Upgrading Electrical Panel - Newer Home

Upgrading Electrical Panel - Newer Home

Anyone else forced to upgrade their electrical panel for more circuits?

Wife and I are in a home built in 98' with a 200 amp panel. Went to plug in my shiny new Model 3 which tripped three breakers. Electrician comes out, says that every slot on our 20 slot breaker has tandem breakers which is overloading the system. Say's he's never seen a 200 amp panel for a 3,500+ SF home with so few circuits, and we must install a larger electrical panel.

I didn't get the sense that he was trying to up sell me, and it literally takes 2-3 weeks to get an electrician out in our market as everyone and their mom is bogged down with work.

Just seems incredibly frustrating to have to spend $2.5K on a new panel for a home built so recently already with a 200 amp panel, and then another $800 to install our HPTWC.

I don't know if i'm venting, or want some affirmation that this is normal'ish, or a hug. Either way, i'm here. | 07/12/2018

When I switched to EV, I switched from 100 amp to 200 amp panel. If you're in an all electric house, then 200 amp does seem close to the limits, but it's hard to tell without a lot more info. The bigger issue is a panel with no slots available. Seems most builder install a panel with too few slots. 200 amp service may be fine, even with EV charging (as it is normally done late at night), but without breaker slots, you'll either need a sub-panel or a new panel. Code changes may also force a lot more costs if you replace the panel. Cheap breakers are often required to be replaced with Arc-faults, which are 10x more expensive. Good luck!

Frank99 | 07/12/2018

Yeah, that's what always p*sses me off about construction - saving a few bucks on infrastructure that I have to live with for 10 years. For example, a 40-space meter panel costs $250:
and a similar 20 space panel costs $150.
I would have paid an extra $200 to have the bigger one installed.

Anyway, yes, it's likely that your panel barely met the National Electrical Code standards for the electrical needs of your house when it was built. Over the last 20 years, I'm guessing additional circuits were added filling the panel. If all your spaces are full of tandem breakers, you really don't have a choice but a panel upgrade.

As TeslaTap noted, you may need to replace some breakers with AFCI breakers. A normal breaker might be $5, but an AFCI is $50 - fortunately, you probably won't need more than a handful of them. Your electrician will know.

Are there any circuits that aren't in use - for example, a 240V breaker for an electric dryer when you're currently using a Gas dryer? It's easy and much cheaper to repurpose existing breakers than replace the panel.

Frank99 | 07/12/2018

Oh, another option to discuss with the electrician is to add a subpanel rather than replacing the main panel. Add a 100A subpanel, and move all the lighting or 120V outlets into it, freeing up space in the main panel for a breaker for the subpanel and a breaker for your HPWC.

reed_lewis | 07/12/2018

I added a subpanel with a 100 amp breaker into which I moved a bunch of regular circuits. Then I left the 240 volt circuits in the main panel.

Much easier!

I had a 40 slot non-duplex panel which did not allow duplex breakers (two circuits on a single connection to the panel). My sub panel does allow duplex breakers, so I moved a lot of household circuits into that which opened up enough to put in two car chargers, 4 240v A/C breakers, and a 240V stove breaker. That uses up 14 of the 40 spots in the main panel...

Remember there are quad breakers which can supply either 2 240V circuits and 2 120V circuits, or two 240V circuits. That might be what you need!

reed_lewis | 07/12/2018

ooops. The last paragraph should read:

Remember there are quad breakers which can supply either 1 240V circuit and 2 120V circuits, or 2 240V circuits.

Please ignore what is in the previous post in terms of quad breakers!

Gvalencia4478 | 07/12/2018

@frank99 and @reed_lewis thank's for the info, appreciate it. I'm figuring it's just a bullet I have to swallow. I asked about repurposing several switches to make room, but either way everything is tapped out and we just moved in, expecting to "grow" within the next couple of years with more needs/devices/EV's.

Also asked about a sub panel, and was told that the work required to rewire the current panel (which was sloppily done, apparently, not the first electrician to say that in the 9 months we've been in the home) into a sub panel would end up costing near the same as just adding a new panel.

Seriously though, another $1 - $200 during construction could have saved me $2.5K now.

Yodrak. | 07/12/2018

" Went to plug in my shiny new Model 3 which tripped three breakers."

Three? Which were they? And what type of circuit did you plug in to.

"Remember there are quad breakers which can supply either 2 240V circuits and 2 120V circuits, or two 240V circuits."

I haven't seen a quad breaker that could handle 2-240 v and 2-120 v circuits (a total of 4 circuits), but my 200 amp panel was full even with a 100 amp subpanel to handle the 120 v outlet and lighting circuits for half the house, so I replaced my 240 v 30 amp electric dryer breaker with a 30-50 amp quad breaker as a way to supply my EVSE. I have two AC units, but use gas for the cooktop and the hot water heater. I charge day or night and have not tripped my main breaker.

Yodrak. | 07/12/2018

Sorry Reed, I missed your correction on the quad breaker.

sschaem | 07/12/2018

Can you lower the amp limit on the model 3 to avoid tripping the breaker ?
(what else is on that circuit ? you might have to lower your amp limit by much)

Do you have an electric dryer ? Maybe you can bring that 240v 50A circuit to your garage.

MaxEV | 07/12/2018

If you want to charge your Model 3 at its maximum rate on the wall connector and have additional capacity for other future electrical loads in your house, then a panel upgrade probably makes sense at this time. However, if you wish to save money in the short term, you should be aware that the wall connector can be dialed down as low as 12 amps (with a 15 amp breaker) at 240 volts. If your daily commute driving needs are modest, that could be sufficient for you for now. You would just need to free up at least one slot in your panel by getting rid of one non-essential device. Perhaps you can replace an old electric stove with a gas stove, or an old electric dryer with a gas dryer, or find a circuit connected to a device that isn't still active.

By the way, my understanding is that you might qualify for a U.S. federal EV charging equipment tax deduction *if* the deduction is (retroactively) extended again to 2018 per this link:

Yodrak. | 08/12/2018

"Do you have an electric dryer ? Maybe you can bring that 240v 50A circuit to your garage."

Electric dryers are typically on 30 amp circuits. Yours might be an unusual case if its on a 50 amp circuit.

sschaem | 08/12/2018

Still, having a dedicated 30A 240v circuit for the car is better then tripping a shared 15A 120V circuit.

24A / 240v for a model 3 is pretty decent, so I'm not sure doing a panel upgrade is needed if its cheaper to bring the 30A/240v circuit to the garage.

So the recommendation stand.

mike3 | 09/12/2018

“disclaimer”: I am a licensed residential electrical contractor, and a certified Tesla HPWC installer.

The problem described is very common, in all vintages of home, and one of my massive pet peeves. A bit of clarification:

1. There is virtually no connection between service capacity – 100 amps, 150 amps, 200 amps, etc – and the number of breaker spaces. Those are two entirely unrelated variables. Because you don’t have enough spaces does NOT mean you don’t have enough power. Two different things.

2. In my decades of experience, “Twin” or “tandem” breakers (a totally different thing from “dual” or “double” breakers) -- by which you manufacturers allow you to squeeze two breakers into the space of one “standard” breaker -- fail at about 5 times the rate of standards. Literally. 5 times more often. Plus, when they fail they often fail in a way that damages breakers nearby, and possibly the panel itself. They suck. Not to put too fine a point on it.

3. The OP writes that the model 3 “tripped three breakers.” It’s unclear what that means. What kind of breaker? (size, single or double, etc). What kind of circuit? Was it the circuit the car was plugged into? If it was a standard 120-volt circuit, what size breaker, and what else was on that circuit? Was it 3 all at once? That’s weird. Was it one, then it was replaced, then another, then it was replaced, etc. That’s a sign that the circuit on THAT breaker was overloaded.
It is NEVER a good idea to plug an EV – any EV – into a random 120-volt circuit. The minimum would/should be a 20-amp dedicated (not shared) circuit. Even then, be prepared to wait a few days for charging.

4. One commenter post on meter/breaker pricing differences. It’s unclear the OP had a meter/breaker combination unit; most people, they’re separate. Here’s two directly relevant comparisons, both 200-amp breaker boxes:
200 amps, 40-spaces - $119
200 amps, 20-spaces - $99 [this one will handle “40-circuits,” but only by using ALL twin breakers.]

So, the OP is absolutely right to be angry. Some jackass saved $20, and now you have to spend 100 times that. Seriously, it’s one of my pet peeves – and I’m the one who replaces them.

And sometimes a sub-panel is a viable option, and shouldn’t cost $2k.

reed_lewis | 09/12/2018

I had a sub panel put in with about 16 circuits moved to it, and the total cost from a licensed electrician was about $800. To me it should cost less than having to remove the entire panel and put a new one in.

Frank99 | 09/12/2018

Great post, Mike3. Thanks.