I am getting 228V to 231V on a 32 amp charge. The gen 3 wall connector is connected to a 240 V dedicated line with a 40 amp breaker. The gen 3 wall connector is also right beside the electrical panel so the line is very short. The gen 3 wall connector is brand new and I have only charged my car once with it. I was expecting to see 239V on my app but had seen it constantly move between 228V to 231V instead. Below is a photo. Is this normal or my charger might have some issues? Thanks!
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is charging at 228V normal?
- Thread starter kwh88
- Start date
I cannot answer your question directly but I can provide my personal experience. If I charge my car at night I can see 239V at a 48A load. If I charge my car in peak periods (morning, evening) I can sometimes see as low as 229V or something like that. The voltage drop doesn't only depend on my charger connection but also from other devices in my house and other consumption in my area. e.g. you are not necessarily provided a clean 240V 24/7...
Thanks. Do you see 229 V a lot of time? As this wall connector is new, I only charged once so far. I was charging between 5:30 pm to around 11:30 pm. At 5:30pm to 10pm, I was constantly getting 230V but dropped as low as 228V. After 10 pm, I have seen the voltage went to about 231 to 234V. However, I have never seen anything above 234V.
When you charge at peak (evening), what is the average Voltage that you are getting? I am getting about 230V. Thanks!
I'm just saying the voltage drop is relative to what gets in your house and that can change over time. I'm not monitoring that constantly, I just remember seeing those differences when looking at TeslaFi data. I almost always charge when I arrive home (thus at peak times) and don't worry about it. Here's one example from yesterday:
I had an average of 229V. I don't charge much at night so it would be tough to find the perfect example. I did charge on a sunday morning last month :
You can see this one averages 235V and peaked at 241V. It will vary...
I had an average of 229V. I don't charge much at night so it would be tough to find the perfect example. I did charge on a sunday morning last month :
You can see this one averages 235V and peaked at 241V. It will vary...
Eric33432
Member
What is the voltage immediately after the connector is first plugged into the car, but the amps have not gone to the max?
If the voltage starts out at ~240 and goes down to 228, that is likely voltage drop on the home's electrical system. If it starts out at ~ 228 or close that just means the voltage in your area is lower than the normal 240 volts, but is still within spec.
At my house, the voltage drops 3-4 volts, usually from about 240 to 237 or 236 volts when my wall connector hits 48 amps.
I visited a friend who lived in a rural area and I noticed that the voltage dropped from ~ 235 to 240 volts down to ~ 222 to 228 volts when my mobile connector hit 32 amps. And this was when it was connected to a NEMA 6-50 receptacle that had only 3-4 feet of #6 CU wire between the main electrical panel and the receptacle. I presumed the voltage drop was on the fairly long service drop feeding his house from the transformer, which looked to be pretty thin AL triplex service drop wire, probably #2 for the whole house.
The car will charge on voltages of 208 commercial service or 240 volt residential service, plus or minus at least 10% so it won't damage the car.
I would say any voltage drop is 99.9% NOT due to a defect in the Tesla Wall Connector. If you have any doubts, check to be sure the connections at the circuit breaker and the wall connector are torqued to the correct specifications.
See this for more information:
If the voltage starts out at ~240 and goes down to 228, that is likely voltage drop on the home's electrical system. If it starts out at ~ 228 or close that just means the voltage in your area is lower than the normal 240 volts, but is still within spec.
At my house, the voltage drops 3-4 volts, usually from about 240 to 237 or 236 volts when my wall connector hits 48 amps.
I visited a friend who lived in a rural area and I noticed that the voltage dropped from ~ 235 to 240 volts down to ~ 222 to 228 volts when my mobile connector hit 32 amps. And this was when it was connected to a NEMA 6-50 receptacle that had only 3-4 feet of #6 CU wire between the main electrical panel and the receptacle. I presumed the voltage drop was on the fairly long service drop feeding his house from the transformer, which looked to be pretty thin AL triplex service drop wire, probably #2 for the whole house.
The car will charge on voltages of 208 commercial service or 240 volt residential service, plus or minus at least 10% so it won't damage the car.
I would say any voltage drop is 99.9% NOT due to a defect in the Tesla Wall Connector. If you have any doubts, check to be sure the connections at the circuit breaker and the wall connector are torqued to the correct specifications.
See this for more information:
Acceptable Voltage Ranges
Voltage Relationships Based on Voltage Ranges in ANSI C84.1-2016
www.spgsamerica.com
Last edited:
ATPMSD
Active Member
Typical voltage drop figures are 2% for the branch circuits plus 1% to 2% for feeders. Note also:
“The National Electrical Code says that a voltage drop of 5% at the furthest receptacle in a branch wiring circuit is passable for normal efficiency.”
246V open circuit at the transformer is generally what utilities aim for, but in rural areas it's not uncommon to see 220V during peak demand. A multimeter is a good tool to have, so might be worth picking one up just to see what's normal for your house. A good place to test is kitchen counter outlets, as the top and bottom outlet are split and you can get your full '240V' testing from hot to hot, as well as seeing what the hot to neutral of each leg is.
Eric33432
Member
Is that top and bottom being split on kitchen outlets a Canadian thing? Never saw that in the US for kitchen circuits!
Your house likely shares a utility transformer with several others. Voltage will fluctuate depending on the load on that transformer. 228 volts isn't abnormal - I routinely see mid to high 220s in the winter when my neighbors are running heat (electric).
Your voltage drop could also be a result of the loads within your home. If you have a lot of things running, your voltage will be lower than if you have nothing else running.
Your voltage drop could also be a result of the loads within your home. If you have a lot of things running, your voltage will be lower than if you have nothing else running.
It is very common for American kitchen outlets for disposer and dishwasher to be common trip 120V, which means that the hots are 240V apart.
Eric33432
Member
Right, but never saw the individual outlets top and bottom split like that on a kitchen outlet.
That is true. The only time I have seen two sockets on one duplex outlet do something different is when a bedroom outlet has one socket always hot and the other is switched. I have never seen a kitchen outlet split for any reason and usually one countertop area with multiple duplex outlets is fed by a single 20A circuit. It is not even common to have dedicated circuits for kitchen duplex outlets, much less a separate circuit for each socket.
MLXXXp
Member
It's common in Canada. My kitchen has three split outlets., each on it's own 15A 2 pole 240V (120V per side) breaker, with 3 conductor (2 hot, a neutral, plus ground) 14 gauge wire. A newer alternative, which could be more common now, is to install a single pole 20A breaker and receptacle with 12 gauge wire, for kitchen outlets.
Voltage drop to 228V is reasonable, but keep an eye on it.
IIRC the Tesla will start reducing it's own onboard charger draw once voltage drops to 220V, but don't quote me on that. No idea how they detect / determine that that's it's not 1 phase of 3 in commercial service at 208V though...
IIRC the Tesla will start reducing it's own onboard charger draw once voltage drops to 220V, but don't quote me on that. No idea how they detect / determine that that's it's not 1 phase of 3 in commercial service at 208V though...
The NEC has required a minimum of two kitchen 'small appliance' circuits for donkeys years, although the early revisions were pretty lax on what was considered part of the kitchen. Current code is two 20A dedicated circuits solely for countertop appliances.
davewill
Active Member
My understanding is that the algorithm is much more sophisticated than simply looking for a voltage drop of a specific amount. It is looking at how that voltage changes vs amperage and time. The details are honestly beyond me.
Certainly it doesn't lower the amperage at work where the voltage typically starts at 203 and drops to 190 as the amps ramp up which is very common with long runs at commercial sites.
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