300-400 amp service for homes are mansions. Are you putting these services in yourself,or telling us about them?

Not your typical home by any means. Modern homes are using less power.

As far as the grid in WI is fine. You will charge at, when load is at lowest. Someone here from Michigan was saying utilities are going back to time of use rates. They give deals to industrial customers to get all the power the want at night, because demand is down

People will charge at night, when home.

Utility where I am said concern is voltage drop, so will need to replace transformers with higher impedance.

 

Places like TX and CA with poorly managed grids may have issues, especially CA that forces EV.

But again, is not all or nothing in most areas. As you are saying no EVs, so will be slow and less taxing of the grid for most areas

Utility meeting I was in compared to stove, 50 amps. People are not running stoves at night in most homes.

Utilities makes there profit off capital investment where I am at. They will be happy to upgrade . We just got done, mostly,of upgrading from 4kv. We got the resources and it won't be over night

Again, if people charge when they are home, it will be at night, when loading is way down anyways.
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I work for an electrical contractor. 20yrs. I've installed them. I don't speak without knowledge, thank you. We either install 2 - 150 amp main panels or 2 200 amp main panels. 300 and 400 amp. These aren't cookie cutter homes, but they're far from mansions. Small homes still get 200 amp. I don't think we've installed a 100 amp service in over ten years.

Homes today all have heat pumps or AC (a lot of times zoned with multiple units), microwave, refrigerator (most times 2), counter top ice makers (for the good ice), deep freezer, dishwasher, washer, dryer, TV in every room, heated bathroom floors, massive water heaters (unless gas is available), etc. They are more efficient, but packed with more electric devices than ever. People want all the convenience features. They load them up with tons of lighting, inside and out. LED lights are efficient, but if you install 120 - 8 watt fixtures, compared to the days of 1 - double 60 watt fixture per room, you're not saving much.

The utility would have to put bigger transformers in to handle the larger demand that is causing the voltage drop. Thusly, our infrastructure can't handle the demand. They're not ready for EVs.

This past year there was a transformer shortage. It was global. My friend, who's a lineman for a large utility, said that they were expecting an order of 20,000 pole mount transformers. They, as a company received 6. They were sending line trucks to look at abandoned properties. If the power was disconnected and service in ill repair, they would take the pole mount transformers to use where they had failures, or to complete services that were ordered months prior. My project (a $26 million Non-ferrous recovery facility) was delayed by 3 months because they couldn't provide the pad mount transformer. They are FAR from being ready to upgrade everything for the EV market.

 

I fixed it for you, man…

 

I work in the power sector. The utility said to offset voltage drop, they will install transformer with higher impedance.

Transformers at the station have tap changer on the low side the transformer. They some times will also put voltage regulators on the lines. By changing impedance at the home it will also raise voltage at end user.

As I have said load is way down at night.. this is when homes will be charging.

I put the stuff in and trouble shoot for a living. I started out as residential electrician.

I know homes that still have 60 amp service.i have 100 with air handler, well, dryer. With LEDs and new appliances load has gone done. People are not running every Gizmo at once. You should know how to derate and coincidental loads too

I used to size services for consultants, long ago. It's all about the tricks to get a smaller service. A good master electrician can do that. Myself I just did basic.

300-400 amp service in residential homes is not normal homes. 200 amps is more for added branch circuits than load, I suspect. We use lots of circuits these days .

If you want to learn about utility world, let me know.

I've been doing this 30 years, in one form or another

 

I put in 80 mva transformers,pad mounts are just drop in for small stuff

Yes there is shortage, but we yards full of them. This isn't happening over night

 

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I have to say, that's the most well articulated response I have ever seen you type on this forum. I'm glad to see you actually know something about something. Good for you.

2000 amp 480v 3 phase service coming off that pad mount transformer. Not talking residential single split phase.

 

Usually you go up in voltage to decrease amps. 2000 amp service? How big are the lugs on the service?

I do 2000 amp bus and breakers, but a lot higher voltage. Parallel 500s or copper bus. I am not familiar with service that big. I would think multiple services. But I don't work with low voltage, so I can't say for sure.

But back your earlier claim you think they will need bigger transformers. Load changes all day. They do not change the transformer out every 15 minutes. The change taps on the transformer to maintain voltage where they want it.

Read up on beckwith controls and reinhaussen tap changers.

You change tap ratios, to raise and lower voltage.

 

I understand how taps on transformers work. I will concede that I thought you were initially saying that they would need to change the transformers for impedance. I misunderstood what you were saying, because frankly not many people understand what impedance means. Or how transformers and taps work. Yes you are correct, re-tap and boost the voltage up. No transformer change needed until demand gets high enough.

There are a lot of areas in this country that still run on lower transmission voltages. If they need to increase those voltages to accommodate demand, there will have to be some hardware changes. We wired a marijuana grow operation in a part of town that used to have a lot of industry (potteries). The initial plan was, because the utility couldn't provide enough power, the facility would have to co-generate (with generators) the extra power they would need above what the utility could give them. We have a good relationship with our local utility planner. They decided to increase the voltage on the entire street to meet the supply request of the marijuana operation. They replaced all the secondary cans on the poles all the way through town. They couldn't support a building full of light bulbs, how can they support the EV demand if there's one in every garage in town?

Regarding my previously mentioned project
1. Utilities don't give you multiple services of the same voltage on a commercial or industrial building/property typically.
2. You can't up the voltage to decrease amperage. The building and all the machinery inside need 480vac. So we size the service accordingly, or whatever the engineer specs, typically. We step down after the main for a 120/208 volt panel. It's usually just for the outlets and office equipment. Maybe door openers. Small stuff.
3. The main switch gear is spec'd with lugs to accommodate our parallel conductors. Lands straight into the main breaker.

Side note: Same company has a 1000 amp 4160vac service to feed a 2500HP shredder motor. We control it with a liquid rheostat. When we replaced their underground feeders, the line crew was surprised that they had that much ampacity @4160vac going into the facility. We step down to 480vac 1200 amps inside the building. That runs all the conveyors, vibes, dust collection, water injection, Eddy Current, etc. The facility owns that big air cooler dry transformer. It's massive and expensive. The only thing that needs 4160 is the main motor.

Pad mount



Landing the main breaker