Hello everyone, I need to run a 30amp 240v line into my garden so I can run the lights on a different circuit then my AC. I will only be running 2K for now but would like to upgrade to 4K as soon as I can so I want the wire to be able to handle 4K watts not just 2k. That being said I have done some research and want to use 10/3 wire of some sort. I know I could get away with something smaller but the run is kind of far, 60ft or so, so I want to do things the right way. Now the question I have is what kind of wire I should use. I really like the 10/3 mc wire because of how safe it is against weathering and rodents. But the price is crazy! $189 for 125ft. So would it be okay to just run romex like wire instead? I will be going from the breaker box, which is located outside, up the outside wall and right into the attic. Will the romex wire be safe ran up the wall and through the attic? or willl some kind of conduit be needed? I am trying to do this as cheap as possible for now to get my garden functioning again. OH almost forgot will I need 2 phases a ground and a neutral? or just 2 phase and a neutral?
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Electrical advice needed
- Thread starter Greeco
- Start date
thegambler
Active member
I just paid $55 for 50 ft. 12/3 wire so the price is not unreasonable......... romex is not called for in your situation. Spend the money and be safe..... and I don't think any of these wires are meant to be outside the house.......
Im using SOOW 8-4 from my main to my sub in the flower room. It runs under the house. This is where I got it. Don't know if its cheaper elsewhere. This is good for 35amps. 161$ for 75' not including shipping
http://www.skycraftsurplus.com/84soowpowercord.aspx
http://www.skycraftsurplus.com/84soowpowercord.aspx
G
greenmatter
prices are crazy for everything these days. in this game wiring IS NOT THE PLACE TO TRY AND CUT CORNERS! shop around and get the best deal you can, but make sure you buy large enough wire. it costs more to do it twice
okay thanks a lot guys, I will just get the 10/3 mc wire so that I can run it in or outside and I won't have to worry about rats. Not that I have any but I don't want to deal with some rodent coming along and chewing through my wire. I agree it is better to be safe than sorry when it comes to running wires. BUT will I need two hots a neutral and ground or two hots and just a neutral? The reason I as is because I have seen 10/3 MC wire with 4 wires and some with 3.
10-3 is blk,whit,grn this is only 1 hot for 120v.......10-4 has red,blk,wht,grn this has 2 hots for 240v.....I would get the 10-4.. wire it for 240v and 120v....
junior_grower
Active member
That is 10/3 w/ground. Straight 10/3, as Hammerhead said, has only 3 conductors. I don't know if it is even still available, but you used to be able to buy romex either with or without the ground and it didn't impact the conductor numbering system, it just added or deleted the w/g at the end of the coding. 10/3 in a cord has no bare conductors, and there would be only 3 wires. For instance, if you wanted to run 120/240 with a ground in SO cord, you would want 10/4 (red, black, white, green).
ya here is a pic for reference ..This is 10-3 only 1 hot.....10-4 has 2 hot. I dont like the MC cord. Its ugly having that stuff running on the outside of your home. I like the very flexable So cord for easy installation plus you dont see any it's all under the house. The only part I see is the 4' that enters the room from the floor.. You will need to strip off around 5' of that metal so you can feed the wire into the main panel also on the other end up into the house where the sub panel is.
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What you need is 10/3 uf-b wire. It is the gray wire that has 2 conductors with a bare ground. Ground and neutral attach to the same bar in your panel. 115 volt uses 1 conductor and a neutral/ground. 240 volt is 2 conductors with ground/neutral. the uf-b wire is for direct under ground or above. It is double insulated and sun light resistant. No conduit needed. Or if you want it in conduit just use romex. Can be bought at any hardware store, home depot, lowes ect. 50' is border line for stepping up awg size to 8.
The ground and the neutral are separate wires, have entirely different purposes, and the ground should never be used as a neutral. They do land on the same buss in the main panel, but are isolated from one another in the sub-panel and any connected devices.
In electrical parlance, the neutral is the grounded conductor, and the ground wire is the grounding conductor. The grounded conductor is called that because the neutral tap is grounded at the utility transformer and at the service ground rod. As a current-carrying conductor, it is an active part of the electrical supply to the appliance.
The ground wire is not meant to be a full-time current-carrying conductor - it is only to carry the fault current in case of a failure in the insulation on the current-carrying components. It's function is to provide a low-resistance path for the fault current, assuring that the circuit protection (fuse or breaker) activates quickly.
The two are only bonded together at the main panel because multiple connection points throughout the system can create stray currents on the ground (ground loops), which will raise hell with sensitive electronics.
Everybody had enough electrical theory?
burns1n209
Member
everyone keeps mentioning 10/3, if you want to run your 4k setup you will need minimum 6/3. It is rated for 55 amps. 8/3 is 40amps, and 10/3 is 30 amp. That being said even if you could run an 8/3 you can only run at an 80% load on a 40amp breaker and with 4k light setup comes to just about 37-38 amp. You will be fully maxed out possibly tripping breakers on hot days. If you wanna do everything right and not burn down the spot, you need to run 6/3 CU from main to a 55 amp sub panel in the room. The cheapest way to do this is run 4-4-4-6 SER aluminum. similar to copper romex but it is aluminum wire, which is a shit load cheaper. you have to up the size to the next biggest for the wire, but even then aluminum 4-4-4-6 is 1.39$ compared to 2.30 for 6/3 copper.
Cheapest i could find...
heres a link for the 4-4-4-6 SER
http://platt.com/platt-electric-sup.../Multiple/43SERGX200/product.aspx?zpid=358305
Heres a link for 6/3 CU NM-B
http://platt.com/platt-electric-supply/NM-B-Type-6-AWG/Multiple/63NMBGX1000/product.aspx?zpid=69540
Cheapest i could find...
heres a link for the 4-4-4-6 SER
http://platt.com/platt-electric-sup.../Multiple/43SERGX200/product.aspx?zpid=358305
Heres a link for 6/3 CU NM-B
http://platt.com/platt-electric-supply/NM-B-Type-6-AWG/Multiple/63NMBGX1000/product.aspx?zpid=69540
burns1n209
Member
I would assume (and did) that if he was going to run 4k, he would drive his ballasts at 240v. This would result in a lighting load, aside from ballast losses, of just under 17 amps. If his a/c is on a separate circuit, he should be fine with the 5700+ watts that he would have available from an 80% loaded, 30a 240v circuit. The 80% limitation only refers to continuous loads - shorter duration loads can run up to the full rating of the breaker.
That said, if it was me, I wouldn't bother to run a sub-panel without carrying 60 amps to it.
Nice drawing! Note that the ground rod on the sub-panel is only required if the sub is in a different structure than the main.
sourpickle
New member
55 amps at 240 volts = 13,200 watts.
Op only wanted 4,000 watts in lights plus fans and shit(maybe 1,500 watts) and that's only 5,500 watts. That makes 22.9 amps. So whatever size wire runs 30 amps at 60ft will work.
Op only wanted 4,000 watts in lights plus fans and shit(maybe 1,500 watts) and that's only 5,500 watts. That makes 22.9 amps. So whatever size wire runs 30 amps at 60ft will work.
sourpickle
New member
Rives types faster. We should listen to him. Lol
what does a 1k ballast run in amps I thought it was 4a 4x4=16 amps @240v... Plus what ever else he is running.. I have 8-4 this will give me 4k no problem. Im at 3500w right now total lights,AC,Pups,fans. Im running a 50a breaker to my sub. with my 8-4 40a max...
Since we are talking about a 240 volt circuit there is no neutral. I won't argue the bonding in the panel at this time even tho I do not agree.The ground and the neutral are separate wires, have entirely different purposes, and the ground should never be used as a neutral. They do land on the same buss in the main panel, but are isolated from one another in the sub-panel and any connected devices.
In electrical parlance, the neutral is the grounded conductor, and the ground wire is the grounding conductor. The grounded conductor is called that because the neutral tap is grounded at the utility transformer and at the service ground rod. As a current-carrying conductor, it is an active part of the electrical supply to the appliance.
The ground wire is not meant to be a full-time current-carrying conductor - it is only to carry the fault current in case of a failure in the insulation on the current-carrying components. It's function is to provide a low-resistance path for the fault current, assuring that the circuit protection (fuse or breaker) activates quickly.
The two are only bonded together at the main panel because multiple connection points throughout the system can create stray currents on the ground (ground loops), which will raise hell with sensitive electronics.
Everybody had enough electrical theory?
For a straight 240v circuit, you are absolutely correct. However, I would never run anything but a 120/240 circuit for a grow room simply because of the flexibility for the future. That aside I was referring to this -
To me, this infers that the two conductors serve the same purpose, and I wanted to clarify that they do not. Burnsin209's drawing does a nice job of showing the code requirements, and I was explaining the theory behind the code.
