60amp power to hobby shed

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  #1  
Old 04-01-07, 07:09 AM
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Exclamation 60amp power to hobby shed

I am in the process of constructing a "hobby shed" on the back of my property and require 60 amps of power at that location. I have been advised to use a 60amp wire. I want to tap into the current power panel located on the interior of the house and run another line to the new location.

There is about an 80 foot run from the current inlet to where I will require a sub-power supply box. This new box will have about 8 to 10 outlets installed. How must I install this 80 ft run of cable??

Underground would be convenient. At what depth do I have to run this new wire and what sort of an approved conduit would be required?? Do I start the run inside the house at the main junction box, or must I start on the outside where the current power is coming off the telephone pole?

Seggy
 
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  #2  
Old 04-01-07, 08:43 AM
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Seggy, please do not take this the wrong way, but your use of termonology tells me that you are not very familiar with electrical work.

You should start at the book store or library finding a good book on residential electrical work. Understanding not only the "how to" but also the "concepts" is important.

You must start with a demand load calculation on your existing electrical system. We need to be sure that your service can handle the added load. This is not as easy as just adding breakers, or looking to see if the panel will hold the new breaker. If you are not sure how to do this, then learn how from the books before you add the additional load to your home.

You will be starting the run at the main panel in your home. Not knowing what you have now, I cannot tell you if that is outside under the meter, within the meter enclosure, or inside the house.

Depending on where you live, you can probably use either conduit underground, or direct burry cable. Each has its advantages and disadvantages.

You need to decide now if you will be running telephone, gas, water or any other things to the new shop, either now or in the future. This is important as it effects the number of wires you need and the proper way to ground this new part of your electrical system.

Do a demand load on the existing home, next do a demand load on the new shop. then we can figure out the rest of what you need.
 
  #3  
Old 04-01-07, 09:42 AM
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What all do you intend to put in this hobby shop? Is it just going to be some lights, some receptacles and a couple light woodworking tools? Or is this going to be some full-up workshop with welders and professional-grade 240V tablesaws, with climate control and a dust handling system, etc?

I ask this just for a reality check before we send you off in the wrong direction. Honestly, for most purposes, a 20A circuit shared between lights and receptacles will be ample for 1 cord-and-plug tool running at any given time, and will be far cheaper and easier. (FYI, I ran my workshop shed for years off an extension cord plugged into an outlet, until I got around to wiring it properly. The lights flickered from in-rush voltage drop whenever I started up the radial arm saw, but that was more because the extension cord was too small and about 100' long.)

If you are building a substantial hobby shed that requires a 60A feeder, and if you plan on doing all the work yourself, you have some learning to do! I'd recommend also buying a copy of IRC (international residential code), which includes all the relevant portions of NEC as well as the other codes for building structures.


FYI, there are various rules for burying cable- 60A cable in PVC conduit must be bured 18" deep. But the depth varies depending on conditions and how you run it.
 
  #4  
Old 04-01-07, 10:15 AM
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jwhite
Many thanks for your quick response!! You are quite correct, I am not familiar with electricial work, but do know how to "string" wire, etc.,etc.
I would just place the wiring and employ a qualified electrician to do all the hook-ups.
I shall indeed purchase a book on residential electrical work, as you suggest. I will then be able to figure out the current demand load and go from there.

Currently, the meter is like all residential homes, on the outside. The fuse box is on the inside which is where the 220 off the street comes.
I will also seek more advice from a colleague who just happens to be a retired electricial.
I will reply again when the load demand is known.
Seggy
 

Last edited by John Nelson; 04-02-07 at 11:38 AM. Reason: eliminate quoting
  #5  
Old 04-01-07, 10:34 AM
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grover..

Many thanks for your quick response!!
I have recently retired (Jan26, 2007), and plan to move my woodworking hobby out of the basement into a 15 x 36 "hobby shed". Inside this shed will be electical woodworking tools; i.e. table saw (120v), radial arm saw, band saw, lathe, ploaner, etc.,etc. I have caculated that I would not be using more that 15amps of power at any given time (plus lighting) . I have in the set-up plans about 8 power plug ins and about 6 on/off switches (for lightes, vac, fans) etc.,etc.
It will not be a full time workshop, it is a way to get myself out of the basement and outside into a separate building. It will be heated via a wood stove only.
I did think about the one extension cord with a power bar, which I will have to use first off. However, I also have a compressor, which suggests inferior compression with an extension cord.
A local vendor recommended the 60amp as a minimum and did suggest the 18" of depth inside a conduit to string the cable.
I have had two responses to my query and both suggest to puchase a book on electrical work.
I would only be involved in stringing the wiring and let a qualified electricial do the actual hook-up. I am only looking for suggestions on how to do the preliminary work so that this "hobby" shed does not cost me an arm-and-a-leg to construct.

Seggy
 

Last edited by John Nelson; 04-02-07 at 11:37 AM. Reason: eliminate quoting
  #6  
Old 04-01-07, 11:27 AM
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Originally Posted by Seggy View Post
I would just place the wiring and employ a qualified electrician to do all the hook-ups.
If you can find an electrician who will let you pull all the wires, then will come in and make the final connections, I will call him a hack and a licence seller.

this is even illegal in the state that I live in.

Either study, pull the permits and do the work yourself, or hire the entire jobs done..
 
  #7  
Old 04-01-07, 01:10 PM
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Ah, OK- you only really need a single 20A circuit going out there, which fortunately for you, GREATLY simplies thing, and were likely recommended to use 60A (#6 cable) for voltage drop. That's OK, there's nothing wrong with oversizing the cable! And it drops this job from "hire a pro" to "you can do it yourself with a bit of education and perseverence"

Are you going to be building the shed yourself, too?

You're going to need to put a new 20A breaker in your electrical panel. You'll want to use underground feeder cable (UF) for the outside run. #12-2 cable is the minimum required, but you'll see a 6V drop over an 80' run under heavy loads (dropping 120V to 114V) and even lower, likely to 108V or so when the large tools spin up. This amount of drop is legal, but there's nothing wrong with oversizing- #10-2 or #8-2 will reduce voltage drop ro 4V and 2.4V, respectively. #6 (60A cable) will reduce that to 1.5V. If I was in your shoes, I'd probably run #10-2 UF (30A cable), as it's readily available and easy to work with; the larger gagues can get to be a pain for a DIYer, and #10-2 UF is stiff enough to work with as it is!

UF can be run through your house just like Romex, and is legal for direct burial in an 18" deep trench, unless you're going under your driveway or other special conditions. (If you install a GFCI panel breaker on this circuit, you fall under a special exception and only need to bury it 12" deep.) For protection, it's a good idea to still put it in conduit- SCH40 PVC conduit is cheap and easy. Either way, you're required to encase it in conduit where it comes up into your house and your shed. Once in your shed, you need a disconnect switch- either an HVAC disconnect box, or a heavy-duty light switch. You don't need a panel, just split right off that to your lights and receptacles- use #12-2 NM-B (romex) cable in your shed.
 
  #8  
Old 04-01-07, 01:38 PM
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I do not recommend a single 120 volt circuit. While it sounds like that will work, a trip of the breaker will leave you in the dark if you are there at night.

I recommend at least a multi-wire circuit. If it were me, I would run 10-3 UF cable, protected by a 240 volt 20 amp breaker. This will give you two separate 120 volt 20 amp circuits at the shed. This would allow you to either separate the lights from the tools, or have two circuits which you put a light or two apiece on and then use for receptacles, allow two of those tools to be run at the same time.

Another alternative would be to bury conduit, which would allow you to change the wires at any time to increase the circuit size.
 
  #9  
Old 04-01-07, 07:24 PM
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Your original post asked about burial depth requirements. There are different requirements for different situations, so let's defer that answer until the other details are settled.

The key to happiness in this project is an accurate prediction of the amount of power you will need (expressed in watts). Once you come up with that number, the rest of the details will fall rapidly into place.
 
  #10  
Old 04-02-07, 07:12 AM
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Grover.
Wow!! Many thanks for your below reply!! Your alternative to a 60amp to a 30 amp installation cable sounds like the way I will go. As you say, this # 10-2 UF cable will certainly be easier to manipulate around 90 degree angles, etc.,etc.
I plan on building the "hobby" shed on my own. Since I have recently retired, I have all summer to finish and do a "proper" job.
I will encase this #10-2 in a conduit at a depth of 18" for the 75 ft run.
I will have a qualified electrician install a 30 amp breaker at the main switch located inside the house and commence the run from there to the shed.
Great advice!! Meaning that I now do not have to purchase a 60A sub-breaker for the inside of the shed. A dis-connect switch inside the shed is the way I will go.
Yes, # 12-2 romex will be inside the shed to all other outlets.

Steve
 

Last edited by John Nelson; 04-02-07 at 11:37 AM. Reason: eliminate quoting
  #11  
Old 04-02-07, 07:16 AM
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Steve,

You cannot connect wires protected by a 30 amp breaker directly to your lights and receptacles, no matter what the wire gauge.

If you want anything except a 20 amp circuit or a 20 amp multi-wire circuit to the building, then you need a sub panel and the appropriate ground rods, etc at the building.
 
  #12  
Old 04-02-07, 07:19 AM
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John.
Not sure if you get to read all the threads on my original query, but grover has given me the best suggestions as of yet. As I will only require a maximum of 30A within the "hobby" shed at any given time, I will run a #10-2 wire from the "box" in the house, underground in a proper conduit at a depth of 18", with conduit in the house, as well as to the connection box within the shed. Then #14-2 romex for the interior. There will be a slight voltage loss, as the run is about 75ft, but according to grover, well within the limits allowable.
Do you have any comments on the above details??
Seggy.
 

Last edited by John Nelson; 04-02-07 at 11:36 AM. Reason: eliminate quoting
  #13  
Old 04-02-07, 07:26 AM
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racraft...
Not sure if you get to read all the other threads connected to my original query?? What do you think of the suggestion by grover? To myself, who does not totally understand electricity, but have enough knowledge to know that wire size does matter and that over a greater distance, there will be a voltage drop. Plus #14-2 romex seems to be the standard for what I require for inside the shed.
Separating the lights from the tools, is also an excellent suggestion!! The # 10-3 UF cable in a conduit is also a great suggestion.
Many thanks!!
Seggy
 

Last edited by John Nelson; 04-02-07 at 11:36 AM. Reason: eliminate quoting
  #14  
Old 04-02-07, 07:40 AM
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Stave,

I have read all the threads.

My advice has not changed.

Decide how much power you need first.

Then. run an appropriate circuit in conduit, so that you can change it later.

If you need a single circuit, go with a 120 volt 20 amp breaker using 10-2 wire or individual 10 gage conductors in conduit.

If you need the equivalent of two circuits, go with a multi-wire circuit using a 240 volt 20 amp breaker using 10-3 wire or individual 10 gage conductors in conduit.

If you need more power than 20 * 240 = 4800 watts, or if you need 240 volts at the shed, then you need a sub panel at the shed.

Unless you put a sub panel in the shed, then ALL the wires in the shed must be sized based on the breaker ion the main panel. A 20 amp breaker in the main panel will force no smaller than 12 gage wire on the circuit.
 
  #15  
Old 04-02-07, 08:02 AM
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racraft..

Many, many thanks for sharing your sound advice!!! From what you have presented to me, I now have a much better picture of what to purchase and how to install and let the professionals do the connecting.

Steve
 

Last edited by John Nelson; 04-02-07 at 11:35 AM. Reason: eliminate quoting
  #16  
Old 04-02-07, 11:41 AM
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Seggy,

You misread grover's suggestion. His solution does not give you 30 amps, but only 20 amps. So the key question is whether or not 2400 watts of power is sufficient, both now and in the future.

Furthermore, you also misread grover's wire size suggestion. He suggested to use 12/2 in the shed, not 14/2. You made two posts, only seven minutes apart, stating two different wire sizes that you planned to use within the shed. My head is starting to spin.

As has already been pointed out several times, but I want to reinforce, you need to use a 20-amp breaker, not a 30-amp breaker. And if you use 14/2 in the shed, you can only use a 15-amp breaker (and thus only have 1800 watts of power available).

Be sure to read carefully and not modify part of the advice given without understanding that it may invalidate the rest of the advice.

Also be aware that grover's suggestions and racraft's suggestions are two separate approaches. You have to take all of one or all of the other, not bits and pieces of each. If you use racraft's multiwire approach, realize that you have not been yet given all the information you need to do this safely.

This all boils down again to the need for an accurate prediction of the amount of power needed.
 
  #17  
Old 04-02-07, 05:30 PM
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Steve, a couple clarifications:

1) standard receptacles can ONLY be fed from 20A or 15A breakers. You cannot directly feed a receptacle from a 30A or larger breaker. I only said "30A cable" because that's how you were referring to it and I was trying not to overwhelm you with jargon- what I really meant was "#10 AWG Copper wire"

2) #12 is the smallest conductor size you can legally use on a 20A circuit, regardless of where it is in the circuit. So, if you use a 20A breaker, you can't use #14 anywhere, it has to be #12- you can use #10 or larger for the long haul and switch to #12 if you'd like, but you still can't use #14.

3) I actually like racraft's suggestion of using a #10-3 multiwire circuit. Multiwire circuits cancel out the neutral current and can significantly reduce voltage drop. You have to be VERY careful though, as multiwire circuit require special techniques to be safe... But there are certain advantages if you do it this way.

4) is the entire cable length 80' or just the underground portion? If that's just the underground portion and the actual length is 160'... well, you can double all the voltage drops I calculated!


If you plan to use only 1 tool at a time (maximum power: 1600W) plus lights (Maybe 300W), then a single 20A breaker is sufficient. If you plan to use, say, an air conditioner, or a dust collection system with a rating measured in fractional horsepower the same time you're running your tolls- then a single 20A breaker might not be enough. I think running #10-2 from a 20A breaker, and wiring up inside your shed with #12 will serve you well and be within your abilities

Don't forget to pull a permit and get inspected- the inspectors might make you rip it all out and redo it all a couple times, but they're just trying to keep you from killing yourself!
 
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