NEMA 14-30 with 30A breaker

[Kisuna]

Hello all,

I am currently looking into my charging options before I take delivery of my Model 3. I recently opened up my panel box and see an empty slot here. I was planning to just buy a 30A tandem breaker and install it in the empty slot to a NEMA 14-30 outlet. However I don't see that slot in the diagram in the picture attached as well as a sticker in the empty slot that says 'do not install breakers here'. Wondering if anyone here might know why this slot is empty. My uneducated guess was because one of the wires to the main switch was blocking the space.

Thanks in advance,

 

[jdcollins5]

Are there more than one set of wires going to the main breaker? Do you have another sub-panel feeding from this panel?

What looks like a splice lug is blocking the breaker space.

 

[rwiegand]

You are a pretty clear candidate for a subpanel, it can sit right next to your main panel, at least a few wires are probably long enough that they can be re-routed to the sub to make room in the main box for a new tandem breaker. Alternately, and almost certainly a better idea, you could re-route the service entrance to a new panel and make the existing panel the sub.

That really does look like a subpanel repurposed as a main-- certainly odd, in any event. An electrician will help you to do something both safe and legal with it, shouldn't cost all that much. Parts for making a new main panel, converting the existing one to a sub would only be a couple hundred bucks. With labor it should be under a kilobuck.

 

[dmurphy]

That panel is only rated for 10 poles. There’s no punch-out on the cover panel for those slots you mentioned, and in fact it’s labeled as such.

As @rwiegand said, this is a prime candidate for a sub panel. Frankly, this panel is what I’d consider not just completely full, but overfull.

(I’m not a fan of tandem breakers. You can’t just replace a standard with a tandem - have to make sure the panel allows it, and in which slots at that.)

Might just need to bite the bullet and update to a new panel.

 

[MN-MS100D]

And you only have a 100 amp panel, already with a 60 amp breaker presumably for A/C or whatever is below the load center panel..

 

[Kisuna]

Are there more than one set of wires going to the main breaker? Do you have another sub-panel feeding from this panel?

What looks like a splice lug is blocking the breaker space.

Hey yes, there is a sub panel feeding from this panel. But that subpanel is also full with no empty slots.

 

[Kisuna]

Seems like dmurphy and rwiegand are recommending a sub panel which I already have but its full. So should I look into a 2nd sub panel? Or should I replace two of those single pole 20a breakers for a double pole 20a breaker, which will leave me space for another 30a tandem breaker?

 

[jdcollins5]

Seems like dmurphy and rwiegand are recommending a sub panel which I already have but its full. So should I look into a 2nd sub panel? Or should I replace two of those single pole 20a breakers for a double pole 20a breaker, which will leave me space for another 30a tandem breaker?

Unless you have experience with load calculations, I would recommend having a licensed electrician take a look at this.

 

[rwiegand]

+1 on having an electrician look at it. My bet is that they will tell you to install a new main and feed your two existing panels from it as subs. Even if you don't immediately want to upgrade your service you can install a new main panel that would be capable of 200A by swapping the incoming wires and a new main breaker. A load calculation will tell you whether you need a bigger service to support the car in addition to your previously existing loads.

 

[Kisuna]

Gotcha, thank you all!

 

[davewill]

+1 on having an electrician look at it. My bet is that they will tell you to install a new main and feed your two existing panels from it as subs. Even if you don't immediately want to upgrade your service you can install a new main panel that would be capable of 200A by swapping the incoming wires and a new main breaker. A load calculation will tell you whether you need a bigger service to support the car in addition to your previously existing loads.

It would probably be equally effective to replace that panel with a bigger main. Kind of depends on the age of that panel, and whether there's any benefit to keeping it.

 

[rwiegand]

It would probably be equally effective to replace that panel with a bigger main. Kind of depends on the age of that panel, and whether there's any benefit to keeping it.

Sure, just depends how long the wires are and whether it can be done without adding splices (I've mostly not been so lucky!). The electrician on site will figure that out.