Installing a surface mount subpanel next to main panel

[maghraby]

Hello!
I am trying to install a 125amps surface mount subpanel next to my main 200amp panel and I wanted to get some thoughts on wire transition from the panel to the wall then subpanel.

my initial plan is to use a SER cable then transition to wall in an electrical box then use a conduit to the subpanel. I believe the subpanel will be 1 feet away.

 

[ddawg16]

??

I'm a little confused. Where is the SER coming from?

 

[maghraby]

From the main panel on a 125amps circuit breaker

 

[wyliesdiesels]

Need more info here.

Is the main surface or flush mount? how about the subpanel?

If flush mount, why not open the wall, drill hole in stud and run it inside the wall?

what size SER are you using?

 

[maghraby]

Main panel is flush, but I want a surface subpanel for easier connections. SER cable should be 1/0-1/0-1/0-2.
Drilling in the stud seems like a better idea. Then I can feed it behind the subpanel?
Do I need to attach/secure it to the stud?

 

[wyliesdiesels]

What are you putting on this subpanel? Do you really need 125a?

As far as strapping goes, depends on how its ran. if it runs through a bored hole in a stud and then is clamped down on both panels, you shouldnt need to strap it.

Running through the stud is easier than transitioning from inwall to conduit. just bring it through the back of the panel

 

[maghraby]

My plan is to add a 60v ev charger for now, then maybe in the future, I would add another one. I could put the chargers on lower amps but it would be nice if both can charge at the same time at highest possible (without tripping whole house)

 

[Norcal]

Just a little bit of info, 15-60A breakers are the same price, it jumps at 70A, jumps even more 80-100A, 110-125A are even more expensive, and need to verify that a particular panel can accept a 125A breaker, not all will which is part of doing the job correctly.

 

[mike93lx]

If this is just for two EV chargers, can you not just add it to the main panel? Especially if you only need one right now.

 

[maghraby]

Just a little bit of info, 15-60A breakers are the same price, it jumps at 70A, jumps even more 80-100A, 110-125A are even more expensive, and need to verify that a particular panel can accept a 125A breaker, not all will which is part of doing the job correctly.

Good point. My main panel can take up to 110A

 

[maghraby]

If this is just for two EV chargers, can you not just add it to the main panel? Especially if you only need one right now.

I was thinking of Tesla wall connector, but it seems that the new generation requires 2 separate circuits. Other EV chargers like JuiceBox can be installed on the same circuit. It’s something definitely to consider

 

[mike93lx]

I was thinking of Tesla wall connector, but it seems that the new generation requires 2 separate circuits. Other EV chargers like JuiceBox can be installed on the same circuit. It’s something definitely to consider

You can always move the charger out to a sub later when/if you get the second.

You may be able to free up space in your main with some tandems, which would be a lot cheaper than a sub, too

 

[Norcal]

110A breakers are a standard size but are a special order item and these COVID times made even standard items hard to get.