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Weak power at new place

Discussion in 'New England' started by cinergi, Dec 29, 2013.

  1. cinergi

    cinergi Active Member

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    Hi all! Wanted to get a little advice from the locals here -- and I know Mitch you've got experience with this so I'm hoping you'll chime in :)

    At my new place in Arlington, MA (electricity provided by NSTAR), I'm getting maybe 229-232V idle and 215-222 under 40A load (brand new 6 gauge temporary run I installed) I'm upping to 200A service next weekend and will be pulling 80A and I'm pretty sure that's going to cause some problems, perhaps even blow the transformer. I called NSTAR to complain and warn them about my upcoming load a couple weeks ago and they said they'd check and made an explicit note to call me. I haven't heard back. I'll call again tomorrow but wanted to know if there's a better way. I'm just calling the main number and going thru the menu until I find a human.

    Suggestions?
     
  2. mitch672

    mitch672 Active Member

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    Yep, I've gone through it, but with "National Grid".
    Tell them you are going to connect a 20KvA continuos load for EV charging, that should get their attention.
    Ultimately, they will send a lineman over to measure your service under load, when you turn on the charging, he's going to let out a bit of noise :) most likely, they'll have to get you your own transformer, I hope you have overhead service, much easier that way.

    Also, they wouldn't do much until my 200A service was officially signed off by the towns electrical inspector and they had notification, FYI.
     
  3. santana338

    santana338 Member

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    PSNH handles my service in NH. I called them and told them my voltage was getting down to 222V when charging at 40A. They came out and put a data recorder behind my meter. They confirmed the low voltage, but their real issue was the flicker noise violated a GE spec. So they upsized my transformer and the line to the house. It's all good now. Nots ure how this will apply to you with NSTAR, but since you have notified them the ball is in their court. You just might not want to charge at full power until they get back to you.
     
  4. Lloyd

    Lloyd Active Member

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    #4 Lloyd, Dec 29, 2013
    Last edited: Dec 29, 2013
    I tried to be proactive with PG&E in California. I came to the conclusion that they would rather replace a blown transformer and infrastructure and respond to a customer warning them of an issue. Earlier I reported a high voltage issue, and they responded promptly and found a Co-Gen plant putting spikes in the system which they required the generator to fix.

    There are software electrical monitoring systems that can log some impressive data to show your power company. American Power Conversion (APC) makes 'Power Chute' . Years ago I showed that we had a 10% + drop in voltage at my office every day at 9:00 am exactly causing the UPS's to all trip. Showing them the weeks/months of data helped them locate the issue and fix it.
     
  5. mknox

    mknox Well-Known Member

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    In Canada, the CSA defines "Preferred Voltage Levels for AC Systems" and includes "Normal" and "Extreme" conditions. These voltages are measured at the service entrance, not the utilization point in the building. When voltages fall out of the "Normal" range, but are not yet in the "Extreme" range, utilities will schedule repairs (usually a transformer tap change) on a non-emergency basis. When voltages fall into the "Extreme" range, utilities will prioritize repairs. I would imagine the US code has something similar. Here is the table:

    Voltages.jpg
     
  6. montgom626

    montgom626 Active Member

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    Very nice chart. Good info.
     
  7. cinergi

    cinergi Active Member

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    I called again -- it's not like the people that I initially get a hold of understand the technical details but I said I'm concerned I'm going to blow the transformer and take out the neighborhood blah blah blah ... and that under 1/2 load I'm measuring 215v. The real issue is they supposedly sent someone and repaired something (nothing has changed) but I never got a phone call. So I emphasized, and she emphasized on the work order, that I need a phone call to describe what I'll be doing and what I'm seeing. She couldn't give me an ETA on a return call. I may end up having to take out the neighborhood :-( I'll wait until I have a generator first heh.
    Power lines are overhead. I keep forgetting to locate the transformer, though thus far I haven't seen any pole-mounted ones. Not sure where they are yet, so no idea how big they are or how many people they serve. The power to the house is relatively crummy -- I can see changes in the voltage via the lights quite frequently. So far the Model S hasn't cared about that though, thankfully.
     
  8. mknox

    mknox Well-Known Member

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    The utility is responsible for voltage levels at the service entrance, not the utilization point as there could be voltage drop within the building wiring. If possible, you should try to measure at your panel under no load and load conditions. 215 volts would be considered just outside of normal operating conditions on a 240 volt circuit. I suspect you're probably a volt or two higher at the demarcation (panel) point. There's really no way to tell if you have an undersized transformer, undersized lines or some combination. Everything may in fact be adequate but since you mentioned not being able to find the transformer, the voltage dips may just be a result of line losses over a long distance.
     
  9. cinergi

    cinergi Active Member

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    Yep, I know I'll be a couple volts lower at the usage point vs. entrance point and since it's a new temporary install I just did, I'm comfortable knowing it's not a big loss from the 50A breaker to my 14-50 (I observe low voltages elsewhere in the house, too). It's possible the panel or something else I'm responsible for is at fault (read on...)
    This is only under 40A load. I'm going to dip that under 210 or worse when I put an 80A load on it. I'm having my 200A installed this weekend so I'll try to remember to measure it as close as possible to the service entrance (e.g. right before the meter) while things are opened up. The 200A upgrade may uncover and fix a customer-side problem, too -- we'll see.
     
  10. mitch672

    mitch672 Active Member

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    Ben, more important is, once you have a 200A service, if you can't draw an 80A load, the utility will have to fix their issues, in my case they upsized the conductors and installed a dedicated transformer. If you can't locate the transformer, they might be in underground vaults, possibly.
     
  11. cinergi

    cinergi Active Member

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    Well apparently they stopped by, pulled the meter, and checked the voltage. "perfect 240/120. Right sure maybe at 12:30pm when you tested it, and without load. And ignored my ask to call me for the second time. So guess what, you'll be coming back out here. *sigh* I'll call them AGAIN and instead of making this a "low voltage" call, tell them I'm adding 20kW continuous load.
    BTW I checked voltage at the panel inlet vs what the car is reporting -- a 2V difference.
     
  12. mknox

    mknox Well-Known Member

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    Some utilities will install a recorder for a few days or weeks to investigate power quality issues like this. Might be worth describing what you're doing (I assume you already have) and ask for a recorder to keep an eye on voltage levels for a few days under various loading scenarios. They are obligated to keep your voltage within nominal limits at your service entrance point.
     
  13. cinergi

    cinergi Active Member

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    Service upgraded. Today I started at 232 volts and dropped to: 226 @ panel / 219 @ car (80 amp draw). So, better than I feared, but -- I think I have a "right" to have at least 233 even under load, so I can now at least call nstar and tell em hey I have a brand new drop and it's still sagging too much. I found the transformer -- it's several poles down the road -- looks like it's serving quite a few homes and looks like your normal small pole transformer.

    I tried to plug the car directly into the eu6500 and no go -- it saw that it wasn't grounded. While the genny is connected to the house, that shouldn't be an issue, but I haven't tried it yet. It got really late before the main service upgrade and genny input was complete. I'll try it out tomorrow. I'm also having a problem with the generator hunting/surging under certain loads :-( so I need it serviced. Damn thing's brand new and this is the first time I've used it and it's busted. *sigh*
     
  14. mknox

    mknox Well-Known Member

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    240 volts is the "nominal" level. Normal levels (which you have a right to) are 220 to 250 volts. At least here in Canada. I suspect the US has similar min and max voltages since a lot of the regulations are harmonized. There is likely a voltage drop on the secondary mains between the transformer and your service drop. This is normal, and doesn't necessarily mean anything is undersized. I can see the voltage vary by several volts at my own house with no change in my load at all due to other customers on the street. If your utility were to bump the taps up on the transformer to compensate for the line losses to your drop, other customers close to the transformer may suffer from the opposite problem and have high voltage.
     
  15. cinergi

    cinergi Active Member

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    NEC here recommends no more than 3% loss to my panel and 5% to the plug (if I'm reading this right) -- either way my electrician said I'm "entitled" to no more than 3% loss at my panel.

    The setup here is ridiculous -- one small transformer serving probably 20 houses or more and all of them in series off relatively small aluminum wire on the pole. I see voltages from 240 to 215 here *without* load at my house. I see the lights changing output all the time (meaning, multiple times per minute). It's quite undersized here. This should be a fun conversation, if I can just get my damn message to the tech.
     
  16. mknox

    mknox Well-Known Member

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    20 is a bit much... 8-10 is more typical. A good solution would be to install another transformer closer to your house and split the number of customers on each. If it helps in your conversations, utilities in my neck of the woods consider a Model S with twin chargers the equivalent of 4 typical homes on the distribution system.
     
  17. cinergi

    cinergi Active Member

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    I talked to the town's Nstar service engineer ... apparently there's a form for the electrician to fill out for the service upgrade we did (they don't usually notify the town for various reasons), which includes a spot for the 20 kW load I'll be adding. The service engineer triple-checked me on that 20 kW number so I at least got her attention :) We'll see where this goes ....
     
  18. Park2670

    Park2670 Member

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    I wonder how many more times you will need to call to get their attention?
     
  19. qwk

    qwk Model S P2681

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    It might take a transformer fireworks show to get their attention.
     
  20. Robert.Boston

    Robert.Boston Model S VIN P01536

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    NStar has a well-deserved reputation for lousy customer service. As I shift my household up to Maine, it's been a delightful contrast working with Central Maine Power.
     

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