Should I future proof a new electrical panel?
My townhouse needs a new electrical panel. The existing panel is the Stab Lock style that has some known issues and the electrician is recommending panel replacement as part of a Level 2 charger installation.
What would reasonably be added now to “future proof” the panel for features such as:
1) Solar – We have a roof replacement happening in ~8 years
2) Vehicle to home/grid – My current EV doesn’t support it, but maybe one day I will have the money to own one that does?
3) Battery backup
4) Anything else?
is there a better panel to buy? or are all these things described above basically add-on boxes that don’t really need to be part of the panel anyways? Am I better off holding off for the tech to get better and invest when I need it? Or is there an opportunity to pay a little extra now to save a lot of work later?
Note
Upgrading to a 200 amp panel is out of the question as the cables are direct buried under the slab.
We are installing a load management system with the level 2 charger, so that aspect is covered
Thanks for your thoughts!
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With 200 amps immediately off the table, I don't see any reasonable degree of future-proofing. Forget about electric appliances and heat pumps for primary heating and cooling unless your house is tiny and/or has PH levels of airtightness and insulation. Where is the panel in the house? Is it possible the service entrance conductors could be routed through an attic or exterior wall? I ask because the least-expensive time to boost panel capacity and available amps is when doing a new service-entrance.
Even with 100A service, you can future proof. Get a 200A panel with a 100A main, you'll have to buy the smaller main separate and swap it out. The cost delta for this is pretty small and well worth the investment.
This gets you 200A busbars so you can install more PV or battery if you ever want to. Also try to get a bigger panel with more breakers than what you currently need, the extra cost of the larger panel is pretty much noise.
@Patrick Not an issue to run an all electric house off a 100A service. People overestimate how much power a houses uses. Add in a load managed EV charger, you'll have no issues.
This gets my vote. Install the biggest panel that will physically fit, derate the master breaker if necessary. You never regret having more slots.
I agree. I requested a peak load analysis from my electric utility and it came back at 7.09 kW over the last 12 months. After adding a 25% buffer this works out to about 35 Amps. I heat the house with a 2 ton heat pump which includes a 10 kW aux heater that rarely comes on. Induction stove and electric dryer.
Can mainstream houses really be all electric in cold or mixed climates on 100 amps without active load management on the whole house Akos? Are you considering people with well, sewage, and sump pumps? Resistance dryers, ranges and water heaters?
You'll have to run the demand calculation for the place. A typical heat pump is between 3000 to 5000W (12A to 20A) of demand which is not far off what is assigned to an AC unit, so not a lot. You can now also get heat pump water heaters with a 15A element which significantly reduces the demand.
The one you won't have room for is a car charger, maybe something like 15A, but with demand management you can go more.
As for the rest, well pump loads and such don't add up to all that much demand.
This is based on the Canadian code, I know NEC is slightly different.
I don't think I've ever gotten close to 100A after adding a level 2 EV charger. That's with no load management and a fully electric house in zone 5.
The location is Vancouver Canada.
Based on the code accepted heat loss models the townhouse should be fine with a 24,000 btu/hr system for heating (the Dana GBA method comes out about 30% lower), translating to a max current of ~20 amps. Based on the Canada Electrical Code calculation method a 100 amp should be able to support a L2 charger (load managed), heat pump and a 15 amp hot water heater (Code only cares about the max rated draw, being a HPHW doesn't matter).
Surprisingly the code also allows you to de-rate the electrical room shared by the townhouses. Ie the 8 units are fed by only 400 amps. Even then the math works.
We will see what reality throws at us, but code says we are ok.
I can post a calc sheet if you are interested.
Those stab-lock panels had more than just "some known issues". They ARE an issue. Replace that thing ASAP. Total garbage. On the plus side though, there is a huge market for the breakers from those old panels, so I suggest to sell them on Ebay and you'll probably be surprised how much money you can make that you can put towards your upgrade project.
Another vote here for a 200A panel. All you need to do is put in a MAIN BREAKER sized for the wire you have. This might mean you need to get a 200A "main lug" panel, which will have no main breaker, then get a main breaker kit for it of the size you need and install it in the main lug panel. This is not a big deal to do, and the main lug panels are already setup for this.
Get a COPPER BUS panel. This will get you copper busbars instead of aluminum. The copper busbars are much better, and don't cost much more, if anything at all.
Personally, I like Siemens panels and usually design with their stuff commerically. You can get their stuff everywhere, it's good quality, and they seem to gouge you less on parts bought seperately down the road. Many/most suppliers of panelboards will give you a deal when you bundle breakers with a panel, but will charge you a LOT MORE per breaker to buy additional breakers seperately in the future.
Be carefule with the "circuits/spaces" difference. A "40 circuit, 20 space" panel will have space for 20 breakers, but will need you to use tandem ("skinny") breakers toget all 40 circuits. The best way to go is to get a 40 space panel, but ideally one that can also handle 80 circuits to let you use tandem breakers in any space in the future if you want to. Most panels are keyed so that tandem breakers can not be used in all spaces, and while you can get special tandem breakers that are keyed to be able to fit anywhere, they cost more than the ones that are keyed to be able to only fit in the "right" locations.
BTW, "derating" that you mentioned is called "demand factor" and is commonly used in multiunit residential buildings. The general idea is that not everyone will be baking someting in their oven at the exact same time (as an example), so you don't need to allow for capapacity to run all the ovens 100% all the time. This doesn't work as well with longer duration loads, so EV chargers could potentially be an issue if enough of your neighbors plan to add them too.
Bill
Thanks for the heads up on the stab lock panels. Do you know if any good authoritative sources on the issue? I lack the “riz” of the certain elected officials and my fellow strata members demand we make thoughtful, fact based, evidence based decisions instead of just taking my word for it.
The challenge is that the panels are not actually on a recall, nor is there any government directive to replace them. Have there been any studies you know of?
Thanks again.
Looks up the issues with the Federal Pacific ("FPE") panels from several dacades ago. The usual issues, besides the famously poor performing breakers, was that the relatively small stab and tiny latching notch weren't secure. It was common for those breakers to pop out of the panel whenever you opened the cover, and you'd have to use the cover to kinda push them back in as you closed the panel. Very, very poor design. The loose stab would then get hot under load, which would make the problem worse. Avoid those like the plague.
The modern "1"" breakers have much larger mating areas for their electrical connections. The big manufacturers are all similar designs, often even interchangeable, although you aren't allowed to do that since the panels are listed for use with THEIR manufacturer's breakers. I like Siemens stuff, but Square D is good too. I just find Siemens to be a bit better priced for similar quality. You can go to Square D's "QO" line too, which are their commercial breakers, but you can get residential panels that use those. QO panels are a bit more compact for a given number of circuits, but otherwise not a lot different. I usually just use the "regular" 1" stuff.
My recommendation would be to replace all the stab lock stuff as part of your upgrade project. The stab lock stuff is most at risk when running heavy loads of long duration, which is exactly the kind of load you'll see from EV chargers and other large loads common with electrification projects. Since you're probably going to need to do a lot of electrical work anyway, replacing the panels shouldn't actually add much cost to the project.
Bill
I also should mention we are going with a two level load management system. There will be current sensors in the electrical rooms AND the EVSE units being fed from individual panels. So EV’s will only get power if both systems have spare capacity.
I've never heard of copper bus bars as an option. Can they be retrofitted on a Siemens panel?
No, you would need to replace the panel. The copper bus bars are only in the "hots", the busbars that are energized that the breakers plug into. The ground and neutral busbars, the ones with all the screws in them, are still going to be aluminum either way.
I prefer copper busbars whenever I have an option. The cost difference, at least with Siemens residential panels, is usually very small, often only a few dollars if anything. The commercial panels I design with at work have so little cost difference that my supplier doesn't even bother stocking the aluminum busbar panel variants.
Bill
I'll chime in on the "is 100amp enough", it definitely can be. I live in Climate Zone 6, 1955 1100sqft ranch, new windows and an added layer of batts in the attic, other than that it's leaky like titanic.
I completely replaced all the electric in the house, but the service in was 100amp underground, going under the driveway. Like another user mentioned above, I installed a 200amp panel, and then a 100amp service disconnect panel (the 200amp panel couldn't be configured with 100amp breaker).
I expected I would upgrade the service later, but after 8 years in our house, I no longer will.
- We have an all electric house, normal electric range, microwave, side by side fridge, 1x 12k Mitsubishi Hyper Heat Mini, 1x 9k Hyper heat Mitsubishi Mini, Conventional electric dryer, and 500sqft of finished basement theater heated with 2500watt's of electric baseboards (not 24/7)
- Critically, we bought a Tesla Model 3 a year ago and use the Wall charger at 40Amps.
I have never had an issue. We have On Peak/Off Peak Electric Billing, so the Tesla never charges between 2pm-7pm, Weekdays.
Thanks. I love getting real world examples of seeing it work. It’s a little scary pushing ahead with electrification of our complex. What if I’m wrong? The calcs make it look very doable, but what if the real world has something else in store? We are also dealing with shared electrical rooms. The average feed works out to only 50 amps per unit. 400 amp feed shared by 8 units with 100 amp panels.
Electrical things are usually very "engineerable", since it's easy to calculate pretty much everything you need to know. Assuming you have sufficient capacity on your existing supply, all of the downstream design you need to do should be pretty straightforward. You'll have some demand factors that will work in your favor, since it's unlikely everyone will be running everything all at the same time. From what you've posted here, I think you're probably OK, I'd just be concerned with the EV chargers. EV chargers are large, long-term loads (typically hours of charging per cycle), and most people WILL want to charge overnight, so around the same time of day. Most EV chargers can be set for reduced demand though, so you could potentially put in a sort of distributed load shedding system that would monitor the main feed, and automatically reduce the EV charging load if the main service gets up into a higher than desired load level.
Bill
I'm not sure where you're at or what your electrical code are, but I'll throw something into the mix: consider a 200A main disconnect switch
This is a switch between your meter and main panel. And the 200A is for if you ever decided to upgrade the service.
I'm not sure, you may already have this. I think many states require an exterior shutoff? (Bill can you comment on this please). But in my neck of the woods in Canada, it's not a requirement. I put them in optionally because I learned this from a commercial electrician. Most resi's don't consider it.
The purpose of this is, if in the future, you need to make changes before the panel, you don't have to call/pay for the electrical supply authority to disconnect your meter.
Some examples of changes are adding an automatic transfer switch or gateway before the panel, which allows you to power the whole home from a backup power source and eliminates the need for a subpanel which is dedicated only for backup circuits. Or if you ever wanted to swap your whole panel out, and say upgrade to a smart panel (this is a thing and will probably be more viable in the near future). Or another example is if you wanted be able to sell your renewable energy to the grid, you would need that system tied to the mains before your panel.
Jamie
Correct, outdoor "emergency main disconnects" are required in newer versions of the code, I think starting with the 2020 edition. If you're local municipality is on that revision, they'll need that disconnect. You need to size that for the wire you run to the downstream panel though, so if you put in a 200A disconnect, you have to size the wire for 200A too.
Note that when adding these seperate disconnects, the ground/neutral bonding point becomes the location of the disconnect, so you need FOUR WIRES from that disconnect to the panel, and the panel inside has to have seperate ground and neutral busbars. Any panel can be setup this way, but sometimes you have to buy an additional ground bar kit (usually not very expensive).
Bill
Thanks for the advice on that. For our block of townhouses we have an electrical room which houses all of our meters and the main breaker for all of the fed homes.
If that is a fused disconnect in the electrical room for your place, you can add a 200A panel without modifications.
In terms of load, demand calculation is very conservative. If the numbers say it will work, you'll have no issues especially if the EV chargers also monitor the main power feed.
+1 to adding a 200A main disconnect switch.
I'm (slowly, very very slowly) rewiring my house, which has also involved running power to a separate shop and a hot tub, and having that main disconnect outside has saved me a LOT of hassle for a very minimal upfront cost. Even if it's not required, it's worth it.