100 amp sub panel Help

[Gone_fishing]

Putting together a list of everything I will need to put a 100 amp sub panel in our shop. Hoping someone can look it over and see what I’m missing and confirm I am getting the right stuff.

200 feet 2/0-2/0-1-4 aluminum MHF wire. Distance from main panel on house exterior to outside wall on shop (where panel where be mounted just inside) is 185 feet. Is this plenty of extra?

90 amp Eaton breaker for main panel at house

Approximately 5 feet of 1 1/2 conduit where wire exits ground and enters box. 10 feet total.

2 x 1 1/2 LB’s for connection to boxes.

Square D Homeline 100 Amp 24-Space 48-Circuit Indoor Main Breaker Plug-On Neutral Load Center with Cover(HOM2448M100PCVP)

What am I missing and does this sound right so far?

Thanks!

 

[Innovate1]

Why the 90A breaker at the house? Everything else is good for 100 and 100A breaker is much easier to get.

 

[Gone_fishing]

Why the 90A breaker at the house? Everything else is good for 100 and 100A breaker is much easier to get.

Copy that. Not really sure been researching on and off for a good month or so and had 90amp written in my notes. Appreciate the heads up!

 

[Innovate1]

Many use #2 aluminum for 90A feed as it's not rated for 100A but for that length of run it's a bit light for that current and calculated voltage drop is more than it should be. 2/0 at 100A should be fine as it's oversize for 100A.

 

[u2slow]

Make sure your 100A breaker or panel lugs are rated to take #2/0.

 

[Zeke]

2 ground rods and one continuous length of armored copper wire + the correct clamps.

 

[wyliesdiesels]

1 1/2” conduit not gonna be fun to pull through. Id get 2” at least

 

[Gone_fishing]

2 ground rods and one continuous length of armored copper wire + the correct clamps.

To go from the 100 amp sub to a ground rod? What gauge wire and why two ground rods?

 

[Gone_fishing]

1 1/2” conduit not gonna be fun to pull through. Id get 2” at least

Please correct me if I'm wrong but won't I basically be slipping the conduit over the wire at each end of the run and just pulling the last few feet through the LB into the box?

 

[theoldwizard1]

Why do you think you will need 90A ? Running more than 1 welder at a time along with A/C ? Plasma cutter, 10 HP compressor, welder and electric resistance heat ?

You will save a lot of $$$ by dropping down to 60A. Then you could use 2-2-4-6 MHF.

 

[Gone_fishing]

Why do you think you will need 90A ? Running more than 1 welder at a time along with A/C ? Plasma cutter, 10 HP compressor, welder and electric resistance heat ?

You will save a lot of $$$ by dropping down to 60A. Then you could use 2-2-4-6 MHF.

Honestly I don't know that I would use 100amp. I was trying to cover for anything that was added in the future. It is a 40x60 shop and eventually 1/4 to a half of it could be living area with bath, kitchen, workout area and maybe a hot tub. The shop area is a typical wood working setup and along with some vehicle and tractor maintenance. I don't foresee more than one welder ever being used at the same time. But wood working equipment will be. I also want room for potentially adding a mini split or two in later and of coarse hot water. Yeah I don't know but figured I would be covered no matter what with 100 amps.

 

[sparky 1971]

Please correct me if I'm wrong but won't I basically be slipping the conduit over the wire at each end of the run and just pulling the last few feet through the LB into the box?

Getting through a 1-1/2" LB with 2/0 MHF is gonna kick your ****. Spend another $10-$20 and get 2".

 

[mike93lx]

To go from the 100 amp sub to a ground rod? What gauge wire and why two ground rods?

Yes. Because two ground rods are required. #6 wire

 

[theoldwizard1]

I don't foresee more than one welder ever being used at the same time. But wood working equipment will be.

Good wood working equipment typically runs on 240V (or can be switched from 120V to 240V). Twice the voltage 1/2 the current.

 

[theoldwizard1]

Getting through a 1-1/2" LB with 2/0 MHF is gonna kick your ****. Spend another $10-$20 and get 2".

Or drop down to 60A feed and 2-2-2-4 MHF.

 

[sparky 1971]

Or drop down to 60A feed and 2-2-2-4 MHF.

Or stick with the 100 amps that he wants, but use 2" conduit. I don't see how the point in trying to change peoples minds unless it's a dumb idea. There's nothing wrong with 100 amps to a garage, that's what I have, but I may or may not have put that breaker on a 2-2-4-6 MHF be cause the 60 that was there originally tripped.

 

[mike93lx]

One thing on the conduit...you have to glue it all up before inserting the wire. The glue will eat the insulation and it's a code violation to glue up after, as well.

I agree, just do 2". Screwing around with tight conduit pulls, even short ones, *****.

And get the bigger wire if you are good with the cost.

 

[wyliesdiesels]

To go from the 100 amp sub to a ground rod? What gauge wire and why two ground rods?

solid #6 cu can be ran freely without protection as long as its not subject to damage

2 rods are required by code unless you can prove 25ohms to earth. you probably dont have the equipment to do so, so 2 rods is cheaper and easier

Please correct me if I'm wrong but won't I basically be slipping the conduit over the wire at each end of the run and just pulling the last few feet through the LB into the box?

nope. conduit needs to be glued & complete before pulling wire through it.

even if youre direct burying the wire, using only conduit above ground, the conduit still needs to be complete beforehand, as required by code. also you dont want to get wet glue on the wire. it will melt the insulation.

 

[u2slow]

125A is another logical step. It's a common subfeed limit for 200A panels. Check your main panel label.

 

[mm08822]

On top of upsizing the conduit, get rid of the 2/0-2/0-1-4 MHF wire and buy individual conductors of aluminum XHHW: 400' - 2/0 Blk , 200' - #1 Blk (or wht) and 200' - #4 Grn. (MHF is XHHW, but the conductors are twisted to form a bundle.

When uncoiled nicely, individual conductors will be very straight and glide into the conduit vs. a twisted bundle that will soon add a lot of drag.

Edit: Woops, I thought this was an end-end conduit run. If not, stay with MHF.

 

[mm08822]

125A is another logical step. It's a common subfeed limit for 200A panels. Check your main panel label.

If that is done, sub panel ampacity needs to increase.

 

[sparky 1971]

On top of upsizing the conduit, get rid of the 2/0-2/0-1-4 MHF wire and buy individual conductors of aluminum XHHW: 400' - 2/0 Blk , 200' - #1 Blk (or wht) and 200' - #4 Grn. (MHF is XHHW, but the conductors are twisted to form a bundle.

When uncoiled nicely, individual conductors will be very straight and glide into the conduit vs. a twisted bundle that will soon add a lot of drag.

I think he's going the direct burial route with pipe on the risers. In post #1, he only needs five feet at each end.

 

[Norcal]

125A is another logical step. It's a common subfeed limit for 200A panels. Check your main panel label.

A 125A breaker is a sizable jump in cost over a 100A.

 

[u2slow]

A 125A breaker is a sizable jump in cost over a 100A.

Depends on the brand. It's only $10-20 more in a Siemens.

 

[laser3kw]

also you dont want to get wet glue on the wire. it will melt the insulation.

Yikes! didn't know that little piece of info

 

[sparky 1971]

nope. conduit needs to be glued & complete before pulling wire through it.

even if youre direct burying the wire, using only conduit above ground, the conduit still needs to be complete beforehand, as required by code. also you dont want to get wet glue on the wire. it will melt the insulation.

Call me a rebel if you want but there is no way I'm going to shove direct burial wire up a riser. Every single time I've run direct burial I pre fit the sleeves, glue it all together, then slide it over the cable, bringing the wire out the LB. Then land the pipe and finish pushing the wire through the LB. If it's going into the bottom of a box, panel, meter, etc. It's the same thing, just no LB.

 

[nadogail]

Are you really planning your electrical installation without a load study?
The idea of running cable without knowing what you be powering can usually mean your selected cable will not be large enough for the load or it will be oversized.
If you are spending someone else’s money you can go large on the cable. If you are spending your own money you can go as big as your budget.

 

[Gone_fishing]

Are you really planning your electrical installation without a load study?
The idea of running cable without knowing what you be powering can usually mean your selected cable will not be large enough for the load or it will be oversized.
If you are spending someone else’s money you can go large on the cable. If you are spending your own money you can go as big as your budget.

I have a good idea of what I will be powering in the near future. And yes the 100 amps will be oversized. But I can't peer into the future and know for sure what I may be powering. There is a living space that will be finished, possibly a hot tub installed and who knows what tools. Could it still be slightly oversized? Maybe. But I hate doing things twice. What I do know is the 100 amps will cover everything I need currently and I absolutely need power in there before winter and 100 amps is the largest I can afford. If 100 amps turns out to be too small in the future then that's just something I have to live with, but I really think it will power everything I will ever have out there.