Electrician trying to help friend !

I am new to the solar thing and am in need of guidance. Here is what I know.

Les has 30-200W PV panels so thats 6K of potential from the sun.

Those 30 panels are connected to a xantrex solar charge converter.

The charge controller is connected to a 48v DC battery bank.

There is also a 48V windmill connected to the 48v DC battery bank.

The XW6048 Inverter is connected to the battery bank.

The inverters output is connected to a standalone sub-panel in the house which runs a few loads.

the primary 200a breaker panel has a 2p breaker that goes to the inverter. I would say it is a signal line due to it's small gauge and if that breaker is switched off the inverter charged panel stops stops functioning.

the 200a main panel is connected to the power co with a net metering meter.

That is what I know. They have not been selling power due to the inverter not being connected to the main panel to transmit power back thru the meter ? Correct?

I have the operator and install manuals for the XW6048 but they do not say how to connect the inverter to the main panel.

The inverter is connected to the isolated sub panel w 6ga stranded wire.

So do I simply connect the leads from the inverter to the main panel w a breaker and feed the "signal" line with another 2pole breaker?

Sincerly Confused in Pittsburgh
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Comments

  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    I know there are AC in AC Out an Gen connections on the inverter.

    I know the books say things about connections, but I need clarification on what hooks where.

    Sorry for the confusion. :-)
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Electrician trying to help friend !

    One problem I see before you even get to the inverter issues is 6000 watts of panel on a Xantrex charge controller. At max possible current, that is around 130 amps @ 48 volts DC, and the controller is only rated at 60 amps max, depending on the controller.

    I think before anyone can help you will need to know more about the setup - which/what panels, how are they wired up, which/how many charge controllers, etc.

    Typically those inverters are set up for backup power, where normally the solar panel power would charge the batteries, and any excess power goes to offset grid power. If AC grid is lost, then the inverter runs off of the batteries. Look in the manual and see if there is a section showing the diagram for backup or standby power wiring.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Electrician trying to help friend !
    I know there are AC in AC Out an Gen connections on the inverter.

    I know the books say things about connections, but I need clarification on what hooks where.

    Sorry for the confusion. :-)

    It's been a while since I worked with one of these, but in the manual there should be several pages of wiring diagrams for different scenarios. Generally, AC in goes to a backfed breaker in the main panel and AC out goes to a protected loads panel. If you had a generator, it would connect to the GEN port.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Electrician trying to help friend !

    If the utility panel is connected to the "AC in" connection on the Xantrex it is physically possible to sell back as-is, not that you can or should. What is the amperage of the circuit breaker in the utility panel? Has the system been inspected and approved for grid-tie use?
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • BB.BB. Super Moderators, Administrators Posts: 32,314 admin
    Re: Electrician trying to help friend !

    Circuit breaker from the main panel to the XW inverter should be around 30-40 amps--Which will give you 6,000 watts of power at 240 VAC... That size cabling will sort of look like "signaling" wire when compared to the huge cables typically used for a 48 volt battery installation (which would be sized to handle around 150-200 amps at 48 volts DC).

    There are lots of things that could be going on or not. From wiring to configuration issues.

    Also, if there is a wind turbine involved--typically those need a second charge controller on the battery bank setup as as "diversion" load controller (basically, when the battery bank is charged and the turbine is still supplying current, the diversion controller turns on a set of electrical heaters to dump the excess charging current from the wind turbine--when the grid power is down and the XW hybrid inverter cannot send power to the grid.

    Anyway, your friend has a very complex system and it will be difficult for us to help without exact information about the configuration and what is happening (voltage, current, status from the controllers, etc.).

    Is the installer still involved? Did the system used to work and stop? Or is this a new install and still trying to get working the first time? etc.

    Are you a licensed electrician?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !

    Page 2-20 of the manual pretty clearly shows what should be connected to what.....from the Xantrex AC section to either the subpanel or the grid tied main panel.

    I don't get what that "signal" wire is from the 200a main panel to the Xantrex unit, nor do I get how the system is being used to run a "small, stand alone panel" in the house.

    It sounds like somebody didn't get the concept of HOW this inverter works, but has managed to get it to work with that "signal" wire.

    The way grid tie with battery backup inverters work is:

    1. Grid is working. The inverter puts all power left after taking care of the batteries out to the grid....that should be to a double pole 30-50amp breaker in the main house panel. ( But be aware that different utility systems have that connection at different places ) That will either feed the house OR run the meter backwards if the house is using less than the system is feeding it.

    2. Grid goes down. The inverter senses the grid down, and the AC contacts that feed out (above) open, and another set of AC contacts ( bypass ) close, diverting the power to a subpanel, isolated by a transfer switch ( locally installed ). One "could" use the main panel, instead of a subpanel, again, isolated from the grid with a 200a transfer switch, but since a 6kw system is only producing about 25amp, you could easily overload that AC breaker out in the Xantrex box, so most folks do a small sub-panel for the bypass situation and only put a few, critcal circuits ( refrigeration, lights, etc ) they want to be sure are always on.

    IF it's connected the way I suspect it is from your description, 3 things wrong: (at least)

    1. That 'signal' wire could be too small to handle the load that could go on it.

    2. The 'stand alone' panel may, or may NOT be using what the system is capable of putting out....depending on the loads there...which means they could have a 6kw system and are using 3kw of it......kind of a silly waste of money.

    3. When the grid DOES go down, as you noted when you flipped off the "signal" wire, NOTHING is happening....no backup power.....the batteries aren't doing diddly in this deal, because nothing is connected to the bypass side of the inverter.....meaning they might as well have just bought a straight grid tie inverter for a whole lot less money than they have in this system ( no batteries, no charge controllers, etc ).


    Like BB said: WHO put this in, and did they know what they were doing ?
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Electrician trying to help friend !
    TnAndy wrote: »
    Like BB said: WHO put this in, and did they know what they were doing ?
    It's not in/near Fredericksburg, TX, is it?
  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    Wow thanks for wanting to help !!!

    Let me address some of the things you all have asked.

    I am a electrican with extensive residential and commerical wiring, I also worked at a substation xfmr plant in the elec. finish dept. ie conduit, motor controllers, control cabs. in cannonsburg, Pa while going to school for electrical technology. Unfortunatly when I went to school PV were not as common place as they are today..

    The person/company that started installing this set-up was in way over their head !!!

    My friend Les has talked to several local people that expressed intrest in configuring his array, but no two people could tell him to do it the same way !

    Here in SW Pennsylvaina solar is not as big it is in the desert SW where this site is from. But with people like you all I think that the knowlegde base is large enough for it to be more a reality that a confusing mess, like the one I am inserting my self into...

    One of you asked about the charge controllers. When I looked this system over WELL for the first time yesterday, I too noticed that with some simple ohm's law math that ONE solar charge controller was not sufficent. I thought that each bank of ten 200w PV's should have it's own controller.

    The Xan. XW6048 also has an optional function controller pad, this system is not equipped with one "Yet"

    Les and I are set to one goal I need you to tell me if its possible.

    Hook up the PVs correctly with each bank of ten 200w PVs with it's own controller to most efficently collect the power being generated.

    Then connect the controllers to the 48v bank of batteries

    Use the 6048 inverter after correctly set-up to transmit power to a primary circuit breaker box that is in the house which is fed from a 200A net metering meter.

    The current installation that is functioning was inspected, but I think that the inspector as was the original installer was mystified by this whole solar set-up.

    I totally agree w BB and Andy they botched this whole thing, and the sad part is this was installed late last fall. So Les has been out time, money and effort and has not sold 1KW to allegheny power.

    Thanks again folks !

    Note: In every illustration in the install manual pictures a power distribution box along with the inverter. There isn't one ! Just an inverter and some wiring.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Electrician trying to help friend !

    "Note: In every illustration in the install manual pictures a power distribution box along with the inverter. There isn't one ! Just an inverter and some wiring."

    now that is a direct contradiction to what you said in your 1st post.

    "The inverters output is connected to a standalone sub-panel in the house which runs a few loads."

    basically you should have 3 connections to the inverter.

    the 1st coming from the batteries to the inverter. dc
    the 2nd coming from the utility to the inverter. ac
    the 3rd going to the sub-panel or distribution panel to power the circuits that are backed up for when the power goes down. ac

    if there isn't a connection to the utility power from the inverter to the main service entrance breaker panel then the pvs are charging the batteries as well as powering the loads on that distribution panel providing that aspect of it is connected up right. as was said we do need more details. i'm also gathering that les obtained you to not only get it to work, but to try to get the install ready to be certified for the utility connection by an inspector.

    btw, 6kw in pv is a fairly large system to run to batteries even though it will be set up to sell after the batteries are charged. in winter around here you will have long stretches of no sun at times as you probably already know, but even with an hour or 2 that is 6-12kwh and in the summer that's liable to jump to around 25-30kwh a day. many people here would drool with even half of that in pv, but some have larger setups and are usually straight grid tied without batteries.

    i was loosely aware that there was a solar company down that way and i guess they went under?

    ps-i do not have a big system here or experience with the xw, but i do have some general understandings and knowledge.
    could you also be specific as to page numbers and detail what you may be confused about?
  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    Hey neil,

    The output of the inverter is hooked to a small cutler hammer ch sub-panel.
    NOT the power distribution box shown in the pictures with the DC disconnect and other AC breakers.

    Sorry for the confusion
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !

    Note: In every illustration in the install manual pictures a power distribution box along with the inverter. There isn't one ! Just an inverter and some wiring.

    Ah, there's part of the problem right there.

    I'm more familiar with Outback gear, but the DC and AC boxes for each side of the inverters ARE separate order items ( unless you buy a pre-built package with the whole shebang together ). Sounds like somebody left off part of the equipment that would have been handy, and necessary, to have.

    Also, on putting 2000w on a charge controller.....you can most likely get up more like 3200w (or more).

    Outback puts a figure right in the install manual, based on battery out voltage. Xantrex uses a more complicated string sizing formula, based on the brand and wattage panel of the system ( taking into account the Vmp and limits of the controller, etc )

    You can find it here:

    http://www2.schneider-electric.com/sites/corporate/en/products-services/renewable-energies/products-offer/sizing-tools-xw.page

    ( Along with a page of legal mumbo jumbo you have to agree to in order to use it )
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !
    niel wrote: »
    btw, 6kw in pv is a fairly large system to run to batteries even though it will be set up to sell after the batteries are charged. in winter around here you will have long stretches of no sun at times as you probably already know, but even with an hour or 2 that is 6-12kwh and in the summer that's liable to jump to around 25-30kwh a day.

    Dead on with the numbers, Niel.

    My 5.95kw system will do 5kwhrs if I get any break in the clouds at all, and 33-34kwhrs on good solar days. Our conditions wouldn't vary much from the PA area.

    That size system SHOULD be pumping 500kw/hrs a month, on average, out for use. One of my best months was this past October at 657kw/hrs for 34 days.
  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    Neil, are you from the PGH area ? This installation is in Monongehela PA.

    Thanks Bernie
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !

    The current installation that is functioning was inspected, but I think that the inspector as was the original installer was mystified by this whole solar set-up.

    Same here when I got mine inspected. He didn't have a clue what he was looking at. His main concern was making sure I had a small disconnect at the solar Kw/hr meter (we use a separate meter here for solar production) so the power company could shut down the solar feed should they need to.

    By the way, some good photos would be nice of the set up, if you can post them. Cut out a lot of confusion.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Electrician trying to help friend !
    Neil, are you from the PGH area ? This installation is in Monongehela PA.

    Thanks Bernie

    yup, that's a bit of a ride down the river from me, but i can see the river from my place. i'm so close to pittsburgh that i say that's where i'm from for illustrative purposes here on the forum.
  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    So I need to get a Power Dist box for the inverter and a digital control screen for the XW inverter and two more of the Xantech solar converters like the one he already has and start fresh with the prints from the install manual.

    Just a curioisity if i have a feed to the (not yet installed) Inverter distribution Panel from the main service entrance, how does the AC energy from the inverter get back to the Main Panel to be back fed through the meter.

    Again thanks for all the input !
  • mikeomikeo Solar Expert Posts: 386 ✭✭✭
    Re: Electrician trying to help friend !

    J
    ust a curioisity if i have a feed to the (not yet installed) Inverter distribution Panel from the main service entrance, how does the AC energy from the inverter get back to the Main Panel to be back fed through the meter.
    The AC "in" of the inverter is where the power gets backfed to the service panel so it is a two way circuit that powers the inverter and can charge the batteries off the grid, and then backfeed to the grid when solar power is being generated. The AC out is just to power backup loads from the battery when there is no grid AC. Otherwise the inverter just passes AC grid power to the backup loads such as fridge, freezers and emergency lighting. The AC "out" works just like a UPS system.
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !
    So I need.... two more of the Xantech solar converters

    Nope......I think only one. Use that sizing tool to be sure, but each charge controller should handle 3000w of panels easy on a 48v system.
    Just a curioisity if i have a feed to the (not yet installed) Inverter distribution Panel from the main service entrance, how does the AC energy from the inverter get back to the

    Same wire.

    Once the batteries are full, the inverter sends the excess power on that wire to the main panel. It will either be used by the house directly at that point, lowering the amount bought, OR it will reverse the meter if the house demand is lower than the amount supplied by the solar system.

    That same wire will feed the inverter to charge the batteries ( buying power from the utility ) if there is an extended period of no sun, and the batteries need charging. ( That's why they are called an "inverter/charger" )
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !
    mikeo wrote: »
    J
    The AC "in" of the inverter is where the power gets backfed to the service panel so it is a two way circuit that powers the inverter and can charge the batteries off the grid, and then backfeed to the grid when solar power is being generated. The AC out is just to power backup loads from the battery when there is no grid AC. Otherwise the inverter just passes AC grid power to the backup loads such as fridge, freezers and emergency lighting.

    Which, of course, is confusing as heck, huh ?

    The AC IN is actually AC 'out/in'.....and the AC OUT, as MikeO says, is actually only AC out when the grid is down. An extra set of contacts in the inverter closes when the grid contacts open ( as they sense "no grid power" ), so you can divert the power elsewhere.

    That AC OUT should go to a transfer switch, with a subpanel of critical circuits in the subpanel that the homeowner wants to run no matter what.....some lights, refrigeration, etc.

    Pic of my setup:

    Main panel, to the far left, white cover.
    Sub panel in the center.
    Manual transfer switch (100a, Cutler Hammer) to flip the sub panel from grid to solar as needed.

    ry%3D480
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Electrician trying to help friend !
    TnAndy wrote: »

    That same wire will feed the inverter to charge the batteries ( buying power from the utility ) if there is an extended period of no sun, and the batteries need charging. ( That's why they are called an "inverter/charger" )
    Sometimes a source of confusion in these systems is that there are two battery chargers operating in parallel - one in the charge controller working with DC from the PV array and the other in the inverter/charger using AC power from the grid. There is a shunt in series with the battery that allows the system to monitor current in and out of the battery bank so that the charge controller knows the battery SOC irrespective of where the charging current comes from.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Electrician trying to help friend !

    also, one more big question is, what size is the main service panel there as the bus has to be able to handle not only the utility power, but also the power outputted by the inverter? in some cases it is necessary to upgrade the main service panel.
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !
    niel wrote: »
    also, one more big question is, what size is the main service panel there as the bus has to be able to handle not only the utility power, but also the power outputted by the inverter? in some cases it is necessary to upgrade the main service panel.


    Yep...but most likely not an issue in this case, since they have a 200amp main service. Output by the solar will be something under 30amp, feed into that double pole breaker in the main service.

    By the way, that is the way they used to allow connection here, but now they are requiring a direct connection on the utility side of the power company meter.
  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    Wow, I guess you all have been down this educational road !

    Photos to follow on Saturday per requests !

    In regards to the PV panels themselves, per your advice I just purchaced a Solar Charge converter that is the same xantrex model as the one Les already has. How do I go about re-connecting 15-200w panels to each controller ?

    Are the panels in Series with each other or Parallel or a mix of both to get a proper range?

    The controller says not to excede 150v MAX. The panels produce 200w should there be a nameplate that says what their output voltage is ? or is that pretty much a industry standard ?

    PS ANDY I like your ideas with the large xfer switch to isolate loads !

    Neil the service entrance is 4/0 alum into a not more than 5 yr old either GE or SQ D. 200 A main panel.
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !
    Wow, I guess you all have been down this educational road !

    Yep. I'm a retired electrician among other things, and this isn't anything like I ever did in the field.


    Are the panels in Series with each other or Parallel or a mix of both to get a proper range?

    Yes....you'll be doing series and parallel. Most likely, about 3-4 panels in series, to make a "string" ( might as well learn the lingo ), then the strings in parallel to a combiner box(s)....and from that, a pair of larger gauge wires down to the charge controller.

    Be interesting to know HOW they are currently wired that they managed to get 30 panels onto that one charge controller.....you might want to describe that in detail when you get time. ( Like did they use a combiner box....and what size....and so on )
    The controller says not to excede 150v MAX. The panels produce 200w should there be a nameplate that says what their output voltage is ? or is that pretty much a industry standard ?

    Yep, not to exceed 150 in, BUT you also have to allow for the most voltage that could be produced on a cold day as well, and de-rate to that. Generally, you'd be looking more like 120-130v in as your max.

    That Xantrex sizing tool I referenced above will give you that info as well. Look at the bottom, and there is a place to put in the record low temps for your area.

    My guesstimate is you'll be doing strings of 3, 10 for the whole array (30 panels), and then take that into a 12 circuit combiner box using 10 of the 12 slots.

    The specs will be on the backs of the panels, OR if you can list the panel brand and model, it can be gotten off the internet.
  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    Andy, I looked at the PV connections. Umm Shakey at best would be the best way to describe it, although they used "liquidtite" and hoffman boxes along with water tight connectors. It looks like an octopuss that fell in spaghetti ! As stated earlier they knew enough to make it work but, not enough to make it work right !

    Im thinking that the string couplers should be the same size as the PV leads and do alittle Ohms law/Voltage drop computations and get the correct trunk line wire ga. to feed the charge converters

    I will sketch a print for you w/ wire ga and such, So you can get a chuckle!!!

    Not so confused in Pittsburgh,
    Bernie

    PS do you know where I could get a good deal on a XW system control panel. I did alittle surfing and found one for 197.00. Good Deal ?
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: Electrician trying to help friend !

    Hmmm.....reckon they cut the panel lead end connectors off and crimped a connector on the extensions ?

    Be intesting to see your sketch and some photos.

    Starting to sound like a horror story in the making....ahahaaaaaa
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Electrician trying to help friend !
    The controller says not to excede 150v MAX. The panels produce 200w should there be a nameplate that says what their output voltage is ?

    Yes, literally there should be a nameplate or sticker on the back of each solar module that lists Voc (open circuit voltage), Vmp (max power voltage), Isc (short circuit current), and Imp (max power current). The number you are interested in is Voc.

    Connecting modules in series adds voltage, so you'll want to construct your series strings so that the aggregate Voc does not exceed 150V at the coldest temperature the system will experience.

    If the charge controller manufacturer has an on-line string calculator on their website, you may just be able to select your module from a pulldown menu and enter the record coldest temperature for your location (I get it from http://www.weather.com/) and it will tell you the maximum string length.

    Alternatively, you can google the module you have and download a data sheet that will tell you the correction factor to use to calculate what Voc will be at the lowest temperature. It will show a number either in % per degree C or mV per degree C (this number actually may be on the module nameplate). Figure the difference from 25 degrees C to your coldest temperature, and calculate a new Voc. The sum of temperature corrected module Voc's in a series string must be less than the maximum voltage allowed by the controller.
  • solarixsolarix Solar Expert Posts: 713 ✭✭
    Re: Electrician trying to help friend !

    Last time I did an XW system, I had to buy the XW remote controller in order to change the setup configuration to allow it to "sell" power to the utility. The XW comes with off-grid mode as its default.
  • THENEXTVETTETHENEXTVETTE Registered Users Posts: 14
    Re: Electrician trying to help friend !

    Any places to get good deals on XW pieces and parts ie the controller?

    I already purchaced the second charge controller for 475.
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Electrician trying to help friend !
    Wow thanks for wanting to help !!!


    I totally agree w BB and Andy they botched this whole thing, and the sad part is this was installed late last fall. So Les has been out time, money and effort and has not sold 1KW to allegheny power.

    We see that VERY often from companies that have only done regular grid tie systems with no batteries. Off-grid and battery backup systems are much more complicated than just plugging in a bunch of panels and running wires, and very few solar installaion companies get it right.
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