Pro Charger Just connected and not hitting 19KW

[bmwhitetx]

And I think I found why I'm not even getting 17.6kW anymore. When I installed my FCSP, I was reading around 238.5V on my service. I'm now reading 233.5V. And it drops to 223V when the FCSP is actively charging set to 80A. I think the transformer at the road is getting worn out.

I’m guessing this was tongue in cheek . Transformers don’t slowly wear out voltage ratio-wise. They will go out with a bang though. Worked for a utility for 35 years. There are many reasons your voltage will vary over time. New loads, feeder/ branch circuit changes, adding/ removing line capacitors, you and neighbor’s loads, etc. Oh and a heat wave and resulting AC load can impact it as well. Can your Emporia monitor graph over time?

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[Pioneer74]

I’m guessing this was tongue in cheek . Transformers don’t slowly wear out voltage ratio-wise. They will go out with a bang though. Worked for a utility for 35 years. There are many reasons your voltage will vary over time. New loads, feeder/ branch circuit changes, adding/ removing line capacitors, you and neighbor’s loads, etc. Oh and a heat wave and resulting AC load can impact it as well. Can your Emporia monitor graph over time?

I don't deal with transformers very often, but doesn't voltage change when the varnish between the windings starts to break down?

It can monitor over time, but I constantly adjust the amperage the FCSP puts out. So there isn't any data I could pull up that would be useful.

 

[TaxmanHog]

I don't deal with transformers very often, but doesn't voltage change when the varnish between the windings starts to break down?

Typically leading to this:

 

[bmwhitetx]

I don't deal with transformers very often, but doesn't voltage change when the varnish between the windings starts to break down?

Yeah, transformers can go bad with winding shorts. Your voltage drops pretty dramatically with the added load, that wouldn’t be a winding issue primarily but under-sized conductors or transformer. Utilities strive to maintain 240 +/- 5% at the meter. So anything below 228V at the meter is an under voltage condition. You could ask the local utility to come check it out. They should do that for free. But they will only check up to their point of delivery which is typically the meter. Next time also check the two legs, line to neutral to see if reasonably balanced. If not, that may point to a conductor/connector/xfmr issue on that leg.

 

[Calvin H-C]

You could ask the local utility to come check it out. They should do that for free. But they will only check up to their point of delivery which is typically the meter.

If you have a smart meter, they can probably check this without even coming out to your home. If you have the option for time-of-use billing, then you have a smart meter.

A few years back, the connector for one of our lines burnt off (probably wasn't properly installed originally) and left us with half the house without power.

When it happened, I checked our main panel and found one leg dead with the other still provided 120 volts. None of our neighbours on the same transformer had this problem.

When I called the utility, they had to ask my permission to go into our meter to read it remotely. When they did, it confirmed 120 volts on one leg and 0 volts on the other. They sent out a crew and it was quickly fixed.

I got to see the old connector - it was in bad shape, melted and all.

When I installed my FCSP, I was reading around 238.5V on my service. I'm now reading 233.5V. And it drops to 223V when the FCSP is actively charging set to 80A. I think the transformer at the road is getting worn out.

Just a thought - perhaps there may be a connector issue like I had. Your voltage drop could be occurring at a not-very-good connection. It would increase when your load increases. That extra 10 volts with 80 additional amps represents 800 watts extra, which might make for a pretty hot connector. Though, some of that drop is likely due to other things like the wiring, so any power it has to dissipate is spread over a greater area and may only be warming a long length of cable by 5-10 degrees.

 

[Maquis]

Yeah, transformers can go bad with winding shorts. Your voltage drops pretty dramatically with the added load, that wouldn’t be a winding issue primarily but under-sized conductors or transformer. Utilities strive to maintain 240 +/- 5% at the meter. So anything below 228V at the meter is an under voltage condition. You could ask the local utility to come check it out. They should do that for free. But they will only check up to their point of delivery which is typically the meter. Next time also check the two legs, line to neutral to see if reasonably balanced. If not, that may point to a conductor/connector/xfmr issue on that leg.

In my experience, a transformer doesn’t last long once a winding shorts. The localized heat buildup leads to catastrophic failure pretty quickly. I’d bet that the low voltage being seen is most likely due to increased loading by the homes connected to that transformer.
I second your comments about voltage tolerances and having it checked by the utility.

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