M4wd&Fabrications

Projects place => Projects Section => Topic started by: cracker on September 29, 2020, 11:47:30 AM

Title: Electric planning
Post by: cracker on September 29, 2020, 11:47:30 AM
So I need to add some additional outlets at the barn, need some help figuring out correct wire and breakers to use:

1.) Outdoor outlets about 250' from panel. Possibly running 2 water tank heaters(about 1500 watts each).  Would like to possibly run the first 150 indoors from the panel to the opposite end of the barn and then burying the wire out to the pasture.  The first 100' outdoor leg, will probably not be in a conduit as it will be buried deep with water line, but rest will be shallower.

2.) 30amp RV 100' from panel box. 

Title: Re: Electric planning
Post by: mr.mindless on September 29, 2020, 12:07:24 PM
my immediate inclination is that your red/orange run should be (3) 20a circuits (so you can have something besides the heater if needed). simple distance/current calculator will probably come out with 10ga wire, but I didn't check that.

the green run will be a 30a 240 and a 15/20a - same as I didn't steal a leg off a 240 run for a convenience outlet.

right breaker depends on your electrical box. Eric will probably have an opinion on doing GFCI at the breaker vs the service point, and I'm curious about that.
Title: Re: Electric planning
Post by: cracker on September 29, 2020, 12:29:20 PM
98% of the pasture plugs usage will be winter heaters, can't really think of much more we would need out there, besides possibly a simple light. 

30amp RV plug is 120v
Title: Re: Electric planning
Post by: M4wdFab on September 29, 2020, 12:35:10 PM
20 amp yes, should be 12 gage


those lines are long lol 
Title: Re: Electric planning
Post by: Wingman on September 29, 2020, 12:50:00 PM
Conduit is cheap
Title: Re: Electric planning
Post by: mr.mindless on September 29, 2020, 01:25:50 PM
shockingly cheap. 20¢/ft for 1/2" at Depot.
Title: Re: Electric planning
Post by: etk300ex on September 29, 2020, 01:26:37 PM
I agree with all Mike said.  You can only load a circuit to 80% per code.  15A= 1440W, 20A= 1920W.  Don't steal ;D.

GFCI breaker vs outlet doesn't matter. The breakers are pretty pricey though. 
Title: Re: Electric planning
Post by: etk300ex on September 29, 2020, 01:34:35 PM
30amp RV plug is 120v

Really 3-prong?  Idk anything about RVs, but over 20A @ 120V is pretty oddball.   
Title: Re: Electric planning
Post by: cracker on September 29, 2020, 01:46:33 PM
30amp RV plug is 120v

Really 3-prong?  Idk anything about RVs, but over 20A @ 120V is pretty oddball.   
from Google: http://www.myrv.us/electric/Pg/30amp_Service.htm#:~:text=The%20TT%E2%80%9330%20is%20a,is%20a%20120%2Dvolt%20device.
The TT–30 is a 30A, 120-volt recreational vehicle standard sometime it is called simply RV 30. Frequently it is confused for a NEMA 10–30 (see below) with disastrous results. Due to the appearance of the TT-30 plug, many people assume that it is to be wired for 240-volt, but this is a 120-volt device.
Title: Re: Electric planning
Post by: cracker on September 29, 2020, 01:51:55 PM
I agree with all Mike said.  You can only load a circuit to 80% per code.  15A= 1440W, 20A= 1920W.  Don't steal ;D.

so you mean a few years ago when I had 2 1500w heaters running off a single heavy extension cord, from a 15A plug I was lucky I did not burn down my barn?
Title: Re: Electric planning
Post by: TrailTamer on September 29, 2020, 01:55:33 PM
Volts is important.

you have your water heaters yet? are they 120 or 240v?

I'd at least run 240v as much as I can and put subpanel in the second pasture, then run the 120v back to the first pasture.

1500w + 1500w + 200w = 3200w

3200w at 120v is about 26.7a at 280' will need to be about 2gage ($$$!!!). 3200w at 240v run at half of amp, at about 13.3a and only need 4ga, maybe 6ga, to save money on wire. Wire size is determined by amp and distance to maintian acceptable voltage drop.

higher volt require less amp for the same amount of work, so might want to run 240v out there to a subpanel in the pasture then run 120v to your heaters (or run 240v heaters, even).

but i am no VAC expert, though. my $0.02
Title: Re: Electric planning
Post by: M4wdFab on September 29, 2020, 02:14:25 PM
o man

here we go
Title: Re: Electric planning
Post by: cracker on September 29, 2020, 02:24:31 PM
heaters are only 120v.

https://www.tractorsupply.com/tsc/product/farm-innovators-drainplug-deicer-for-rubbermaid-stock-tanks
Title: Re: Electric planning
Post by: cracker on September 29, 2020, 02:58:31 PM
if it is in conduit does it still need to be UF or can it be standard Romex?

for the 2 maybe 3 10/2 wires out to the pasture.. what size conduit?
Title: Re: Electric planning
Post by: etk300ex on September 29, 2020, 03:12:17 PM
I agree with all Mike said.  You can only load a circuit to 80% per code.  15A= 1440W, 20A= 1920W.  Don't steal ;D.

so you mean a few years ago when I had 2 1500w heaters running off a single heavy extension cord, from a 15A plug I was lucky I did not burn down my barn?

Haha that means they either never ran at the same time or weren't really 1500w.
Title: Re: Electric planning
Post by: etk300ex on September 29, 2020, 03:17:51 PM
They're just heaters, nominal voltage doesn't matter that much.  I'd run a 20A circuit with #10 to each heater.  Gives you about 5% voltage drop.  It'll be fine. 

https://www.southwire.com/calculator-vdrop
Title: Re: Electric planning
Post by: etk300ex on September 29, 2020, 03:58:31 PM
Actually, I put in 230'.  Over 250' is pushing it.  Don't forget to add vertical distance also.  Keep it under 5.5%.  I'm sure the heater won't care but it will cut down on the efficiency. 

Wouldn't be a bad idea to put a little sub panel out there as Brett said.  Run a 40A/2P 240V #8s to a little 4 space panel , then you could branch off with 20A, #12 120V circuits no problem.  Its probably a wash in cost, those little panels are $30 (well they were last I knew).   
Title: Re: Electric planning
Post by: cracker on September 29, 2020, 04:49:24 PM
ok, I did account for vertical
Title: Re: Electric planning
Post by: Wingman on September 29, 2020, 04:51:38 PM
if it is in conduit does it still need to be UF or can it be standard Romex?

Not suppose to run sheathed wire in conduit. THHN is what you'll need.
Title: Re: Electric planning
Post by: cracker on September 30, 2020, 07:47:49 AM
if it is in conduit does it still need to be UF or can it be standard Romex?

Not suppose to run sheathed wire in conduit. THHN is what you'll need.

so I need to run 6 individual wires through the conduit.. screw that.. UF direct bury it is.
Title: Re: Electric planning
Post by: M4wdFab on September 30, 2020, 08:17:09 AM
pulling wire is fun and easy lol 

im on my 9th 500' spool thoughout my barn lol
Title: Re: Electric planning
Post by: Wingman on September 30, 2020, 09:15:49 AM


if it is in conduit does it still need to be UF or can it be standard Romex?

Not suppose to run sheathed wire in conduit. THHN is what you'll need.

so I need to run 6 individual wires through the conduit.. screw that.. UF direct bury it is.

pulling wire is fun and easy lol 

It's true! You pull them in together and they slide through WAY easier than solid romex or UF ever would.
Title: Re: Electric planning
Post by: cracker on September 30, 2020, 09:34:55 AM
so basically
1.) I run standard Romex from the panel through the rafters(bundled with the rest of the Romex for the barn) down to where I exit the barn,
2.) A junction box where it switches to THHN down through the conduit and out to the pasture
3.) Does THHN continue all the way up the poles at the end to the outlet or does it switch to Romex at some point?
Title: Re: Electric planning
Post by: mr.mindless on September 30, 2020, 10:08:17 AM
Hook the conduit right to the panel. THHN all the way.
Title: Re: Electric planning
Post by: cracker on September 30, 2020, 10:14:53 AM
I really don't want to run that extra 150' of conduit and/or dig the trench that much further
Title: Re: Electric planning
Post by: Ryan on September 30, 2020, 11:19:31 AM
I really don't want to run that extra 150' of conduit and/or dig the trench that much further

Have you checked the price difference? It might be a lot cheaper to do it all THHN and conduit
Title: Re: Electric planning
Post by: cracker on October 01, 2020, 08:31:53 AM
I really don't want to run that extra 150' of conduit and/or dig the trench that much further

Have you checked the price difference? It might be a lot cheaper to do it all THHN and conduit

quick calc says THHN & full 3/4" conduit will only be about $70 cheaper.. but I say not having to run that much conduit and pulling wire would be worth the extra $70
Title: Re: Electric planning
Post by: M4wdFab on October 01, 2020, 08:49:29 AM
1/2" wouldn't work?  much cheaper. 


i like conduit just looks much cleaner and more commercial.  my barn all steel, so no where to staple to though either.