Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

We've been getting high voltage from the grid (AC1) ever since we installed our system. Everyday we get an F31 fault for over voltage. Through some observations I found the following:
-Voltage typically went over 130V around midday and stays around 122-124V at night.
- Our house is just outside a coast guard base which recently installed a solar system with panels in every single structure in the base (over 1,000 panels)
- If clouds appear in the area voltage will go down, sometimes as much as 7V. If the clouds go away (during midday) voltage will once again increase.


From these findings I concluded that the coast guard's system is so big (remember over 1,000 panels) that it is increasing the voltage on the grid causing our inverter to disconnect everyday around midday (safety regulation?). I have spoken to the power company and our contractor, neither one was aware of the problem. The power company verified the voltage is too high in parts of the neighborhood and is currently working to fix the issue, but we do not expect them to do so anytime soon since the fix requires major changes to the grid.

The XW6048 requires the voltage coming from the grid to be below 130.5V or so. If it goes above that the inverter will stop selling and give a fault. The odd part about the setting is that after the fault, the voltage must stay below 126V (not 130V) for 5 minutes before selling again. As a result our inverter has at times stopped selling at 10am and won't sell again until after 5:30pm.

The contractor claims that the maximum AC1 voltage cannot be easily changed on the inverter. Is the contractor correct? What about the AC1 Hi Volt option in AC settings (page 3-19 of Manual)?

Any help will be much appreciated.

Comments

  • BB.BB. admin Super Moderators, Administrators Posts: 29,634 admin
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    I don't know--But many GT inverter systems include a "service" (password protected/special software) menu where they can "tweak" things like high/low voltage and frequency limits with approval of the utility.

    Usually, it is not a big deal (as I understand) to adjust a pole/distribution transformer to move the "grid voltage" up or down a bit to bring the neighborhood into voltage compliance. But if a large/distributed GT Solar installation is exceeding their system design capacity (voltage drop/voltage rise)--Yes it is a big deal for the utility.

    There have been reports of a least one new home community that was not allowed to offer GT solar on their new homes unless they paid a lot of money to utility to upgrade their local distribution system. It should be possible to get the PUC to "turn off" the offending large GT system if it is taking the utility power out of regulation.

    But--you now are seeing the "down side" of distributed power generation and the lack of support that a utility feels they have to provide for something regulators make them support (GT solar and Net Metering).

    You may have to go to the state PUC if you feel the utility is giving you the run-a-round.

    Interestingly, when I used to design computer systems, there was not a "national" min/max limit for frequency and voltage that utilities had to guarantee to their customers...

    In the end, I decided that 240 VAC (120 VAC) was from 106/212 VAC to 132/264 VAC (roughly +/-10%) (although, since I designed for Japan, I had to go down to 95 VAC because parts of the country had 100 volt mains).

    From Wiki:
    Following voltage harmonization, electricity supplies within the European Union are now nominally 230 V ± 6% at 50 Hz.[1] For a transition period (1995–2008), countries that had previously used 220 V changed to a narrower asymmetric tolerance range of 230 V +6% −10% and those (like the UK) that had previously used 240 V changed to 230 V +10% −6%.[2] No change in voltage is required by either system as both 220 V and 240 V fall within the lower 230 V tolerance bands (230 V ±6%). In practice, this allows countries to continue to supply the same voltage (220 or 240 V), at least until existing supply transformers are replaced. Equipment used in these countries is designed to accept any voltage within the specified range.


    In the United States[3] and Canada,[4] national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 to 126 V ( RMS) (−5% to +5%). Historically 110, 115 and 117 volts have been used at different times and places in North America. Main power is sometimes spoken of as 110; however, 120 is the nominal voltage.

    In 2000, Australia converted to 230 V as the nominal standard with a tolerance of +10% −6%.,[5] this superseding the old 240 V standard, AS2926-1987.[6] As in the UK, 240 V is within the allowable limits and "240 volt" is a synonym for mains in Australian and British English.

    See if you can get the utility to put in writing what your allowable voltage range is--It sounds like the already agree there are problems, and so far have not pointed at you for being a contributor to the grid voltage problem.

    We had somebody here with an Enphase (micro) GT Inverter system were the "factory" came out and reprogrammed the upper limit up a couple of volts (as I recall) on the local GT inverters.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bakuninbakunin Registered Users Posts: 4
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    Thanks for your reply Bill,
    Yes, it appears there is a software to tweak settings, but it is not easy to obtain. At the moment a friend of a friend is trying to get his hands on one. A power company official himself suggested we change the settings in the inverter. To try to pressure the power company to deal with the situation I have contacted community leaders and the coast guard. I believed the coast guard would at least have some panels that are not selling and that turned out to be the case. Hopefully with the community and coast guard pressure the power company (which is run by the government here in Puerto Rico) will do something about it 'as quickly as possible'. Funny that you mentioned that the power company has "not pointed at you for being a contributor to the grid voltage problem". They actually did, and our incentive application was momentarily in jeopardy. It was explained to them that my 2.8Kw system would not cause any significant changes on the grid's voltage and that they had now basis to reject our application. I think they realized we were willing to take them to court and backed off :)

    Currently we are fine tuning the use of the load shaving capability at night to try to make up for some of the power we were not able to sell in the past. Once again thanks for your help,
    Robert
  • Ralph DayRalph Day ✭✭✭✭ Solar Expert Posts: 887 ✭✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    "We had somebody here with an Enphase (micro) GT Inverter system were the "factory" came out and reprogrammed the upper limit up a couple of volts (as I recall) on the local GT inverters."

    Me.

    Enphase reprogrammed all the 52 inverters remotely to the upper voltage limit of 260vac. It didn't take long, but needed the high speed internet connection to the Envoy unit. Anyone worried about security...I shut off my computer during the upgrade, the internet>envoy connection did not include my computer. Enphase is always in contact through my hs connection, the laptop is put in sleep or hibernate when not in use.

    Ralph
  • solar_davesolar_dave ✭✭✭✭ Solar Expert Posts: 2,344 ✭✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    I don't get the stress of opening the Envoy up via a port forwarding setup in the router. I expose my TED to the Internet this way. No other hosts inside are exposed and only the TED appliance on a particular port is visible.
  • bakuninbakunin Registered Users Posts: 4
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    Contractor claims he is awaiting for the software to change upper limits. He mentioned something about us being able to monitor the inverter online but made it sound like the capability is not available yet.

    I've been looking into the advanced settings and I was wondering if changing the AC1 Hi Volt setting at advanced settings-AC settings (see page 3-19 of inverter manual) would help. The default is 132V. It appears the contractor increased it to 135V and I just bumped it up to 140V
  • boBboB ✭✭✭✭ Solar Expert Posts: 965 ✭✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    Aren't you kinda worried about breaking things with too high of AC line voltage ??

    132VAC is high enough but 140 VAC ??

    boB
  • bakuninbakunin Registered Users Posts: 4
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    Yes, certainly damaging the electronic appliances is a concern. But there's certain points I left out of the story for the sake of simplicity. For one, we discovered the high voltage issue in April and only now the power utility is claiming "it will deal with it". Another interesting point is that high voltage IS NOT the only problem we are experiencing with the power company. Since January or so, about once a month we have been experiencing "brown outs". These brown outs will sometimes last for hours (although recently they don't last long). The power company is not sure why the brown outs occur. We suspect that they may be related to the coast guard solar system but thanks in part to how infrequent the brown outs are, it is hard to know (or fix) what's going on. During brown outs our voltage is all over the place and I've measured it around 80V. The voltage changes are sometimes so drastic that batteries momentarily crash and our fridge's icemaker starts making popping sounds. In short, we figured, the voltage issues with the power company are already having an effect on our appliances. Oh well, I guess that's the price to live in paradise :)
    Anyway, I did increase the upper limit to 140V and the inverter still disconnected today (although I have never seen the AC1 go over 132V on the monitor). On the first chapter of the Xantrex inverter manual it clearly says that anti-islanding settings can be changed if needed. I sent an email to them requesting assistance. They have not answered yet.
  • nielniel ✭✭✭✭ Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    the utility is responsible to keep the voltage within set limits or they can be held liable for damages. in my area 127vac is the max allowed or 254vac across the so called 240vac wires. the problem with higher voltages is that often higher currents go along with them and you have a 2 fold dilemma facing everything connected to the grid. this higher power is extra heat and will decay the lifespan of items connected to it if they aren't immediately destroyed by the higher voltages. what's worse is the extra power being dissipated you will get billed for so this is insult to injury.

    if this were to continue on without resolution then, in addition to a lawsuit, i would be making active efforts to go off of the grid.
  • inetdoginetdog ✭✭✭✭ Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?
    bakunin wrote: »
    Since January or so, about once a month we have been experiencing "brown outs". These brown outs will sometimes last for hours (although recently they don't last long). The power company is not sure why the brown outs occur. We suspect that they may be related to the coast guard solar system but thanks in part to how infrequent the brown outs are, it is hard to know (or fix) what's going on. During brown outs our voltage is all over the place and I've measured it around 80V. The voltage changes are sometimes so drastic that batteries momentarily crash and our fridge's icemaker starts making popping sounds. In short, we figured, the voltage issues with the power company are already having an effect on our appliances. Oh well, I guess that's the price to live in paradise :)

    One predictable effect of the coast guard system is that the load on the utility grid (ranging between positive and negative) can vary drastically and rapidly as clouds pass over the base. If the same amount of power came from a lot of small systems distributed over a large area, the effect would not be as drastic. Possibly the voltage fluctuations which result are causing some other loads somewhere else, such as large motors, to go into a condition in which they are drawing very high current at lower voltages and dragging the grid down until their overcurrent protection shuts them off. Then they try to start again. Or it may be totally unrelated to the base's solar system at all. If it is the explanation and the site which is dragging the system down does not complain, it may be very hard to track down the problem.
    You can do your own experiment by measuring the voltage you see on a day with scattered large clouds passing over the base.
    SMA SB 3000, old BP panels.
  • BB.BB. admin Super Moderators, Administrators Posts: 29,634 admin
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    Also note if the problem is limited to your pole transformer or system wide in the area (i.e., guy next do with a machine-shop in his garage) vs something "big" that is affect the entire area (should like it is not local to your pole transformer).

    And if it is system wide--they do have a difficult bit of debugging/failure analysis ahead of them. Which you will probably need to keep on their back to ensure it does not get dropped.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jeffkrusejeffkruse ✭✭✭ Solar Expert Posts: 205 ✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    Welcome to Puerto Rico wear we pay so much more for power and get terrible service. I now live in Moca and have been back on the grid for 6 months now. The power is terrible. I can’t speak about the surges but the “brown” out are bad. Many many times I have measured voltage less than 80 for hours. 40V for 3 hours on one leg. Some electronic devices were trying to work. Then, not only is the voltage low for so long it turns on and off real quick!!!

    I have surge protectors on everything but that doesn’t help during brown outs. I did a search online and found some info on devices that protect against low voltage (they shut off and have hysteresis) but they don’t manufacture the devices! Hello, sounds like an opportunity. If someone knows of something that protects against brown outs please let me know!

    My friend in San German who installed a 3600W grid tied system had trouble for a year due to high voltage. Same issues as you but it was a Hospital next door that PREPA blamed it on. PREPA finally fixed it but then my friend had to fight with them every month on the billing. It took another year to get that straightened out.

    Keep on PREPA, it may take them a year but they will fix it. Niel, this is Puerto Rico and worse yet this is the power company. It’s been documented that their own workers sabotage equipment. On top of that so many bills go unpaid and the power company is powerless to collect. It’s a sport here to cheat the power company. The people here brag about it. The last owner of my former house told me how his meter was hooked up wrong by the power company and for 2 years he was only billed for half of the power he used. Just be glad we are not talking about the water company! They are much worse!

    Mods, feel free to edit or delete if inappropriate.
  • inetdoginetdog ✭✭✭✭ Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?
    jeffkruse wrote: »
    I did a search online and found some info on devices that protect against low voltage (they shut off and have hysteresis) but they don’t manufacture the devices! Hello, sounds like an opportunity. If someone knows of something that protects against brown outs please let me know!

    It may be a little beyond your comfort price range, but undervoltage protection is standard in many motor starters. They contain a voltage sensor which will open the contactor (relay) when the voltage on any phase goes below the set limit. They may require manual reset once the voltage goes back up though.

    The other approach is a tap-changing voltage boost autotransformer, but this has a limited correction range and makes the problem worse for everybody else by taking more current to compensate for the reduced voltage.
    SMA SB 3000, old BP panels.
  • nsaspooknsaspook ✭✭✭ Solar Expert Posts: 396 ✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?

    Another way (possibly cheaper) to reduce voltage without the cost of a large auto-transformer is to use a bucking transformer circuit that can be switched in or out.
    http://www.hammondpowersolutions.com/products/locate_by_product/buckboost_transformers/index.php
    The bucking transformer works by placing the secondary of a (relatively small) transformer in series with the mains, but wired out-of-phase so the voltage is "bucked" or reduced by subtraction. Only the secondary winding needs to carry the full mains current. This means that for 240V to 220V we need to "buck" 20V at 10A - a maximum of 200VA. Likewise, for 120V to 110V, we only need to buck 10V at 20A ... also 200VA.

    http://sound.westhost.com/articles/buck-xfmr.htm
  • jaggedbenjaggedben ✭✭ Solar Expert Posts: 230 ✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?
    nsaspook wrote: »
    Another way (possibly cheaper) to reduce voltage without the cost of a large auto-transformer is to use a bucking transformer circuit that can be switched in or out.

    I would urge the original poster NOT to do this. It simply creates a greater overvoltage on the grid side of the buck-boost transformer, and exacerbates the grid overvoltage problem for the neighboring customers, especially if they also happen to have solar. And if the utility found out it they could re-open the argument as to whether the OP is contributing to the problem, as has been alluded to above.

    What is really uncool is to install this type of transformer as a way of dealing with voltage drop on an inverter output circuit that was sized too small. I realize that you are not proposing it for that exact reason, and that you are proposing that it be capable of being switched in and out. But the same reasoning still applies, especially if happens to get left switched on when the utility voltage is in range (which will be tempting if they don't solve the problems).

    Note to installers everywhere, do not use buck-boost transformers to deal with voltage problems. It's probably not legal, decreases efficiency, and puts a band-aid on the real problem instead of solving it.
  • nsaspooknsaspook ✭✭✭ Solar Expert Posts: 396 ✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?
    jaggedben wrote: »

    Note to installers everywhere, do not use buck-boost transformers to deal with voltage problems. It's probably not legal, decreases efficiency, and puts a band-aid on the real problem instead of solving it.

    N.E.C. Article 450-4, “Autotransformers 600 Volts, Nominal, or Less.”
    The NEC Article 450-4 outlines overcurrent protection for autotransformers. It is reproduced as follows:
    “NEC 450-4 - Autotransformers 600 Volts, Nominal, or Less
    (a) Overcurrent Protection. Each autotransformer 600 volts, nominal, or less shall be protected by an
    individual overcurrent device installed in series with each ungrounded input conductor. Such overcurrent device
    shall be rated or set at not more than 125 percent of the rated full load input current of the autotransformer. An
    overcurrent device shall not be installed in series with the shunt winding.
    Exception: Where the rated input current of an autotransformer is 9 amperes or more and 125 percent of
    this current does not correspond to a standard rating of a fuse or non-adjustable circuit breaker; the next higher
    standard rating described in our section shall be permitted. When the rated input current is less than 9 amperes,
    an overcurrent device rated or set at not more than 167 percent of the input current shall be permitted.
    (b) Transformer Field-Connected as an autotransformer. A transformer field-connected as autotransformers
    shall be identified for use at “elevated voltage”.

    There is nothing illegal about buck-boost transformers and it sure is a band-aid for the problem of poor regulation of voltage that's probability caused by far end power insertion from the CG station that might require a major infrastructure upgrade from the utility to solve. Unless he's selling a huge amount of power it won't change the utility feed voltage but will allow the inverter to supply power to household loads.
    If this was stateside I'd rarely suggest it but I've lived overseas on small island utilities where voltage buck/boost was a necessary evil.
  • jaggedbenjaggedben ✭✭ Solar Expert Posts: 230 ✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?
    nsaspook wrote: »
    N.E.C. Article 450-4, “Autotransformers 600 Volts, Nominal, or Less.”

    There is nothing legal about buck-boost transformers ...

    Did you mean to say nothing illegal? That seems to be what you're arguing.

    I don't know why you quoted the NEC, the reasons I said 'probably not legal' have nothing to do with the NEC, they have to do with the IEEE standards for utility voltages.
    and it sure is a band-aid for the problem of poor regulation of voltage that's probability caused by far end power insertion from the CG station that might require a major infrastructure upgrade from the utility to solve.

    Which is what they should do. Or ask the CG station to reduce its power output. Or whatever works for them, we really don't actually know what the problem is, it could be with the pole transformer. Or they could probably solve the problem with a minor upgrade there.
    Unless he's selling a huge amount of power it won't change the utility feed voltage but will allow the inverter to supply power to household loads.

    What amount of power is too much? It depends on the utility infrastructure. Let's not encourage people to make up their own rules about when its okay to export to the grid. It's the utility's responsibility to regulate voltage. Let them do it, demand that they do it. Wait for them to say that they are not going to do it and you should take measures on your solar system.
    If this was stateside I'd rarely suggest it but I've lived overseas on small island utilities where voltage buck/boost was a necessary evil.

    A fair argument at least where you only have loads and not a grid-tied inverter. In this case it would seem that re-programming the inverters voltage range would be the cheaper solution that will not contribute to any other problem down the road. That is definitely Plan A.
  • nsaspooknsaspook ✭✭✭ Solar Expert Posts: 396 ✭✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?
    jaggedben wrote: »
    Did you mean to say nothing illegal? That seems to be what you're arguing.

    (Tks) Fixed to illegal. :blush:

    The odds of the CG station cutting back power and/or the utility rushing out a fix IMO are low judging from others past experiences in PR. Chanchullo sometimes helps to get things moving.

    I mainly agree with what you are saying but adjusting the inverter voltage range is also a band-aid (a nice software one) for the out of spec utility voltage because the neighbouring customers will see the same high (illegal?) voltage pushed from his house (with or without the BB transformer) and now his equipment will see out of spec voltage also.

    http://www.powerqualityworld.com/2011/04/ansi-c84-1-voltage-ratings-60-hertz.html
  • jaggedbenjaggedben ✭✭ Solar Expert Posts: 230 ✭✭
    Re: Voltage from grid too high. Is it possible to change XW6048 maximum voltage setting?
    nsaspook wrote: »
    adjusting the inverter voltage range is also a band-aid (a nice software one) for the out of spec utility voltage because the neighbouring customers will see the same high (illegal?) voltage pushed from his house (with or without the BB transformer) and now his equipment will see out of spec voltage also.

    Fair points. The difference is that with the software fix if the utility fixes things on its side then the whole problem will go away automatically.
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