! I definitely didn't mean to talk poorly about the Navy that I love, if that's how it came off. When I use the term "blind leading the blind" what I mean is that we are all learn from each other, and a lot of information and techniques get passed around, some better than others. Sometimes we end up doing things a really difficult way because we just don't know that there's a tool or material that is specifically designed for what we're trying to achieve, because we just haven't had exposure to it. That's the reason why I make sure to bounce things off of places like ET.


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## Wirenuting (Sep 12, 2010)

SeabeeElectrician said:


> Thanks! I definitely didn't mean to talk poorly about the Navy that I love, if that's how it came off. When I use the term "blind leading the blind" what I mean is that we are all learn from each other, and a lot of information and techniques get passed around, some better than others. Sometimes we end up doing things a really difficult way because we just don't know that there's a tool or material that is specifically designed for what we're trying to achieve, because we just haven't had exposure to it. That's the reason why I make sure to bounce things off of places like ET.


Nothing wrong about a good sea story. 
Like the time we located some 4160v underground so ur local Seabee unit could install power for a building. 
Sadly they thought the red paint on the ground ment “Trench Here”, all 100 yards worth.


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## MechanicalDVR (Dec 29, 2007)

Seems to me I've seen several of these container set-ups from companies such as WillScot on various military facilities.

Inlet on exterior and a 60 amp 6 circuit circuit panel inside. (1) Lighting, (2) receptacle, (2) a/c, (1) spare 20 amp circuits.

Single room unit w/4 circuit panel and a/c unit with inlet.


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## Bird dog (Oct 27, 2015)

MechanicalDVR said:


> Seems to me I've seen several of these container set-ups from companies such as WillScot on various military facilities.
> 
> Inlet on exterior and a 60 amp 6 circuit circuit panel inside. (1) Lighting, (2) receptacle, (2) a/c, (1) spare 20 amp circuits.
> 
> Single room unit w/4 circuit panel and a/c unit with inlet.


 Maybe talking to Navy power production & distribution would help. Feed everything like communication vans. Cables may already be available with plugs or buy COTS (Commercial Off The Shelf).
Driving ground rods is going to be a bear if going to the Middle East.

Why does your 400amp panel have to be so far away? Is this existing power or a generator set? Can you move the generator closer or move the containers closer to the existing panel?


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## SeabeeElectrician (May 14, 2020)

Bird dog said:


> Maybe talking to Navy power production & distribution would help. Feed everything like communication vans. Cables may already be available with plugs or or COTS (Commercial Off The Shelf).
> 
> 
> Why does your 400amp panel have to be so far away? Is this existing power or a generator set? Can you move the generator closer or move the containers closer to the existing panel?



It's where the panel is, can't help it. 400' is my worst case, It could be more around 250-275', but it depends on how we have to run it once we see the site. That's a really big variance and I believe it's somewhere closer to 300' in reality, but looking at imagery only tells so much.


The dwellings themselves aren't anything extraordinary; lights, ACs, and convenience receptacles. I don't have specs on what they actually are, just that they need 50A service.


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## Bird dog (Oct 27, 2015)

SeabeeElectrician said:


> It's where the panel is, can't help it. 400' is my worst case, It could be more around 250-275', but it depends on how we have to run it once we see the site. That's a really big variance and I believe it's somewhere closer to 300' in reality, but looking at imagery only tells so much.
> 
> 
> The dwellings themselves aren't anything extraordinary; lights, ACs, and convenience receptacles. I don't have specs on what they actually are, just that they need 50A service.


You know there is a 400amp panel in working order? Someone is at the site. Someone can contact them.


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## SeabeeElectrician (May 14, 2020)

varmit said:


> I appreciate the challenge that you have been assigned. From reading your description, hear is my advice.
> 
> From your main panel, install two feeders of either (3) 3/0 copper or 250 aluminum and a #4 ground to a 200 amp main lug panel. ( One feeder to each panel.)



I'm a bit confused. Are you suggesting using parallel sets of 3/0 and a single 200A sub? You say "One feeder to each panel," but if I ran out to a 200A sub I would only need a single one. Also, when I do a VD calculation for parallel sets at [email protected] at 400' I get 4/0, not 3/0. Am I off?




varmit said:


> I assume that there is no cooking facilities in these units?



There is not, just lights, ACs, and convenience receptacles.





varmit said:


> If I can be any further help, please let me know.



Thank you kindly.


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## SeabeeElectrician (May 14, 2020)

Bird dog said:


> You know there is a 400amp panel in working order? Someone is at the site. Someone can contact them.



The dwellings themselves aren't there yet. I'm working on getting their specs currently, but the jury is still out. 



Or are you talking about the distance? We won't know until we break ground and see what's buried already. Hard to explain without divulging more about the area than I'd care to, but I will either try to wait until we get there to purchase the conductors if possible, or just play it safe and go with a 400' estimate for sizing them if I have to.


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## Bird dog (Oct 27, 2015)

SeabeeElectrician said:


> The dwellings themselves aren't there yet. I'm working on getting their specs currently, but the jury is still out.
> 
> 
> 
> Or are you talking about the distance? We won't know until we break ground and see what's buried already. Hard to explain without divulging more about the area than I'd care to, but I will either try to wait until we get there to purchase the conductors if possible, or just play it safe and go with a 400' estimate for sizing them if I have to.


Go with the 400' & take it with you. Make sure the lugs will take the wire size. No, don't be cutting out wire strands. Don't plan on buying anything in country.


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## jbfan (Jan 22, 2007)

When I was in AIT, in 1980, we had SeeBees in class with us for signal. Cool guys that had beards while in uniform!

I know it was OT, but I had nothing else to add to the thread!


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## cuba_pete (Dec 8, 2011)

Wirenuting said:


> Cuba Pete is a very knowledgeable person, after his coffee that is.


Thanks man...sniff...beautiful. I’ve been drinking this Moose-Munch my wife got for her Mother’s Day...it makes me calm. 


SeabeeElectrician said:


> Thanks! I definitely didn't mean to talk poorly about the Navy...I make sure to bounce things off of places like ET


Okay, okay...I‘ll simma down. You’re exactly right...this place is where I go for knowledge as well, obviously. One thing I tell the worker bee deck plates is never take anything I say seriously...my bark is just that. I’m actually a very mean guy, but not really...just a d***.



MechanicalDVR said:


> Seems to me I've seen several of these container set-ups from companies such as WillScot...


Yeah, we were going to put three or four in my compound last year and our FMS was like...find me some power. I did, but it’s always like...do this. I love my FMS. We have these portables all over the base, leased out for this and that...like $30G per, something like that. Funny thing is, they’re exactly as you expect...like working out of a sea-land crate.

Cheers


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## MechanicalDVR (Dec 29, 2007)

cuba_pete said:


> Yeah, we were going to put three or four in my compound last year and our FMS was like...find me some power. I did, but it’s always like...do this. I love my FMS. We have these portables all over the base, leased out for this and that...like $30G per, something like that. Funny thing is, they’re exactly as you expect...like working out of a sea-land crate.
> 
> Cheers


Do a lot of military/government work for a family business and EVERY facility I've been on has every variation of them you can think of, from singles to stacked with prefab metal stairs.

Wired up York thru the wall packaged heat pumps to a few a couple years back up in PA.


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## varmit (Apr 19, 2009)

SeabeeElectrician said:


> I'm a bit confused. Are you suggesting using parallel sets of 3/0 and a single 200A sub? You say "One feeder to each panel," but if I ran out to a 200A sub I would only need a single one. Also, when I do a VD calculation for parallel sets at [email protected] at 400' I get 4/0, not 3/0. Am I off?
> 
> 
> 
> ...


There would be two separate circuits from the 400 amp service. Each circuit would go to one of the two 200 amp panels. The voltage drop at 400 feet is about 4%. Using two panels allows the panels to be located to where the length, of the circuits to each building unit, can be less. The breakers, in the 400 amp panel, feeding the 200 amp panels, do not need to be 200 amp, as the connected load is way less than 200 amp. Probably, a 125 or 150 amp breaker will have lugs large enough to fit the 3/0 or 250 wire used to feed the 200 amp rated panel. 

If you only used one 200 amp panel, the wire size to compensate for voltage drop on the feeder at 400 feet, would be too large to fit the panel lugs on the 200 amp panel without doing more work and requiring more material. 

I would think that getting all of the material delivered to the site is on of the major challenges? 

It is all a matter of sizing the circuits to handle the connected loads and sizing the equipment to physically fit the wire and lug connections without needing odd and hard to obtain parts.


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## Easy (Oct 18, 2017)

MHElectric said:


> Lol! Welcome to the US military.
> 
> None of us were ever really "trained or qualified". We just enlisted and they turned us into soldiers/sailors/airmen/marines/coast guards. Young, dumb and full of testosterone. Hold your chin up, stick your chest out and GO DO IT!
> 
> God bless the USA and all those that serve.


It's nice to know that some of the members have compassion for those who serve our country. I have never served but I greatly respect the men and women who serve and have served throughout history.
I'm guessing that this poor guy has no one to go to for help and is reaching out to us. 

Coolwill provided some useful information and I commend him for that. Your statement is most likely true and also helpful.

My only input for this poor guy is that voltage drop is not such a bad thing for temporary living quarters made out of shipping containers. Whats the worse that can happen if the voltage is a bit low. The electric blankets might not get as hot or lights might not shine as bright. I would be more concerned with grounding and bonding. Maybe GFCI's and stuff that might help from a safety aspect. 

Who knows what resources this guy has for electrical information. Our navy is quite large and some guys might have great resources to gather knowledge and some may have very little.


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## Bird dog (Oct 27, 2015)

Easy said:


> My only input for this poor guy is that voltage drop is not such a bad thing for temporary living quarters made out of shipping containers. Whats the worse that can happen if the voltage is a bit low. The electric blankets might not get as hot or lights might not shine as bright.


He'll have AC units, so, he does need to calculate voltage drop. If the voltage drop is too great will the GFIs work properly?


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## splatz (May 23, 2015)

The Southwire voltage drop calculator is probably not approved for use by the US armed services, but you can cheat with it and do the calculation by hand to verify. 

https://www.southwire.com/calculator-vdrop

I think you have to think the voltage drop through in two steps, from the main panel to the subs, then again from the subs to the containers. It's additive / cumulative. 

You also have to consider how reliable your supply voltage is, if it's already a few percent below what it should be, you could have a headache. 

Don't forget you don't necessarily have to figure your voltage drop on the full capacity of the system, just the actual load. 

If you want to complicate your life and spend more money, which if I understand correctly is the Navy Way, you could consider using transformers to work around the distances. If you choose the right transformers you have some flexibility, you can tap them a little higher or lower and get nice even operating voltage in all the shacks even if they are at greatly different distances. 

If you want to simplify your life, keep in mind there are pin terminals available that let you use big wires in little lugs. This is not crazy, it's for your exact situation, when the ampacities would allow much smaller wires but you oversize for voltage drop. 










And lastly, it may be a waste but may bear fruit, read through the feeder tap rules and see if there's anything in there that lets you get creative and save some trouble.


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## MHElectric (Oct 14, 2011)

It's actually pretty interesting that this guy gets to work on stuff over there. 

When I was in Iraq, we had just invaded. All the living conditions were in buildings that had been taken. We all just slept on cots. All the lights and electricity was supplied by generators for each company or platoon. You would pull duty every so many days to work check the fuel level and top it off for 6-12hrs or so. Eventually a small power station was brought into our compound, but that was at the tail end and we were getting ready to leave. 

The shower/latrine areas were a one-peice trailer that had some type of power hitched up to it. I remember that if you would touch the handle to the door and be standing on the metal stairs, it would shock the mess out of you! You had to use your rubber shower sandal to open the door. It seemed like nobody would ever tell the new guys that - they just made them figure it out on their own!


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## Bird dog (Oct 27, 2015)

splatz said:


> If you want to simplify your life, keep in mind there are pin terminals available that let you use big wires in little lugs. This is not crazy, it's for your exact situation, when the ampacities would allow much smaller wires but you oversize for voltage drop.
> 
> 
> 
> ...


 This may sound like a dumb question, but, can these be used on SO, DLO cable or welding cable (fine wire)? I'm sure it wouldn't be a problem with building wire (THWN for wet location, buried conduit).


Edit for the OP...You will need to buy a specific crimper that will fit these. I don't know which one. No way around this. They may be manufacturer specific that is our connectors must use this crimper & die (insert). 
@splatz spec sheet does show DLO size & crimp size.
https://hubbellcdn.com/specsheet/Burndy_AYPO40_Specsheet.pdf


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## Wirenuting (Sep 12, 2010)

MHElectric said:


> It's actually pretty interesting that this guy gets to work on stuff over there.
> 
> The shower/latrine areas were a one-peice trailer that had some type of power hitched up to it. I remember that if you would touch the handle to the door and be standing on the metal stairs, it would shock the mess out of you! You had to use your rubber shower sandal to open the door. It seemed like nobody would ever tell the new guys that - they just made them figure it out on their own!


There was a big stink about that for years afterwards. They asked for volunteers to go over and fix it. 
Some of it turned out to be local contractors at fault. 
We still see job postings for temp duty overseas to catch that stuff. 

But that was the first thing that hit my mind when I saw the original post.


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## MHElectric (Oct 14, 2011)

Wirenuting said:


> There was a big stink about that for years afterwards. They asked for volunteers to go over and fix it.
> Some of it turned out to be local contractors at fault.
> We still see job postings for temp duty overseas to catch that stuff.
> 
> But that was the first thing that hit my mind when I saw the original post.


I believe it was *ALL* local contractors at that time. This was '03-'04.

And yes, I remember hearing about it on the news _years_ after I had gotten out, that there were a few civilian and military deaths linked to it. Very sad.


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## splatz (May 23, 2015)

Bird dog said:


> This may sound like a dumb question, but, can these be used on SO, DLO cable or welding cable (fine wire)? I'm sure it wouldn't be a problem with building wire (THWN for wet location, buried conduit).
> 
> 
> Edit for the OP...You will need to buy a specific crimper that will fit these. I don't know which one. No way around this. They may be manufacturer specific that is our connectors must use this crimper & die (insert).
> ...


Both good points!


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## Easy (Oct 18, 2017)

Bird dog said:


> He'll have AC units, so, he does need to calculate voltage drop. If the voltage drop is too great will the GFIs work properly?


The AC units should work fine but might not last as long. The GFCI's, would positively function. I've tested some at 90 volts and they still test out ok. I don't think that the gondolas will be permanent housing for anyone. It's not like the guy is building a command and control center.


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## Bird dog (Oct 27, 2015)

Easy said:


> The AC units should work fine but might not last as long. The GFCI's, would positively function. I've tested some at 90 volts and they still test out ok.* I don't think that the gondolas will be permanent housing for anyone*. It's not like the guy is building a command and control center.


Not for any one person, but, the military could use it for 10-15 years or more.


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## SeabeeElectrician (May 14, 2020)

varmit said:


> There would be two separate circuits from the 400 amp service. Each circuit would go to one of the two 200 amp panels. The voltage drop at 400 feet is about 4%. Using two panels allows the panels to be located to where the length, of the circuits to each building unit, can be less. The breakers, in the 400 amp panel, feeding the 200 amp panels, do not need to be 200 amp, as the connected load is way less than 200 amp. Probably, a 125 or 150 amp breaker will have lugs large enough to fit the 3/0 or 250 wire used to feed the 200 amp rated panel.
> 
> If you only used one 200 amp panel, the wire size to compensate for voltage drop on the feeder at 400 feet, would be too large to fit the panel lugs on the 200 amp panel without doing more work and requiring more material.
> 
> ...



I understand what you're saying now. Sizing the sub lugs properly is a major factor, yes. I know a single 400' feeder would mean I need a much bigger wire size than I want, which is why I was thinking you might have been talking parallel sets. 



I'm not sure exactly what materials are available - I intend to call out my minimum specifications for amperage/voltage, lug size, and breaker capacity. If supply can procure panels with the correct lug size at 100A then that's best, but if we have to go with 200 that's ok too. Is a 100A panel that can take 3/0 or 4/0 service uncommon? I won't be using any aluminum.



Getting materials delivered is a whole different ball of wax that I have to unravel, but it's ok. I do not think I'll have availability of odd/weird parts at all, but as long as I'm solid on my minimum specifications I won't have any issues.


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## SeabeeElectrician (May 14, 2020)

splatz said:


> The Southwire voltage drop calculator is probably not approved for use by the US armed services, but you can cheat with it and do the calculation by hand to verify.
> 
> southwire voltage drop.com



It's not, but I do the math by hand and then verify it with online calculators; southwire is my preferred in this case because it lets me use variables that fit my specific situation.





splatz said:


> I think you have to think the voltage drop through in two steps, from the main panel to the subs, then again from the subs to the containers. It's additive / cumulative.



The containers are right by the subs, so any drop after the subs will be minimal. I am targeting maximum 4% at the subs, and with any extra one or two dozen feet and other losses I might see total losses of 5%. I'd like to keep it 4% max, however, so I'm shooting for max 3% drop over the 400'.







splatz said:


> You also have to consider how reliable your supply voltage is, if it's already a few percent below what it should be, you could have a headache.



This... I had not thought of that. I'm going to see if I can get someone on the ground to give me an actual voltage reading at the service point. 





splatz said:


> If you want to complicate your life and spend more money, which if I understand correctly is the Navy Way, you could consider using transformers to work around the distances. If you choose the right transformers you have some flexibility, you can tap them a little higher or lower and get nice even operating voltage in all the shacks even if they are at greatly different distances.



This is actually the course of action I originally wanted to pursue, but we have time/manpower constraints that will put this out of scope.




splatz said:


> If you want to simplify your life, keep in mind there are pin terminals available that let you use big wires in little lugs. This is not crazy, it's for your exact situation, when the ampacities would allow much smaller wires but you oversize for voltage drop.



These would be great! Are these usually a crimp/bolt type, or are they exothermic, or what? 




splatz said:


> And lastly, it may be a waste but may bear fruit, read through the feeder tap rules and see if there's anything in there that lets you get creative and save some trouble.



I will look into it, thank you.


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## SeabeeElectrician (May 14, 2020)

Wirenuting said:


> There was a big stink about that for years afterwards. They asked for volunteers to go over and fix it.
> Some of it turned out to be local contractors at fault.
> We still see job postings for temp duty overseas to catch that stuff.
> 
> But that was the first thing that hit my mind when I saw the original post.



I first joined at the tail end of Afghanistan and my first job sites were there. We always did the best we could with what we had, but often we didn't have the right materials and jury-rigged stuff, or we didn't have the knowledge and did the wrong thing out of ignorance. 



It wouldn't surprise me that some of the work done over there led to deaths. It's truly a shame. I'll say that the contractors I worked with though were always great; the ones I worked with were a godsend, but I'm sure there were plenty of scumbags who just wanted the fat checks.


Last thing I want is crappy work in my rear-view.


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## SeabeeElectrician (May 14, 2020)

Easy said:


> The AC units should work fine but might not last as long. The GFCI's, would positively function. I've tested some at 90 volts and they still test out ok. I don't think that the gondolas will be permanent housing for anyone. It's not like the guy is building a command and control center.





Bird dog said:


> Not for any one person, but, the military could use it for 10-15 years or more.



I anticipate these will see continuous use for at least a decade.


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## splatz (May 23, 2015)

SeabeeElectrician said:


> These would be great! Are these usually a crimp/bolt type, or are they exothermic, or what?


They are crimp on, Burndy, NSI, etc. make them, you'll find one linked in @Bird dog 's post above.


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## CoolWill (Jan 5, 2019)

Run the 4/0 into a gutter over the panels and change wire size to fit the lugs. Insulated Polaris taps. All standard equipment off the shelf.


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## cuba_pete (Dec 8, 2011)

Wirenuting said:


> Some of it turned out to be local contractors at fault. We still see job postings for temp duty overseas to catch that stuff.


So, Halliburton had subbed this out to Brown and Root (which hire "local" ahem...Third Country Nationals...where I was stationed and they had hooked up some temporary panelboards under a rickety shelter made from plywood sheathing and 2x4's. Then the CO was like, they need washers, dryers, stoves, refrigerators in that hooch over there...make it happen.

I didn't want to go near that service area...I was just like...give me some feeders in a trench, tag it out (which I double checked...carefully) and leave me be for a while. I told the guards to be sure and let me know if any contractors entered the compound...so positive control on entry was a saving grace.



MHElectric said:


> I believe it was *ALL* local contractors at that time. This was '03-'04


Into '05 and '06 by my experience. ...and military leadership always gets some of the blame.



Easy said:


> The AC units should work fine but might not last as long. I don't think that the gondolas will be permanent housing for anyone. It's not like the guy is building a command and control center.


btw...we used the 240 VAC AC window units, they seemed to fare better under the low voltage conditions, just lower air flow but at least it was chilly.

You might be surprised by what the hooches get used for. We had some "interview" rooms, psyops, intel, escort control, etc. all had working quarters in the same types of structures as our guests (without the extra hardware).:wink:

Anything silver oak leafs and higher got a real building.



SeabeeElectrician said:


> It wouldn't surprise me that some of the work done over there led to deaths. ...I'm sure there were plenty of scumbags who just wanted the fat checks.


Those checks were so fat for the TCN contractors that one month's pay was likely a year's pay or more for some of them back home.

=======================

I worked with the ACE which, admittedly, did seem to have a better level of training for their senior electricians (MOS?). Their junior electricians? Not so much...I had a plumber helping me out most of the time and they took better direction. Then I had to help them with their job too...never again, please.


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## SeabeeElectrician (May 14, 2020)

CoolWill said:


> Run the 4/0 into a gutter over the panels and change wire size to fit the lugs. Insulated Polaris taps. All standard equipment off the shelf.



I think in this case two pull boxes will be appropriate vs a single trough. I've never used polaris taps but looking them up they will do quite nicely to bring the conductor size down to something more appropriate for 100A lugs. Thank you.


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## telsa (May 22, 2015)

The CBs are NOT going to be held to the NEC voltage drop specs. These are essentially temporary facilities for surge needs. 

It smells like these will be used for the Wuhan virus -- as isolation quarters.

Such instant quarters are springing up all over the nation.

I've built three such units -- strictly as job boxes -- with a 50A inlet -- California style -- and a dinky NEMA1 panel inside -- strip lights at the ceiling -- and air conditioning, our area gets really hot in the Summer. These were grounded back at their source of power -- not treated as independent buildings. ( Never inspected ) Since you're not going to be held to the NEC standard -- don't sweat such a detail.

Modern LED lighting and the A/C system can really take voltage sag without much complaint, anyway.


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## SeabeeElectrician (May 14, 2020)

telsa said:


> The CBs are NOT going to be held to the NEC voltage drop specs. These are essentially temporary facilities for surge needs.
> 
> It smells like these will be used for the Wuhan virus -- as isolation quarters.
> 
> ...



They won't be featured on MTV's Cribs, that's for sure.



I don't always have the opportunity to follow the NEC to a T when I'm overseas but I always do my best effort to meet or exceed it and any other local codes I can dig up.


I'm planning on grounding the RST cages in my footers with a clamped on #8 that will connect to both 100A subs, as well as to a ground rod for each. Is that overkill?


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## CoolWill (Jan 5, 2019)

SeabeeElectrician said:


> I'm planning on grounding the RST cages in my footers with a clamped on #8 that will connect to both 100A subs, as well as to a ground rod for each. Is that overkill?


Sounds fantastic. Just be double sure to NOT ground any neutrals after the main.


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## SeabeeElectrician (May 14, 2020)

First, let me say thank you to everyone for your input. Here's the plan:


-Run my conductors to a pull box near main panel (can't really fit a gutter because of random conduits coming off everywhere)
-Inside the pull box use polaris taps/in line crimp splices (depending on availability) to step up conductor feeders for each sub to 2x 350KCM aluminum ungrounded, 1x 250KCM aluminum grounded, 1/0 copper grounding

-run feeder sets in 2x buried 4" PVC ducts
-before 100A sub panels use polaris taps/in line splices to step conductors back down before entering subs -* I'm unsure of this. Does the NEC allow you to down-size your conductors in this way? *I'd assume you can because they're still meeting required ampacity requirements and up-sizing was just for voltage drop reasons, but I can't find anything specific. The electricians I've run this plan by are also not sure.
-ground both subs to the footer RST and ground rods


With the anticipated cost of these conductors I'm going to try and see if we can just get another service point installed closer to the subs. *I am also concerned that this install may be overloading that 400A service* with everything else on there, but I have no real way to tell what the actual load is from here. This is more ammo in the "install a new service" argument.


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## Bird dog (Oct 27, 2015)

SeabeeElectrician said:


> -ground both subs to the footer RST and ground rods


IIRC Art 250 says you can't have Aluminum any closer than 18" to dirt ground. I know you said you were planning on using copper.




SeabeeElectrician said:


> With the anticipated cost of these conductors I'm going to try and see if we can just get another service point installed closer to the subs. *I am also concerned that this install may be overloading that 400A service* with everything else on there, but I have no real way to tell what the actual load is from here. This is more ammo in the "install a new service" argument.


Do a load calculation.


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