Trenching line from off grid power shed to house -- what to include?

[PorkChopsMmm]

Thanks NM. This wire looks excellent -- never knew it existed. I might hold off on it for the time being and string it through when needed. I am trying to keep the trenching project under $500 and with wire costing ~$350, conduit costing $70 (or more, depending on what I enclose in conduit, and the CAT6 and coax costing another $70 combined I am starting to cut it close. I still need to rent the trencher.

[PorkChopsMmm]

OK, everything is set to go for this Friday. Trencher reserved, some wiring shipping via Amazon, picking some up locally on Thursday.

Here is what is going in the 250' trench (in no particular order...):
- 2-2-2-4 aluminum feeder cable (direct buried)
- 1" 80 PSI poly pipe for a water spigot
- 1 1/2" conduit for low voltage wiring
- 2 CAT6 ethernet runs (1 for the Outback MATE inverter controller and 1 for a security camera, computer, etc.) in the conduit
- RG6 coax in the conduit
- Poly fish line for pulling in future wires in the conduit (linked here:http://www.amazon.com/gp/product/B001UKL6BG/ref=oh_details_o02_s01_i00)
- Detectable 'caution' tape buried at the top of the trench (linked here: http://www.amazon.com/gp/product/B0081ZRVAI/ref=oh_details_o02_s00_i01)

Questions:
- Do you think 1 1/2" conduit is big enough for 1 coax and 2 CAT6 runs? I am trying to plan ahead about pulling max 1 more wire in the future and not sure if it would work without binding
wire.
- I plan to run schedule 40 conduit underground and then run schedule 80 above ground. since the conduit is 1 1/2" and I still need to enclose the direct buried feeder cable I was going to surround it with 2" schedule 80 coming out of the ground. Sound like a good plan?
- What order would you place the wiring in the trench? I plan to go down 36". So first water line, then 6" of dirt, then 2-2-2-4, then 6" of dirt, then 1 1/2" conduit then more dirt and finally the detectable tape and covering up?

Don, I plan on running the wires in conduit the same way you did -- laying the wires out on the ground and then sliding conduit over the wires.

[PorkChopsMmm]

Here are some pictures. It took much longer than expected and I still need to clean up some some wiring with conduit in the barn. It didn't help that it rained all second day. Trenching, digging, and working with electricity in the rain and wet is not fun.

[OlJarhead]

http://www.midwestamericom.com/whitepapers/cabling/Conduit%20Fill%20Capacity%20Table.pdf
Yes to your question about the cat6 and coax.  The table above will show you just how much can be fished through but here's a question or two:  why cat6?  why two?

Just curious but 250 feet is inside the 10BaseT limit of 100 yards and 10Mbps is usually more then enough for most Ethernet applications (so cat5e would be fine -- actually it's good to 1000BaseT or Gigabit Ethernet).  Also, if you're using Ethernet then why not install a switch and run one cat5e cable down the pipe leaving plenty of room for other cables in the future.  Then you connect each item needing Ethernet back to the house to the switch and use a simple router to manage IP addresses (private of course).

Specially if the idea is to be able to monitor the systems with a laptop or PC -- because then you connect it to the Router and have all the access you need to all systems (and more later down the road) all on one cable?

Might be late to bring this up (sorry) but it's sorta what I do

[OlJarhead]

On a side note, I'd have run the Direct Bury stuff in the pipe too -- why not?  After all, the PVC keeps the rodents away

[PorkChopsMmm]

http://www.midwestamericom.com/whitepapers/cabling/Conduit%20Fill%20Capacity%20Table.pdf
Yes to your question about the cat6 and coax.  The table above will show you just how much can be fished through but here's a question or two:  why cat6?  why two?

Good question! My solar components are made by Outback Power and it uses an LCD screen to interact with the inverter, charge controller, battery monitor, etc. It uses RJ45 for connectivity to these components but *does not* use TCP/IP protocol -- it is using the RJ45 but basically using it for serial communications. Because of this it does not work to connect the RJ45 from the MATE to a switch -- the MATE and the other components must be directly linked by the RJ45. Because I wanted to have a switch out there in the future for a computer, security cameras, etc. I ran the second RJ45.



CAT6 and CAT5e are almost the same price but ground rated CAT6 and coax are much higher in cost than non ground rated. Ideally I would have gone with ground rated with everything but I cut cost there.

[OlJarhead]

RS232 or something similar then -- but it makes sense either way.  Good explanation too!

And it looks like you've got it covered well.  Good luck!

[firefox]

Just a bit of info here.
Although the specs for RS232 specify a ridiculous short distance, in
most cases it can go quite a long distance. I worked as a Tech at UCBerkeley and we
had connections go from the fourth floor of one building and then about two
buildings away  to a fourth floor of another building.

What realy surprised me, was they were using 2 wire telephone twisted pair and
then using the power ground on the terminal for the return. We were able to use this at 9600 baud rate.

The down side to this was that during an electrical storm the ground potential
difference between the two buildings would spike and blow out the uarts in the
terminals.

Obviously you needed to do some jumpering on the connectors to make this work
but it did work and worked well for about 10 or 15 years before we switched to ethernet.

So for the practical point to this info. If you are trying to use an RS232 link for
control purposes and you want to minimize conduit use, I would recomend
getting some rugedized telephone drop cable. The kind that is used to go from your house to the pole. I believe it has 3 pair in it, but if it only has 1 pair and you have a ground wire in your conduit, you should be good. This stuff is indestructible and even if the conduit is flooded, you wont have any problems.

Bruce

[PorkChopsMmm]

Sorry I wasn't clear on this guys. Outback equipment only has RJ45 jacks for connecting equipment. It happens to only use a few wires out of the RJ45 cable. It can go very far distances -- much further than normal CAT5E or CAT6 distances. There are no RJ45 to RS232 splices here or anything.

[firefox]

Here is an expensive way to doing this type of operation, but ther is no issue about
having both power and communication in the same conduit.

Just use FiberOptic cable for the com link. It is not cheap, but not prohibitive,
and if it cuts down on trenching and conduit efforts through rough terrain, it may be
worth it.

All you need is a fiber optic hub to attach to each end to convert it to 100BaseT
ports. There are converters to use that convert ethernet to RS232 which you would have to get for each end.

Like I said, it does cost more, but in certain circumstances it may be the only
thing that will work without breaking the budget.

Bruce

[firefox]

In reference to the following " There are no RJ45 to RS232 splices here or anything."

RJ45 is just a type of connector and is not related to the signal protocol used on the cable. RS232 is a signal protocol and was originaly used with a 25 pin connector
and cable to go with it.

Without examining the specs used with that particular device, I can't promise anything, but I suspect that it is just a matter of connecting the right wires together
and you are good to go.

I am not recomending this unless you are familiar with this sort of thing, or have
a friend that knows about the various communication protocols.

This is only intended for information only for people in a bind that may give
them a clue for a solution.

Bruce

[OlJarhead]

Sorry I wasn't clear on this guys. Outback equipment only has RJ45 jacks for connecting equipment. It happens to only use a few wires out of the RJ45 cable. It can go very far distances -- much further than normal CAT5E or CAT6 distances. There are no RJ45 to RS232 splices here or anything.

'Craft' often called 'RS232' ports can be serial (9pin) or RJ45 -- I think maybe even 25pin but why would you do that?  Anyway, so the RJ45 connector can actually be for a craft port or RS232 port.

http://en.wikipedia.org/wiki/RS-232

[JRR]

I think, but do not KNOW ... that "direct burial" cable is designed just for that, direct burial.  I believe that I have read that direct burial, as opposed to being in a conduit, allows the cable more readily to dissipate heat into the earth.  Years ago when I was a working lad, I would have been able to back this point up with some reference manufacturers' data ... but these days, its all stuff "I think I recall".  Very shaky info!

[considerations]

power in the power shed

This idea depends on how the AC out works on your inverter, but you may be able to do a second AC out from the inverter to a  single 15 amp house type breaker (there are little breaker boxes for this) in your shed - then on to an AC switch outlet combo - and on to a light fixture. Gives you some power/light options in the shed...materials not much $'s.

Conduit run

Considering its length...if you can manage it, have you considering running a spare set of main AC out to the house...easier than pulling replacements after the conduit is installed. 

Also, electricians use some kind of goop to make the wires move more easily during the pull..

[PorkChopsMmm]

It's not in the pictures, because honestly it is too messy and I need to clean up the conduit, but I have the AC OUT from the inverter going to a breaker box. In the breaker box I have the large 2-2-2-4 going to a 60 AMP breaker, which feeds the house. I plan to wire the rest of the barn and just add in more breakers to the box.

I didn't use pulling gel for running the AC wires or the low voltage stuff but I have used it to get the 2-2-2-4 through some conduit. I am really struggling with that wire and 2 90 degree turns in 1 1/2" conduit. I think I am doing to junk everything I have done and move to 2" conduit.

[firefox]

If this has to be to code, then check the manual for size of conduit required and number of turns etc. permited. Conduit is cheap compared to the effort of trenching etc.
Good Luck,
Bruce

[considerations]

"2 90 degree turns in 1 1/2" conduit"

I don't know about conduit size codes, but I did learn that sometimes 2 of those long sweeping 45 degree bent conduits make a 90 degree direction change easier to pull.

[mfsangel]

Hi,

I would recommend considering voltage drop for you 120V power. A basic rule of thumb is to up size your wire by one size for every 200' or so.

So I would recommend either #10 THHN or #8 depending on your loads etc at the other end. Probably #8 to be on the safe side to a disconnect panel at your house. A fused puller would be fine for that or a small 2/4 electrical panel and then distribution from there. I am not sure what you are looking at for amperage output from your panels/inverter system either?

Regarding the CAT5/6 IMHO the CAT6 is possibly wasted money unless it is specified by the manufacturer. Typical trench separation is 12" so if you have a 12-16" wide trench you can lay the CAT5 conduit next to the power wiring. Mainly this is to prevent interference etc. I would probably dig slightly deeper than your frost line say 40" and then backfill the conduits slightly and add another spare conduit above it in something around 1" PVC. 2" PVC seems like overkill. It is also recommended to add a concrete handhole somewhere in between. You can take two concrete handholes or more and stack them with the first upside down and the next right side up. Backfill underneath it with pea gravel for drainage and install either prefab 45" stubs to either end for ease of connections.

The handholes can be set to grade and probably should be around 24"x12 or 16" wide depending on what is available. You can use a propane torch, gas stove or gas grill to heat the PVC for bending but the PVC is really inexpensive. Glue everything outside of your trench and then drop it in. If you have obstructions like roots or pipes you can tape it up and slide it through the trench in a long section etc.

Good luck with this project.

Roger

[mfsangel]

Hello again,

Sorry to be the naysayer of doom here but the cable you have in your picture on the spool looks like triplex type cable. If you direct bury it the aluminum will eventually decay. It is made for overhead spans for power poles typically.

The stuff you want is called UF cable. It typically is gray and can be direct buried over sand or soft backfill. I personally hate the stuff since it tends to go bad or can get cut etc. I would recommend using conduit with THHN type wiring. It is really important to know how far the run is. Typically rolls of wire are 500'. Code requires a pull box at 200' or so. I have had wiring that got abraded while pulling super long runs (500' or so) and every conduit on the planet will eventually fill with water. The water will get to the wiring and short it out. Also, most fish tapes are around 225' max. You can use jet line instead. A bucket of line (1000') runs about $50.00 bucks or so, maybe less. You take a shop vac and put it on one side and tie the jet line around a plastic baggie like a grocery bag or ziplock bag. You want to create a slight seal so the back slips easily into the conduit and the jet line does not have any edges to hang up. One person can create a seal with the shop vac. We typically will wrap a rag or duct tape to create a good seal and then fire it up. You should expect to have your jet line in the conduit in about 10 seconds or so.

The jetline will work perfectly for the wire pull. Just strip back the insulation on the wire and cut about half of the strands off (Use stranded THHN since it is either #8 or #10) it is significantly easier to pull than solid wire. I would recommend 1" PVC for the power feeder. It is easier to heat and bend than 1 1/4" and will be more than adequate. I don't have my wire chart with me but 1" is good for #6 THHN with two hots, a neutral and a ground wire so the #8  will fly through the pipe. I typically use a piece of 1/2" EMT for the wire spools set between two ladders or other suitable wire support. In any case if you have any other questions please ask.

Cheers,

Roger