Leviton EVSE, do I need to upgrade my panel to 250 or 300A?

[cossie1600]

I am in the process of getting a house build. I assume they will come with a 200A panel, but do I need to ask them to do a 250 or 300A if I were to add a Leviton EVSE since that requires 50A breaker by itself. The house will have gas dryer, so I think one less load?

 

[miimura]

I am in the process of getting a house build. I assume they will come with a 200A panel, but do I need to ask them to do a 250 or 300A if I were to add a Leviton EVSE since that requires 50A breaker by itself. The house will have gas dryer, so I think one less load?

I had a custom house built that was finished at the end of 2012. I told the electrician to put a NEMA 14-50 on each side wall of the garage for future EV charging. I left the wiring and breaker details to them. I had previously talked to the PG&E service engineer and we agreed that a 400A service would be appropriate because there is no service level between 200A and 400A for the feed from the pole. When I checked on the house during electrical rough-in I found that the electrician had put a 200A panel. I argued with him for a while about the panel and we went over all the loads and appliances. I talked to my solar installer and after I told the electrician that the solar would require two 20A double pole (240V) breakers, he finally agreed that we exceeded the 200A panel. The additional charge for taking out the 200A panel and installing the 400A panel during electrical rough-in was about $1,500. I'm glad I did it.

My 240V loads:
50A kitchen range (not currently used)
30A Upstairs A/C (not currently used)
30A Downstairs A/C (not currently used)
30A Clothes Dryer (not currently used)
50A EVSE
50A Spare Garage Outlet (not currently used)
125A Sub-Panel for most household circuits

The range and the clothes dryer are gas but I put the electrical there anyway for possible future use. I thought I might be able to get away without A/C by cooling the house with fresh air at night. However, I was not nearly rigorous enough with the insulation specs and budget to make it. I will probably install the compressor unit for the upstairs soon. All the A/C was pre-plumbed and pre-wired.

 

[Michael Bornstein]

Simple solution: Put the 50A lines on a separate meter. PG&E charges $50 + $4/mo for the second meter, but you can then get the very low E9-B rate for the cars (under 5 cents/kWh). That way you can have a 200A panel for the house and a separate 100A panel for the two EV lines, both fed from your 400A service.

 

[fooljoe]

Your panel needn't be as large as the sum of all the breakers within; rather you would perform a load analysis that factors in the level and time of the actual expected usage. Since EV charging is typically done in the middle of the night when no other 240v loads (like A/C, range, dryer) would be in use, it's very unlikely to push up the size of panel needed. As long as there's room for all the breakers you'd probably be fine with whatever the panel recommended for the rest of the house would be.

I have a 50 amp circuit for my Rav, a 30 amp circuit for my Leaf, a 50 amp circuit for my induction cooktop, a 30 amp circuit for my electric oven, a 40 amp circuit for A/C, a 20 amp circuit for solar (this actually subtracts from the total load), and all my 15/20 amp 120v circuits on one 125 amp panel, and have never tripped the main breaker or had issue with inspections. Maybe sometime I'll try charging both cars with the A/C blasting and cooking some stuff while it's dark out just to make sure that main breaker works! :lol:

That said, I'll second Michael's idea to get a 2nd meter installed for EV charging. I'd never recommend a 2nd meter for existing construction, but if you're going to build a house from scratch you might as well make yourself eligible for the cheapest possible rates. Although I think if you're going to have solar it might actually make more sense to have the EV charging and solar on the same meter - but it'd be relatively easy to switch the circuit from one meter to the other if that turns out to be the case, assuming they're collocated.

 

[cossie1600]

Yes I will have solar too, so it doesn't make sense to two panel. Since my dryer is gas, I think I have no problem doing a 40a circuit for the EVSE. The issue is that the Leviton needs 50a, not sure if they will be able to do it. I guess I will talk to them and see how much the upgrade is. If it is less than $1k, i will probably just upgrade it.

 

[miimura]

Yes I will have solar too, so it doesn't make sense to two panel. Since my dryer is gas, I think I have no problem doing a 40a circuit for the EVSE. The issue is that the Leviton needs 50a, not sure if they will be able to do it. I guess I will talk to them and see how much the upgrade is. If it is less than $1k, i will probably just upgrade it.

I recommend putting in two 50A circuits in the garage. Then let the electrical contractor figure out how big a panel you need based on the sum of everything in the house.

As for the second meter, I considered that too when I was talking to the PG&E service engineer. However, I knew I would be getting solar and if you get a second meter, you cannot use the solar on the house meter to offset your EV charging bill. Net Energy Metering only applies to a single meter. The expensive way would be to get the second meter (which gives you a second baseline) and divide the solar so some of it feeds into the EV meter. Possible, but probably not worth it.

Edit: I thought about this some more and the second meter makes even less sense now because PG&E Schedule E-9 is closed. The only EV rate is Schedule EV, which has no usage tiers. Part of the benefit of getting another meter was that it gave you another baseline so you could charge at a lower price tier. Now that you can't get E-9, baselines don't matter and you only pay by time of day, not by usage tiers per month. The only remaining beneficial scenario for two meters is if you don't have solar, but do run a lot of air conditioning in the afternoon and you don't want that on TOU.

 

[buickanddeere]

Assuming this is a North American single phase 120/240 electrical service ?
We run a 20Kw electric furnace, two fridges, a freezer, 4.8Kw water heater, 4.8Kw clothes dryer, a 300amp AC/DC Hobbart Welder, 3HP air compressor, water pipe trace heating, shop electric heat, 1 HP electric well pump, a tractor block heater and two vehicle block heaters. All from a 200amp panel. Never came close to having everything on at once and overloading the mains. I have a 309A and a whole pile of additional credits.
Last Dec electrical bill hurt however at $940 .

 

[Michael Bornstein]

PG&E Schedule E-9 is closed. The only EV rate is Schedule EV, which has no usage tiers.

I am sorry, I didn't realize that E-9B is no longer available. I already have the second meter that I specifically had put in (at some expense) to make use of the lower rate. How will that effect those of us that are currently using that rate? How long will we continue on E-9B until they convert us to EV?

 

[cossie1600]

As I said, I can probably get away with the 200A panel, but it might be easier to put 400A in if the cost isn't that much more since it is being built now. I figure the biggest load would be

50A EVSE
50A Stove/Oven (I am on natural gas)
30A Central A/C
20A Fridge
15A Washer
10A Garbage Disposal
15A Rest of the house
10A Rest of the house

Seems a little tight no? Oh crap, I also forgot the 20A for the solar panel

 

[fooljoe]

No, that doesn't seem at all tight. But that said you might as well go big. A house is meant to last 50+ years, and it's not hard to imagine at some point in the not-too-distant future the occupant of your house might want to charge 2 or 3 EVs, each with 20+ kw chargers, so why not go for 400 amp now, as long as the cost isn't too egregious? And while you're at it add in at least one more 50 amp EVSE circuit to support multiple EVs, or at least run a big sub-panel to the garage.

 

[miimura]

As I said, I can probably get away with the 200A panel, but it might be easier to put 400A in if the cost isn't that much more since it is being built now. I figure the biggest load would be

50A EVSE
50A Stove/Oven (I am on natural gas)
30A Central A/C
20A Fridge
15A Washer
10A Garbage Disposal
15A Rest of the house
10A Rest of the house

Seems a little tight no? Oh crap, I also forgot the 20A for the solar panel

You need to separate the 240V loads from the 120V when you add them up. Also, as said earlier, the electrical code allows for more than the straight addition of the breaker capacities in the panel compared to the panel rating. Some kinds of loads are derated while others are not. For example, an electric oven is an inherently intermittent load, while an EVSE is not.

240V:
50A EVSE
50A Stove/Oven (I am on natural gas)
30A Central A/C
30A Dryer
20A Solar

120V:
20A Fridge
15A Washer
10A Garbage Disposal
15A Rest of the house
10A Rest of the house

I'm pretty sure you will have at least 4 or 5 more 15A 120V circuits. You don't have a furnace, bathrooms, kitchen, bedrooms, etc. listed, which all have to be separated.

Also, one more time, even though you have a gas clothes dryer and plan to use one for the foreseeable future, I strongly recommend you put a NEMA 14-30 at the dryer location along with the gas. While you're at it, pre-wire the garage for a second EVSE, or like fooljoe said, put a sub-panel in the garage. Having the sub-panel there makes it much easier to add whatever you need later - mostly because people don't mind exposed conduit in their garage.

In any case, you will probably be able to do all that in a 200A panel. As long as that already includes the things like the dryer and second EVSE for future use, there is no need to go with the bigger panel.

 

[Michael Bornstein]

PG&E Schedule E-9 is closed. The only EV rate is Schedule EV, which has no usage tiers.

I am sorry, I didn't realize that E-9B is no longer available. . How will that effect those of us that are currently using that rate? How long will we continue on E-9B until they convert us to EV?

In answer to my own questions, here is the quote from P.G. & E.:

E-9: This option is no longer available for customers; however, existing customers on E-9 may elect to stay on E-9 until at least the end of 2014 (exact date is dependent on actions being taken by the California Public Utilities Commission), at which point they will transition to another applicable rate schedule.

BTW, The off-peak EV-B rate is double the E-9B rate, and the peak rate is comparable to gasoline ($.40/kWh)

 

[miimura]

PG&E Schedule E-9 is closed. The only EV rate is Schedule EV, which has no usage tiers.

I am sorry, I didn't realize that E-9B is no longer available. . How will that effect those of us that are currently using that rate? How long will we continue on E-9B until they convert us to EV?

In answer to my own questions, here is the quote from P.G. & E.:

E-9: This option is no longer available for customers; however, existing customers on E-9 may elect to stay on E-9 until at least the end of 2014 (exact date is dependent on actions being taken by the California Public Utilities Commission), at which point they will transition to another applicable rate schedule.

BTW, The off-peak EV-B rate is double the E-9B rate, and the peak rate is comparable to gasoline ($.40/kWh)

This line of discussion should be moved to another thread...

Yes, the peak rate on either of these plans is very high, but that's the purpose - they are using the pricing to encourage Off-Peak charging which utilizes inherently cheaper electricity. The highest Peak rate on E-9B is actually $0.57197/kWh which is even more punitive than Schedule EV.

Here is the detailed comparison:

EV-B
Summer Peak $0.39116 M-F 2pm-9pm, Sa-Su 3pm-7pm
Summer Part-Peak $0.20883 M-F 7am-2pm, 9pm-11pm
Summer Off-Peak $0.09790 All Other Times
Winter Peak $0.26238
Winter Part-Peak $0.15876
Winter Off-Peak $0.10053
Off-Peak is 11pm-7am weekdays and all weekend except 3-7pm

Since E-9B is Tiered, I'm not going to put all the numbers for the Peak and Part-Peak because by definition, it's dedicated to EV charging which should be Off-Peak except in "emergencies".
I'm using baselines for climate zone X, which is the whole strip between the Central Valley and the immediate coastal area, which allows 11.0kWh/day Summer, 11.7kWh/day Winter.

E-9B
Summer Off-Peak Baseline, First 330kWh, $0.04751/kWh, $15.68 total
Summer Off-Peak Tier 2, 331-430kWh, $0.06679/kWh, $6.61 total
Summer Off-Peak Tier 3, 431-660kWh, $0.26414/kWh
Summer Off-Peak Tier 4, 661+kWh, $0.30414/kWh

Winter Off-Peak Baseline, First 351kWh, $0.05665/kWh, $19.88 total
Winter Off-Peak Tier 2, 352-456kWh, $0.07591/kWh, $7.97 total
Winter Off-Peak Tier 3, 457-702kWh, $0.27329/kWh
Winter Off-Peak Tier 4, 703+kWh, $0.31329/kWh

Off-Peak is Midnight-7am and all weekend except 5-9pm

Let's arbitrarily say that your EV charging takes 430kWh per month. That is enough for about 1,150 miles per month, depending on how you drive. On E-9B, you would pay $22.29 for the energy in the Summer months, $25.88 in Winter, and a little more for monthly meter fees, etc. The same usage on EV-B would be $42.00 in the Summer months, $43.23 in the Winter.

Summer on EV-B is only 3.65 cents/mile, which is over 109MPG on $4/gal gas. So, still less than half of "just drive the Prius" costs and that's with our relatively inefficient RAV4 EV. This makes the transition to Schedule EV look bad, but I've cherry picked the most favorable usage level on E-9B. Each incremental mile on E-9B over 430kWh/month (1,150mi/mo) is 9.7cents/mile. According to PG&E, this very low pricing through 130% of baseline is why they want to do away with E-9B. For customers that do not have a dedicated meter, it makes a lot less difference because with EV charging, they're up in Tier 3 and 4 anyway.

 

[cossie1600]

Not good, the house comes with 125A. I will see if I can upgrade to 200a. They said with 125a, it would still have 40A available as the house has gas stove and hot water.

 

[ekcanzano]

After upgrading from a 125A panel to a 200A panel I learned something I wish I had known when I upgraded.

I upgraded before I installed solar and before I had an EV. I knew I was going to get both. I ended up getting the solar before I got the EV and here is what I learned. Because I wanted the largest solar installation that SCE would allow, I ended up needing to downsize my main breaker from a 200A main to a 175A main breaker.

My solar installer (the greatest ever!) explained I should have ordered a 225A panel with a 200A main breaker installed. This has to do with the solar energy being fed opposite of where the utility power comes in to the panel (NEC code requirement in Article 690). My solar feeds into the panel thru a 60A breaker.

If it is not too late late, check with a really good electrician or solar installer electrician (or electrical engineer) to check out what I am saying.

Even though I wish I had know this because I would have done it, I have had NO problems with my 175A main circuit breaker tripping. But I would prefer to have the extra "headroom" given the choice. I wish I had known this before I upgraded. The cost would have been minimal.

Best of luck to you!

 

[cossie1600]

yeah i will talk the builder, house comes with a 2.1kw solar system, gas hot water and stove and dryer. So they figure 125A is good enough, but I prefer the extra margin so I don't have to load balance it. I figure doing it while the house is new is going to cost less than 1k

 

[srl99]

If your home was served by a Public Benefit Utility you would have reasonable rates (ex: Silicon Valley Power 10c/kWH all day all night all year) its the CPUC in alliance w Investor Owned Utilities (IOU) that soak the rate payers. Make sure your politicians know you are furious.

 

[cossie1600]

I am not sure what they will put in for me, but paid the stupid $1300 option. Hopefully they will at least upgrade the panel, else i don't know if they will be able to get me a 40amp breaker. The stock configuration is 100A panel, I will have a small solar panel system, gas grill and dryer. not sure if they will load like 200a of breaker on it

 

[jscgvnc]

I am not sure what they will put in for me, but paid the stupid $1300 option. Hopefully they will at least upgrade the panel, else i don't know if they will be able to get me a 40amp breaker. The stock configuration is 100A panel, I will have a small solar panel system, gas grill and dryer. not sure if they will load like 200a of breaker on it

I have an older(read 1940's) house that only has 100A service to the house. I have a Leviton 40A model, so it's fed by a 50A breaker(40x1.25 for continuous load). It's fine. The car only charges at night, after 11PM, and I've never had a problem. We also have an electric stove(also 50A), electric water heater, etc.

Electrical code says nothing about how much load(in terms of breakers) you can have in your panel. There are guidelines that electricians use about this kind of thing, but inspection and code-wise, there is nothing, unless it's specific to your authority having jurisdiction.

It does have a whole section on electric vehicles. One of the requirements is the continuous duty rating(so wire and over-current devices must use the 125% rule), and there needs to be a lockable disconnect switch(also called a safety switch) within 6 feet(might be off on the distance, I don't have the book in front of me).

Speaking of the book, I heartily recommend anyone who is interested in this kind of thing buy the NFPA NEC code Handbook. Trying to read raw electrical code is almost impossible, and this is the book where the experts explain the code with pictures and helpful examples.
It's currently $165 from the NFPA Catalog, but IMHO, it's worth it. Knowledge is power.

You could get buy some other books at the hardware store or elsewhere that would probably be fine, and wouldn't have a bunch of stuff in it that doesn't apply to you(commercial and industrial stuff, for example), but if you get into a dispute with an inspector, you can whip out your NFPA NEC Handbook and see what the real deal is.

 

[cossie1600]

I just hope htey put a 40A breaker on it, not a 30A as that would mean 6kw charging instead of 10