Shed electric site planning

[MerlinsBeard]

I'm trying to figure out what to do for routing electric to shed. For feeder, I know I want a minimum of 60A but could go higher. There's a couple of options.

I'm planning 2 PVC conduits, 1 1/2" for coax/cat6, another 1 1/2" for electric. If you check the diagram (work in progress), you can see the relative house and shed panel placements (uploading seems to compress the image size, so it's a little tiny). Basement is unfinished, but there are plans to finish it in the future.

One option is to have conduit on the north side of the house, which minimizes feeder exposure to future construction but has a longer trench route. The other is to go through ceiling joists to the south end of the house and have a shorter trench. For the cat6/coax I don't think the route matters, but for electric it could.

What are the pros and cons? Any recommendations on whether conduit is needed inside the basement section for the feeder wire till it hits the junction box/LB.

 

[mike93lx]

Conduit is needed for certain types of wire. If you run SER (4 conductors in a jacket), it is treated just like romex, so if you can keep it protected from damage, it doesn't require conduit. If you are going to run something like THWN, Xhhw or MHF, you will have to run conduit end to end.

If you run in the house, I would run SER up to the outside wall, then transition to conduit for outside with MHF. 2-2-2-4 is a very common size, which can allow you a 90a feed

Soil is extremely Rocky where I am, so I would prioritize a shorter trench. Also keeps the wire out of the way from work in the yard

1.5" is also way bigger than needed for a coax and a cat5

 

[nadogail]

IMHO, you should allow room for growth in your electrical planning. What was standard in years past is no longer considered adequate.

For example when I was in high school a 100 Amp residential service was considered very big, now it is the minimum size allowed. 200 is often used for garage workshops.

 

[wyliesdiesels]

Conduit is needed for certain types of wire. If you run SER (4 conductors in a jacket), it is treated just like romex, so if you can keep it protected from damage, it doesn't require conduit. If you are going to run something like THWN, Xhhw or MHF, you will have to run conduit end to end.

If you run in the house, I would run SER up to the outside wall, then transition to conduit for outside with MHF. 2-2-2-4 is a very common size, which can allow you a 90a feed

Soil is extremely Rocky where I am, so I would prioritize a shorter trench. Also keeps the wire out of the way from work in the yard

1.5" is also way bigger than needed for a coax and a cat5

To add to this, SER is not permitted for use underground

 

[MerlinsBeard]

In my area, the soil is not rocky, so I don't anticipate an issue with the trench work. My initial thought was to do XHHW 2-2-4-6 from panel to panel (conduit in the basement). The joists in the basement run east to west, so if I conduit through the joists to get to the southwest corner, there's some ductwork that makes things a little tricky. If I avoid that and travel down the existing joist west from the house panel, I have a longer trench.

Haven't considered SER to XHHW though, certainly seems like it could simplify installation effort since it avoids conduit if I route inside the house to the southwest corner. How does the transition happen? Any issues over time when you have that kind of connection.

 

[mike93lx]

IMHO, you should allow room for growth in your electrical planning. What was standard in years past is no longer considered adequate.

For example when I was in high school a 100 Amp residential service was considered very big, now it is the minimum size allowed. 200 is often used for garage workshops.

200a for a garage workshop is way overkill. My entire house doesn't even have 200a and I am nowhere near that being a problem.

The average user would be very unlikely to ever need more than 60a. A business with multiple people? Sure.

 

[mike93lx]

In my area, the soil is not rocky, so I don't anticipate an issue with the trench work. My initial thought was to do XHHW 2-2-4-6 from panel to panel (conduit in the basement). The joists in the basement run east to west, so if I conduit through the joists to get to the southwest corner, there's some ductwork that makes things a little tricky. If I avoid that and travel down the existing joist west from the house panel, I have a longer trench.

Haven't considered SER to XHHW though, certainly seems like it could simplify installation effort since it avoids conduit if I route inside the house to the southwest corner. How does the transition happen? Any issues over time when you have that kind of connection.

It is just a splice, in a box. Box size is dictated by the size if the conduit entering it (it is some multiplier that I can't remember. Polaris connectors are nice, but expensive. Split bolts are cheap, but require a bunch of specific tape

 

[alfredeneuman]

If you are going to run something like THWN, Xhhw or MHF, you will have to run conduit end to end.

MHF only needs conduit inside the structure and outside to prevent physical damage. not underground

 

[mike93lx]

MHF only needs conduit inside the structure and outside to prevent physical damage. not underground

Good point I actually mentioned mhf being direct burial later in my post. Should have made that clear here as well

 

[theoldwizard1]

In my area, the soil is not rocky, so I don't anticipate an issue with the trench work. My initial thought was to do XHHW 2-2-4-6 from panel to panel (conduit in the basement).

that sounds like MHF (mobile home feeder). It can be direct buried, but it must be in conduit inside of a building. If you buy it as MHF it is a bit cheaper.