So I am installing a 125 amp subpanel in a shop I have and I needed to buy a couple of lug kits to connect the ground and neutral wires in my main panel. The lugs Square D sells are rated by amperage it seems. So techincally I would need a LK125AN for this application. Before I realized this, however, I bought two of the LK100AN lugs because these are the biggest ones my local Lowes and supply house stocks. These lugs are sized for up to 2/0 wire which is what I ran for my 125 amp subpanel so everything physically works. I don't really understand the logic behind the 100 amp lugs and 125 amp lugs being different. Both fit the same physical wire sizes. The 125 amp lug has little ears that stick out the side to connect to the ground or neutral bar. The 100 amp lug screws over the top of the bar instead. Even stranger, the 70 amp lug has ears as well while the 150 amp lug sits on top of the bar. So, it doesnt seem like the ear type vs sit on top type design has any affect on amperage rating for the lug. I can't understand how the 125 and 100 amp lugs can have any meaningful difference in amperage rating when they both take the same size wires. Actually, the 100amp lug has a min wire size of 6 gauge and the 125 amp lug has a min size of 14! Now that's really confusing! I am wondering if anyone has any insight into this. Is there a problem with using the 100amp lug for my application? Any thoughts are appreciated. Thank you!
QO Lug Kit Sizing
- Thread starter brianbo
- Start date
Terry D
Well-known member
These are mostly what I use. It is fine what you are using. You have to remember, the neutral only carries the unbalanced load. The chances of having even 70 amps on that neutral is next to impossible. As long as the lug is sized for your wire, you are fine.
Square D 70 Amp Auxiliary Neutral Lug Kit for QO/Homeline Electrical Panel/Load Center LK70ANCP - The Home Depot
Visit The Home Depot to buy Square D by Schneider Electric Neutral Lug AL/CU LK70ANCP
www.homedepot.com
sparky 1971
Well-known member
I agree with Terry. As long as the wire fits, you will be fine. The box stores around here carry the same kits and one or the other has always worked for me.