Subpanel questions

I have questions regarding adding a subpanel to my existing service. I have installed (3) #3 conductors to my polebarn. The polebarn has a 100 amp panel installed. My house has a 150 amp panel which is full. I installed two piggy-back breakers so I could install one 100 amp breaker in that panel. Next to my existing panel I installed a 100 amp subpanel. (I'm not sure that was necessary) The main reason I did that was so I could later add more circuits to my basement without installing piggy-backs (or whatever they are called).

I installed a 100 amp breaker in the Sqaure D Homeline subpanel, but it says on the cover that the max is one two pole type 70 amp breaker. Also, the box says I need to purchase a neutral lug kit for #3 conductor. Do I have the wrong box? Or am I going about this all wrong?

My understanding is that I need to connect a #3 conductor on each side of the 100 amp breaker of the subpanel to each side of the 100 amp breaker on the main and a neutral from the subpanel neutral bar to the main neutral bar. Since the #3 conductor is so big, is that why they say I need that neutral lug kit? How do I connect the #3 conductor to the neutral lug of the main (Siemens panel)? Do I need a lug kit for that too? Also, does the ground wire connect from the subpanel neutral lug to the ground lug on the main? (The subpanel only has one lug and it's the neutral lug) I am using a Homeline HOM612L100S for my subpanel.

Can someone please help me out with this. I really want to learn how to do this myself if possble.

Thank you,
Brian

 

I'm a bit confused in your post when you are talking about the house subpanel and when you are talking about the barn subpanel. So I can't really follow everything in your post.

But it does seem pretty clear that you cannot put a 100-amp main breaker in a panel with a label that says you can only put a 70-amp breaker there.

You don't normally need a breaker on both sides of a feeder. The upstream breaker should be enough.

Yes, you can buy larger neutral lugs, and apparently you need one.

 

Thanks for the reply.

What do you mean by the "upstream" breaker? (house or barn?)

Sorry for the confusion with my post. I have a 100 amp panel in the barn and a 150 amp panel at the house. The house panel is full so I needed to add a subpanel. My question is, how do I connect the polebarn panel to the main panel at my house? I am using #3 conductor. Should I connect the #3 conductor from the polebarn to a 100 amp breaker on the house main panel?

How do I connect the subpanel (which is right next to the main panel in the house). That subpanel is completely different from the one in the polebarn. The extra one in the house is so I can add some additional circuits to my basement someday.

I hope this makes sense. I'm sorry for my limited knowledge. I am learning as I go.

Thanks again,
Brian

 

I am still confused. Do you have one subpanel or two? You talk about a subpanel right next to the main panel in the house, and you also talk about a pole barn subpanel. How many panels are there all together, and how are they (or will they) be connected to each other?

 

Sorry again John.

Guess you would consider it two subpanels. I have one panel in the barn and one in the house.

My main panel in the house (150 amp) is full so I wanted to add a subpanel. The barn also has a panel that needs to be connected.

I wanted to verify that I'm going about it right. It sounds like I need a #3 lug kit for my main panel at the house.

I cut my #3 conductors already and connected the polebarn to the new subpanel in the house. Now that I know I need to go directly from the polebarn to the main panel in the house, I need to splice the conductors and connect them to the main panel in the house. What's the best way to splice the conductors?

I attached a schematic of my project.

Thanks again,
Brian

 

So let's take this one step at a time. You need two new double-pole breakers in your main panel, one to feed the adjacent subpanel, and one to feed the pole-barn subpanel.

Is this what you have so far?

 

Yes, that's exactly what I need to do. Were you able to view my attachment ok?

Thanks,
Brian

 

Attachment?

 

I attached a schematic of my project. Here it is again...

(I can't imagine it would be too big...it's just a JPEG)

 

You cannot attach images. The best you can do is to post your image to your own web site and reference it.

It you look closely at the box where you enter the name of your jpeg file, you'll notice that it says, "Maximum size: 2 bytes". That's not big enough for anything.

 

Ok, gotcha. Here's the link to my site:
http://24.247.104.33:8100/Electrical_Plan.jpg

Thanks,
Brian

 

John-

I was wondering if you had trouble getting to that site? I hope you haven't given up on me!

Another person suggested for hooking up ONLY the polebarn, that I unhook the #3 conductors from the subpanel at the house and hook them up directly to a 100 amp breaker on the main panel in the house. ( I won't worry about the second subpanel in the house for now. I just need to get the polebarn hooked up)

The problem with that is I need to splice that #3 conductor to make it over to my main panel. The splice would be inside of my 1 1/2 conduit wrapped carefully in friction tape. Is that ok to do? (This is all inside my house)

If someone could help me answer these questions, It would be very much appreciated.

Thanks again,
Brian

 

Yes, I was unable to get to that site.

It is never okay to splice inside conduit. If necessary, install a permanently accessible box and make the splices there.

Each of the two feeders should have its own breaker in the main panel.

 

Thanks for the reply John.

When you refer to a "permanent box" what is that exactly? Is it a special type of box that I can purchase? Or are you referring to a subpanel box?

Thanks,
Brian

 

I didn't say "permanent box". I said "permanently accessible box". Any kind of junction box can be used, as long as you can get to it any time in the future without taking apart the building.