Is the system set up right

wiggywiggy Registered Users Posts: 20
Hello

I have joined the forum to try and make sense out of a system I oversee. The system consists of a Perkins Gen 10.5 KVA potential 13.5KVA one Victron Quattro inverter charger 5000W, one Victron Battery charger one spare Victron inverter charger 5000W and fork lift batteries.
We have had an engineer from Holland install this system to his specifications to run automatically a standard size house with well pump aircon units the works

Now to the fun bit. When the system was installed the engineer put the two inverters on different legs of the generator (3 phase) battery charger on another. We continually had problems with the gen breakers tripping out running on and wasting fuel. After many visits by the engineer rewiring of the house new well pump installed by the engineer we continued to have problems, so much so that one of the inverters burnt out a transformer. Whilst the defective inverter was being refurbished the system was configured to run on the existing inverter which it did for a year, with one exception a time lag switch for two of the aicon units direct from the generator. The other inverter came back from the manufacturers with (supposedly the same settings as the inverter in use) The idea was a spare inverter plug and go if needed.
Funny old thing this Last week I visited the house in question only to find no power to the house generator breakers tripped and running on. When I reset the system the inverter tried to switch over to mains on bulk failed, buzzed something awful and smelt like it was burning. I stopped the system called the electrician who has been instructed by the engineer to change out the units.

This done I started the system in auto.

Q. The system has been running for 29 hours charging the forklift batteries. How long ball park figure should bulk absorption and float mode take (I know the system very well and the most I have experienced is 10 hours)

Q. Any ideas why the inverters are burning out on a regular basis. Manufacturing fault or set up fault.

The main problem with this set up is the engineer is not very forthcoming with explanations hence this post, and with this inverter now in place I am pretty sure as an operator that there is something wrong with the amount of runtime to recharge the batteries with no draw from the house at present. I have switched the system off and am now waiting for the owners of this house to talk to the engineer

I am not an engineer or electrician I am a concerned end user, who has lost confidence with this system

Any thoughts would be welcome in its simplest form please

Many thanks in advance:cry:
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Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Is the system set up right

    Welcome to the forum.

    You've answered your own question about "is it set up right" by all the problems that are happening. Obviously it isn't.

    The biggest problem appears to be a 3 phase generator connected to a single phase power system. This is almost certain to cause imbalance on the gen output and trip breakers. Without knowing exactly how it is wired (as in seeing a diagram) it's difficult to say beyond that.

    So let's skip to "fix".

    First question: what are the power needs of the household? Along with that, are two 5kW inverters capable of supplying those needs? If so, are they "stacked" for 230 VAC 50 Hz 10kW power or are the loads divided into separate halves?

    Second question: How is the DC side wired? Separate battery banks for each inverter or all together? (This is where some of the imbalance comes from; one phase running one charger each, as it were.) How large are these batteries (Voltage and Amp hour capacity)? What is the maximum charge rate available from each charger?

    Third question: Any solar power connection, or charging strictly from generator on-demand?

    What needs to be done here is to sort out first the AC supply to the house from the inverters and make sure that is proper and adequate. Then examine the battery capacity and see if it is wired right and sufficiently sized. Finally address the issues of how those batteries get recharged, and if/how the generator's AC is passed on to loads during charging.

    But in the interim it may be necessary to disconnect the batteries entirely and charge them 'out of the system' to bring them back up before sulphation sets in.

    I'll refrain from speculating on the education of the person responsible for this system in the first place. :roll:
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    Welcome to the forum.

    You've answered your own question about "is it set up right" by all the problems that are happening. Obviously it isn't.

    The biggest problem appears to be a 3 phase generator connected to a single phase power system. This is almost certain to cause imbalance on the gen output and trip breakers. Without knowing exactly how it is wired (as in seeing a diagram) it's difficult to say beyond that.

    So let's skip to "fix".

    First question: what are the power needs of the household? Along with that, are two 5kW inverters capable of supplying those needs? If so, are they "stacked" for 230 VAC 50 Hz 10kW power or are the loads divided into separate halves?

    Second question: How is the DC side wired? Separate battery banks for each inverter or all together? (This is where some of the imbalance comes from; one phase running one charger each, as it were.) How large are these batteries (Voltage and Amp hour capacity)? What is the maximum charge rate available from each charger?

    Third question: Any solar power connection, or charging strictly from generator on-demand?

    What needs to be done here is to sort out first the AC supply to the house from the inverters and make sure that is proper and adequate. Then examine the battery capacity and see if it is wired right and sufficiently sized. Finally address the issues of how those batteries get recharged, and if/how the generator's AC is passed on to loads during charging.

    But in the interim it may be necessary to disconnect the batteries entirely and charge them 'out of the system' to bring them back up before sulphation sets in.

    I'll refrain from speculating on the education of the person responsible for this system in the first place. :roll:

    Thanks for the reply I will endeavour to find out the information you have posted, I will post when I have it if that's ok
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    Do you know if the house is wired for three phase (with three phase loads) or these are just two single phase inverter each driving a portion of the home's circuits (i.e., 230 VAC circuits)?

    The inverters should have different output breakers/bus bars (at least one output of each inverter should go to its own sets of loads--and there may be an issue if the other two legs are tied together--or not).

    A 10 kW genset (all three phases added together?) driving one 5kVA inverter/charger, and another driving a battery charger? (plus one spare inverter charger)...

    Typically, I would expect a three phase genset to supply about 1/3rd of the current to each phase--so ~3.3 kW to each load--And it is possible that a 5kW inverter/charger is overloading that one phase (I am not sure how far out of balance you can take current on a three phase genset--it may support more than 1/3rd of the output).

    Anyway--It might be about time to get second party power engineer with three phase generator experience. There are a lot of variables here that may make any suggestions we have pretty much useless in with your real life system. Three phase power can do some really strange stuff with current/resonance if the outputs/loads are not wired correctly.

    One thing that would be helpful is to get a good quality glass hydrometer and thermometer and start measuring the specific gravity of the battery bank. If the battery is deeply discharged and not quickly recharged--You can have issues with the battery "sulftating" (soft lead sulfate turns into hard black crystals and that lead is locked away chemically, never to be part of the charging/discharging cycle again). You want to get the battery bank over ~75% state of charge (probably >90% SOC) quickly as it will "sulfate" if left uncharged for many days/weeks/months--ruining the battery bank.

    Also, you probably want to look for a DC Current Clamp Meter (here is an inexpensive one in the US for ~$60). You can at least measure the charging current to the battery bank and figure out what is happening with the charging current (you want around 5% to 13% rate of charge in normal operation). That is C/20 to C/8 rate of charge--Which means it would take 20 hours to 8 hours to recharge a "dead" battery (really, it will take 2-6 hours more as charging from ~80-90% to 100% can take a few hours by itself to complete as the charging current slowly tapers down to near zero amps (typically to ~2% to 1% of the battery bank's AH capacity).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right

    Thanks for the replies, thus far.

    As mentioned I will get more information however the engineer is a little tight lipped. I would like to clear one thing up if I may. The system was designed to run with the 2 inverters but due to the problems mentioned it is only running with 1. the other sits in its box as a spare. with the 1 inverter the system has run for just under a year with seemingly no problem, however as you guys have mentioned there must be a problem as it has burnt the inverter out in this configuration. Previously when we had both inverters running we had continuing problems gen breaker tripping and an inverter burnt out. So as you can see we have problems in both configurations but at present it is the lesser of two evils

    The system is generator driven no solar or wind power.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Is the system set up right

    What I'm thinking has happened here is that the inverters' AC output has been joined in parallel and each is fed from a different phase of the generator. When the generator is active, the loads are shifted from inverter to generator via internal transfer switch ('pass-through' operation) which would essential short two of the generator's phases. Instant circuit fault.

    But without a little more info we can't be sure.
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    Doing things like measuring input current (with a current clamp meter on each of the 3 phase AC input likes to make sure the values are "reasonable" and not too high) and input voltage (inverters are "constant power" type devices... Power=Voltage*Current). If the generator output voltage starts to sag (operate at minimum voltage or less), the inverter (and charger) can compensate and start drawing more current from the genset to maintain constant power output to the loads (p=v*i -- 20% voltage drop means 20% more current).

    And with current, losses are typically self heating which is P=I2R. So if you get 120% current, then 1.22=1.44 (or 44%) more heat inside the generator/inverter wiring.

    Regarding placing two inverters on the genset and popping breakers. That sounds like the 3 phase power from the genset is not properly isolated from the loads.

    In the US we have a grounded neutral for most power systems (for lightning surge suppression and a way to prevent a high voltage line cross to home/utility customer from exceeding safe limits--I.e., a 120/240 line energized by a 12,000 volt high voltage line falling on the 120/240 volt feed).

    In three phase power, there are to major types of sources (and loads) One is "Delta" and the other is "Wye" (or "Y" connected). If there is grounding of the neutral (don't know how it is done in your country), it can partially short out the generator and/or cause excessive currents to flow in some of the generator windings.

    Three phase power is actually quite complex and very math heavy (see Edison vs Tesla--very interesting story). By contrast, DC and single phase AC power is much easier to understand. And even single phase AC starts getting into the math to understand the differences betwen Watts and VA (volts * amps).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    While having a discussion in another thread, I ran across this paper about three phase connections and grounding issues. The details of the paper are probably beyond most of our abilities here to understand the math--But it gives a good idea on the issues with three phase power and grounding issues:

    Review of Three Phase System Grounding (PDF download)

    This is not a simple issue.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right

    Ok a little more information

    Genset 13.5 KVA 400 / 230 V 50Hz

    Charger 24 / 100 A L1 charger 16 A

    Quattro 24/5000/120 L3 house / shed in 15 A out 20 A

    L2 AC Units/Fans 16A

    Battery set 24V / 840 A

    See link below, hope this gives a bit more info and understanding

    https://dub123.mail.live.com/P.mvc#!/mail/ViewOfficePreview.aspx?messageid=df791cf7-97f9-11e2-81d3-00215ad7f15c&folderid=00000000-0000-0000-0000-000000000001&attindex=2&cp=-1&attdepth=2&n=850567738
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    For some reason, your link is asking me to login to hotmail... Is this a personal email account or some sort of document sharing service?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    BB. wrote: »
    For some reason, your link is asking me to login to hotmail... Is this a personal email account or some sort of document sharing service?

    -Bill

    Sorry about that I cant seem to download this doc, I'll try something else
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right

    Ok I have edited this post I seem to be getting to myself into a pickle trying to load these PDF files so please excuse me I have deleted the names from the documents as advised. Lets hope this is right One doc is the system as it should be the other is the system as it is now

    Attachment not found. Attachment not found.
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    I would still like to know a bit more about the three phase power--Is the genset Delta wound? And the AC loads would like to know L1-L2; L2-L3; L3-L1 or some other (involving neutral and "Wye" would genset where N-L1; N-L2; N-L3, etc...).

    Also--Looking at the first document--It contains the name of the customer (I think)--Do you want to edit that out (the whole Internet privacy issue).

    I will have to spend more time looking at the diagrams.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    BB. wrote: »
    I would still like to know a bit more about the three phase power--Is the genset Delta wound? And the AC loads would like to know L1-L2; L2-L3; L3-L1 or some other (involving neutral and "Wye" would genset where N-L1; N-L2; N-L3, etc...).

    Also--Looking at the first document--It contains the name of the customer (I think)--Do you want to edit that out (the whole Internet privacy issue).

    I will have to spend more time looking at the diagrams.

    -Bill

    Cheers for the advice Bill have edited the documents, regarding the info you require. As mentioned at the outset of this I am just overseeing this villa and as the end user I am the one having to deal with the inherent problems as and when they happen. The owner is pulling his hair out with the amount of money this has cost him and is none to impressed with the engineer. I on the other hand have to deal with the people staying in his villa when it goes wrong, which is not pleasant. Especially as I am retired and quite frankly do not need the hassle. I have told the owner that his choice of engineer is questionable, but I would like to try to understand if this system is set up correctly and just by the posts received already I can see it is not but I already suspected that, and although I'm not an electrical engineer, I certainly know when and when not something is wrong exactly the same as a car, you live with it, know it and can tell when something is not quite right. I appreciate the feed back on this and hope this post has not put anybody off

    So I am limited to providing the information you require, but will do my best

    Thanks
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    I understand the issues and limitations.

    Regarding the genset--Can you give a Mfg. Name/Model number of the unit? I might be able to find the information on the web.

    Basically a Delta wound is three points of a triangle. And the power is drawn from a combination of each end point (L1-L2; L2-L3; L3-L1).

    A Wye wound is sort of like the letter "Y"... In the US, for example, you would get 208 VAC between L1-L2; L..., and between LX and the center of the Y, we would get 120 VAC (L1-Neutral; L2-Neutral, etc.).

    And if everything is done right--You can have Delta sources driving Wye or Delta loads, and other mix/matches... It really is very complex subject (way over my head).

    The center of the Y is usually bonded to earth ground (again in the US). I just don't know anything about European three phase power standards. Delta systems are grounded differently (can be center tape of one transformer winding for 120/240 Split Phase power--the common home power feed in North America).

    -Bill

    PS: I sent you a PM too.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    BB. wrote: »
    I understand the issues and limitations.

    Regarding the genset--Can you give a Mfg. Name/Model number of the unit? I might be able to find the information on the web.

    Basically a Delta wound is three points of a triangle. And the power is drawn from a combination of each end point (L1-L2; L2-L3; L3-L1).

    A Wye wound is sort of like the letter "Y"... In the US, for example, you would get 208 VAC between L1-L2; L..., and between LX and the center of the Y, we would get 120 VAC (L1-Neutral; L2-Neutral, etc.).

    And if everything is done right--You can have Delta sources driving Wye or Delta loads, and other mix/matches... It really is very complex subject (way over my head).

    The center of the Y is usually bonded to earth ground (again in the US). I just don't know anything about European three phase power standards. Delta systems are grounded differently (can be center tape of one transformer winding for 120/240 Split Phase power--the common home power feed in North America).

    -Bill

    PS: I sent you a PM too.

    The model number is Perkins P13. 5-4

    year 2011

    rated voltage 400/230v
    phase 3
    rated freq 50 hz
    speed power factor 0.80 cos 0
    rated current stby 20 A
    rated current prime 18 A
    rated RPM 1500
    alternator connection s_star
    ISO 8528-3 rating pr 500m tlo 875
    alternator enclosure IP23
    insulation class H
    excitation current 2 a
    excitation voltage 40 v
    AVR R250
    mass 580kg

    Hope you can make sense of this as most of a foreign language to me

    Thanks
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    Well--Every foreign language is foreign to me (you probably could include English for me :blush:).

    So, this is a "Wye" "Y" or "Star" wound genset. (from a quick look through the web, most (all?) of these gensets will be "Y" or "Star" wound--so this makes sense).

    The voltage from each output (points of the "Y") to the center of the "Y" is 230 VAC. The voltage from point to point of the "Y" is 230 VAC * srt(3) = 398 (~400) VAC.

    So, the wiring in the home/between the inverters and chargers should all be between L1/L2/L3 and the center of the "Y" which, in North America would be called the "Neutral" and should be tied to a ground rod and/or the cold water pipe (buried in earth) for safety grounding.

    All Lx to Neutral connections should read ~230 VAC. There should be no connections from L1 to L2 (L2-L3 etc.) for any of your single phase 230 VAC load or they would "see" ~400 VAC.

    Ideally, your loads should be evenly distributed between L1/L2/L3 so that no leg is sees too much current. The wiring code should be (per this link):
    FYI - received from collegue in Netherlands.

    Below the colour codes we use in Europe...

    3PHASE:
    Phase L1 Brown
    Phase L2 Black 1
    Phase L3 Black 2
    Neutral Blue
    Safety- ground, instrument-ground Green Yellow

    1PHASE:
    AC Power main current - Brown
    AC Control - Switched main current,
    230VAC controlling current Black
    Neutral Blue
    Safety- ground, instrument-ground Green Yellow

    Other AC Voltage:
    From save altered Current (24VAC, 42VAC ……) Red
    Common from save altered current White
    Safety- ground, instrument-ground Green Yellow

    DC Voltage:
    Phase from save direct current (plc inputs etc) Orange
    Common from save direct current Green
    Measurement signals Yellow
    Voltage initiated in relay assembly Purple
    Hazards direct current Grey
    Safety- ground, instrument-ground Green Yellow

    Not sure about "Black 1" and "Black 2" for phase 2 and 3???

    Note that 3 phase L1/L2/L3 wires are interchangeable with loads--The only time it (usually) matters is when operating a three phase induction motor. If the LX's are connected in the wrong order, the motor will run backwards. The simple fix is to exchange the position of any two LX wires and the motor will turn the correct direction.

    Before we go any farther--This should help you review all of the connections with your system and see if things make sense.

    Basically, your L1-L2-L3 should all be treated as independent 230 VAC voltage/current sources. And all loads should return on the Blue wire to the genset (AC panel, AC inverters, etc.).

    There should be one or more transfer switches that switch the loads between AC Utility, AC Inverters, Backup Genset. These may be separate switches or may be integrated (such as in the AC Inverters). There also be a combination (a pretty complex transfer switch to control Genset/Utilty connections) and a second to for the AC Inverter. Don't know--and details are probably beyond what any of us could support in detail on an Internet forum.

    Where things can get a bit strange is with your AC inverters/Genset connections and the blue/Neutral/Grounding connections.

    Ideally, in the US we use one common point where Earth/Safety ground is bonded to the Neutral bus (blue wire in Europe, white wire in North America). In the US, the generator is assumed to be the only source of power (if over ~3.5-5kW or larger). And we bond the Neutral to Ground in our Main AC panel. What can happen is that we have two earth/neutral bonds--That allows current to the loads to flow in both the Neutral and Earth/Safety ground wire (they are parallel circuit paths). That can cause over heating (Neutral may carry heavier continuous current the safety ground). It can also create circulating currents (i.e., you have a generator neutral/ground bond, and an AC panel Earth/Ground bond because of inverter/utility power assumes that connection).

    A solution may be to lift the Earth/Neutral bond in the genset--Or to install a transfer switch that also switches the Neutral/Ground source too (i.e., Generator ground bond when generator is running, Main AC panel bond when utility power or AC inverters running). This is not a simple A or B solution--It also depends on the detains of the installation and your inverters (some inverters have multiple AC inputs and their own transfer switches).

    Anyway--"The basics". Start with a common block (say your AC Loads). Then look at each system separately (AC loads driving by Utility, AC Loads driven by AC inverter, AC loads driven by Genset) first. Get a handle on that--Then you can look at the other stuff (DC Battery bank inverter/charger connections, etc.).

    Don't try to understand the big picture first--Understand each block and what it does. The big picture will be built on your understanding of each block--And if you get confused (happens to all of us), go back to the block first, then add each additional connection/element.

    I lied a little bit in the previous paragraph. A 50,000 foot view of the the big picture is important and you should understand that. Where people get wrapped around the axle is interactions between all the pieces. Usually, the interactions are not that important. I.e., AC loads driven by genset do not "care" about what happens with the battery+charger.

    You are (probably) having interactions, but until you get the Big/small block picture, it will be difficult to work on these interaction issues. They are complex (both electrically because of generator/inverters/chargers/battery/utility connections and can be mathematically complex with 3 phase power). It is probably 75% an issue with a mistake made in system block connections (i.e., blue wire/green wire bonding, a connection between L1-L2 through some transfer switch/AC load that was not intended but because of all the switches/blocks in this complex system--happened). It could also be issues with circulating currents in the generator windings and the inverters/chargers/etc. and their electrical characteristics--And that may be very difficult to find and understand--even for a power engineer.

    Obviously, you are dealing with high voltage/high current systems here. With automatic and multiple power sources. Be very careful here. If you need to measure current, I would highly suggest spending the money on an AC Current Clamp Meter (or an AC/DC current clamp meter)--The only "safer" way to measure current in operating power systems. So--be very careful.

    Any help?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    Ok--Looking at your drawings a bit more and on the Victron units...

    You do not have utlity power? Correct? And the Quattros have their own AC Transfer switches (actually two, one for grid, one for genset--if I read this right).

    And the Quattros have "generator assist" to supply additional current (from the battery bank) if the loads exceed the generator's output.

    Plus you have a separate 100 Amp @ 24 volt battery charger.

    I assume that you have some sort of setup to allow you to monitor/program your hardware.

    First--Using our standard rules of thumbs--a 900 AH @ 24 volt battery bank would be recommended for a maximum of around 4.5 kW of AC loads--So two 5kW inverter would be a bit large for this bank at full 10kW output (flooded cell batteries--If AGM, it is possible that they would support the surge current, but still a bit small of battery bank for a fully off grid home). Also, 10 kW at 24 volts would be (worst case):

    10,000 watts * 1/21 volts battery cutoff voltage * 1/0.85 inverter eff = 560 amps at full load from low battery bank

    That is a lot of current... Wiring heavy enough to carry that current? Would drain a your battery bank dead in less than 2 hours (probably closer to 1 hour).

    Next, the AC Inverters can be programmed/connected for three phase applications. With two Inverters, can they still be configured for three phase applications (we call this an "open delta" or, I guess open "triangle" in other regions)?

    The reason this is important is that common Neutral "Blue" wire. With AC Neutrals and three phase power (and split phase 120/240 VAC US Power) the phase relationship is important). The 3 phase outputs need to be "coordinated". What happens is the with coordinated phases, the LA to LB currents subtract from the Neutral wire current. If the phases are not correctly coordinated, is is possible for the LA-LB phase current to add.

    Think of a Center tapped transformer.

    Attachment not found.

    The left and right terminals are 180 degrees out of phase (referenced to the Center Tap). We get 120 from LA-Center and LB-Center. And we get 240 VAC from LA-LB.

    If we draw 10 amps LA-Center Tap, both LA and center tap see 10 amps. If we draw 10 amps an LA and 10 amps on LB, then the Center tap sees "zero amps" because the phases are exactly 180 apart. The three phase "Y" center connection is similarly done.

    If your AC inverters are not "phased" and they share an AC Neutral (Blue wire) it is possible for them to put 2x as much current on the blue wire (I hope this makes sense).

    So--Back to your installation. Do you have any idea what "smoked" in your installation (inside the AC inverters)? Was it a Neutral or Ground connection? Or was it something else?

    Regarding charging... Check the DC output of your charger... More or less, batteries are pretty close to 100% efficient when measuring Amps and Amp*Hours...

    If you draw 100 amps from your batteries for 5 hours, that is 500 AH. and if you charged for 100 Amps for 5 hours, that would put 500 AH back into the battery bank.

    More or less, though, the last 10-20% charging of the battery bank is slower as the battries accept less current when nearing full charge... So, as a first approximation, I would guess a 500 AH charger would take around 3-4 hours at near 100 Amp output, and then the balance a slowly declining charge rate for the next 2-4+ hours to fully charge the battery bank.

    You should be using a Hydrometer to measure the specific gravity of the battery's electrolyte--Each cell (temperature corrected). Ideally, you should recharge the battery bank back over >90% charge a couple times a week (not 100% charge every day--that can be hard on the battery with excessive "gassing" and wasteful of generator fuel). And follow the mfg. instructions on equalization (every month or three, or if cell specific gravities are differ by ~0.025 to 0.030 or more from low to high cell).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    BB. wrote: »
    Ok--Looking at your drawings a bit more and on the Victron units...

    You do not have utlity power? Correct? And the Quattros have their own AC Transfer switches (actually two, one for grid, one for genset--if I read this right).

    And the Quattros have "generator assist" to supply additional current (from the battery bank) if the loads exceed the generator's output.

    Plus you have a separate 100 Amp @ 24 volt battery charger.

    I assume that you have some sort of setup to allow you to monitor/program your hardware.

    First--Using our standard rules of thumbs--a 900 AH @ 24 volt battery bank would be recommended for a maximum of around 4.5 kW of AC loads--So two 5kW inverter would be a bit large for this bank at full 10kW output (flooded cell batteries--If AGM, it is possible that they would support the surge current, but still a bit small of battery bank for a fully off grid home). Also, 10 kW at 24 volts would be (worst case):

    10,000 watts * 1/21 volts battery cutoff voltage * 1/0.85 inverter eff = 560 amps at full load from low battery bank

    That is a lot of current... Wiring heavy enough to carry that current? Would drain a your battery bank dead in less than 2 hours (probably closer to 1 hour).

    Next, the AC Inverters can be programmed/connected for three phase applications. With two Inverters, can they still be configured for three phase applications (we call this an "open delta" or, I guess open "triangle" in other regions)?

    The reason this is important is that common Neutral "Blue" wire. With AC Neutrals and three phase power (and split phase 120/240 VAC US Power) the phase relationship is important). The 3 phase outputs need to be "coordinated". What happens is the with coordinated phases, the LA to LB currents subtract from the Neutral wire current. If the phases are not correctly coordinated, is is possible for the LA-LB phase current to add.

    Think of a Center tapped transformer.

    Attachment not found.

    The left and right terminals are 180 degrees out of phase (referenced to the Center Tap). We get 120 from LA-Center and LB-Center. And we get 240 VAC from LA-LB.

    If we draw 10 amps LA-Center Tap, both LA and center tap see 10 amps. If we draw 10 amps an LA and 10 amps on LB, then the Center tap sees "zero amps" because the phases are exactly 180 apart. The three phase "Y" center connection is similarly done.

    If your AC inverters are not "phased" and they share an AC Neutral (Blue wire) it is possible for them to put 2x as much current on the blue wire (I hope this makes sense).

    So--Back to your installation. Do you have any idea what "smoked" in your installation (inside the AC inverters)? Was it a Neutral or Ground connection? Or was it something else?

    Regarding charging... Check the DC output of your charger... More or less, batteries are pretty close to 100% efficient when measuring Amps and Amp*Hours...

    If you draw 100 amps from your batteries for 5 hours, that is 500 AH. and if you charged for 100 Amps for 5 hours, that would put 500 AH back into the battery bank.

    More or less, though, the last 10-20% charging of the battery bank is slower as the battries accept less current when nearing full charge... So, as a first approximation, I would guess a 500 AH charger would take around 3-4 hours at near 100 Amp output, and then the balance a slowly declining charge rate for the next 2-4+ hours to fully charge the battery bank.

    You should be using a Hydrometer to measure the specific gravity of the battery's electrolyte--Each cell (temperature corrected). Ideally, you should recharge the battery bank back over >90% charge a couple times a week (not 100% charge every day--that can be hard on the battery with excessive "gassing" and wasteful of generator fuel). And follow the mfg. instructions on equalization (every month or three, or if cell specific gravities are differ by ~0.025 to 0.030 or more from low to high cell).

    -Bill

    Cheers Bill for taking the time out to do all this. Its a lot of info for me to take in so I'm going to have to read and read again, but just from the body of this I can see that this system is not set correct. I really do not know what smoked the inverter (quattro or is smoking them inside a year) but I did notice Friday that the battery charger was doing its thing in absorption mode whilst the inverter (quattro) was trying to do its thing in float mode. Now as mentioned I am not an engineer but its things like this (that I noticed by chance) that really does drop my confidence in this system, especially as its now been run for 36 hours and still it has not completed a cycle. You are right it is an off grid system relying on the genset to provide the extra power as demanded. The other side of this system is the fact that it is also automatic (or supposed to be) It therefore has a power wizard control panel fitted to the gen (sorry should have mentioned that) that monitors the gen and I assume talks to the Quattro's. Bottom line is though, it don't work and unless the owners get a second opinion I dont think it ever will.

    Oh hum

    We plod on
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    Yea--Complexity to solve problems creates worse problems.

    One thing--It is not unusual for two (or more) charge controllers charging the same battery bank to not be in the same "charging phase".

    Infact, there will be times when they will be not in "sync" (transitioning from bulk to absorb to float is almost never in sync)--Unless the charge controllers are connected together and deigned to have one master controlling them all.

    As long as the charge controllers are making "approximately" correct decisions based on their available inputs--Then I would not get too concerned about it.

    Batteries and charge controllers (in absorb and float mode) are actually sensitive voltage meters that then control their output current based on the observed voltage.

    It is not unusual to have a few tenths of a volt (or higher in 24/48 volt systems) of disagreement and one charger take 100% of the absorb current while the other is near zero (or even in float).

    Just look at each charge controller as a stand alone unit... If it thinks the battery voltage should e at 52.0 volts and the other controller thinks it should be at 52.4 volts--Then the controller that thinks the battery should be at 52.4 volts will "win" and provide most of the current to the battery.

    As long as neither controller is doing anything "wrong" (over current, over/under voltage) then All is OK.

    With some systems (such as wind and solar)--It can get into some "strange states"... Where the solar controller thinks it needs to keep the battery at 58 volts charging and the "dump" controller (dumps excess charging current from a wind turbine into an electric heater/load bank) things the bank voltage should be 52 volts--You have the solar controller energy being wasted/dump into the load bank.

    Similar issues--You have a solar charger and a generator charger.... You want the solar charger to provide as much energy as possible when the sun is up, and the generator to only provide backup charging when needed... You don't want the generator to supply all the charging current and the solar as standby (and waste all that expensive fuel).

    Anyway--Good luck and let us how everything goes.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    BB. wrote: »
    Yea--Complexity to solve problems creates worse problems.

    One thing--It is not unusual for two (or more) charge controllers charging the same battery bank to not be in the same "charging phase".

    Infact, there will be times when they will be not in "sync" (transitioning from bulk to absorb to float is almost never in sync)--Unless the charge controllers are connected together and deigned to have one master controlling them all.

    As long as the charge controllers are making "approximately" correct decisions based on their available inputs--Then I would not get too concerned about it.

    Batteries and charge controllers (in absorb and float mode) are actually sensitive voltage meters that then control their output current based on the observed voltage.

    It is not unusual to have a few tenths of a volt (or higher in 24/48 volt systems) of disagreement and one charger take 100% of the absorb current while the other is near zero (or even in float).

    Just look at each charge controller as a stand alone unit... If it thinks the battery voltage should e at 52.0 volts and the other controller thinks it should be at 52.4 volts--Then the controller that thinks the battery should be at 52.4 volts will "win" and provide most of the current to the battery.

    As long as neither controller is doing anything "wrong" (over current, over/under voltage) then All is OK.

    With some systems (such as wind and solar)--It can get into some "strange states"... Where the solar controller thinks it needs to keep the battery at 58 volts charging and the "dump" controller (dumps excess charging current from a wind turbine into an electric heater/load bank) things the bank voltage should be 52 volts--You have the solar controller energy being wasted/dump into the load bank.

    Similar issues--You have a solar charger and a generator charger.... You want the solar charger to provide as much energy as possible when the sun is up, and the generator to only provide backup charging when needed... You don't want the generator to supply all the charging current and the solar as standby (and waste all that expensive fuel).

    Anyway--Good luck and let us how everything goes.

    -Bill

    Thanks again Bill that is at least good to know. I will let you know the out come of all of this, that is of course my head does not exploded first:D
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    wiggy wrote: »
    Thanks again Bill that is at least good to know. I will let you know the out come of all of this, that is of course my head does not exploded first:D

    Hey up Bill Things have been agreed although not by myself. The engineer has kidded the owner to buy yet more equipment and change the system. I have put in his proposal. I think the owner is mental and have tried to persuade him to get another engineer but ho hum an all that, your thought would be well received:

    From Engineer:

    After a good talk with the senior of Victron Service and a field engineer we found two solutions to get rid of disturbance and ground loops. His advice is either add an isolation transformer before each unit. So ground is separated from the Gen (the power source).

    Or option two is more straight forward: The history tells you started with 2x12 volt Combi's, then 2 x 24 volt Multi's, then 2 x 24 V Quattro's and still it's not working perfect. All the units have the automatic switching, form inverter to charger in them. Also they have to coop with high loads, high temperatures and high peak demands.

    So Advice 2: Change the single charger for two 3-fase chargers. You will have a steady flow of 24 volt 200A max going into the battery, with a maximum power draw of 80% of the gen power used without peaks and lows. Very steady power draw because spread over the 3-fases permanently when gen runs.

    To provide power to the house, use two inverters permanently instead of Quattro's. The two are inverters only.. The inverters will be connected to the battery, so not connected directly to the gen. When battery is low, gen will start and the 2 chargers will fill the battery up again.

    The advantage: No more switching in units (with power drops and peaks going throught the system). You still have the ground protection in the house. No direct connection at all from gen to house. The balanced use of the 3-phase gen. The clean output of 230 Volt into the house. It can all run together and the battery will be the power-buffer.

    No-1 option is only adding more stuff to the system, not very cost effective.

    This no-2 option is the safest one and I wish I thought of it earlier. Me and Victron are willing to trade the ones in and sent the new units to your house. I am willing to spend my time for free.

    Above means with option two:

    2 x 3-phase chargers 24-100A

    2 x 24-5000 inverter only

    1 x Global Remote 2 wired or SIM

    1 x Works, Flight, transportation Spain.

    -2 x Quattro 24/5000/120 (one refurbished already here). return

    -1 x single phase charger 24-100 return


    Thanks for your comments in advance
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    Hooo boy... You are in it deep there.

    I will make some statements--But me not being there and also not any sort of large three phase power systems expert--I would suggest these as concerns to do more research about the issues (yea--you know the drill--second and third opinions).

    Adding more transformers to a poly phase system--I worry about "resonance" where you still have "circulating currents" between all of the interconnected and not interconnected hardware (circulating/resonance currents between the common point--the generator, and the individual transformers/chargers/inverters. You might want to work with a local generator "expert" and see what he recommends (he may have some experience with "hybrid" power systems--Generator for heavy loads/battery charging, and using battery bank+inverters for periods of lighter loads).

    For example, here is a PDF on generator harmonics and battery chargers:

    https://www.cumminsgeneratortechnologies.com/www/en/media/whitepapers/Winding%20Pitch%20White%20Paper_EN_LR.pdf

    You might take a look through Cummins' white papers and see if they are of any help.

    https://www.cumminsgeneratortechnologies.com/en/media/whitepapers/ (they seem to have more than this scattered throughout their site)

    The second solution sounds like a less complex setup and simply runs the home 24x7 from inverter+battery bank, and the genset is there to recharge the battery bank (and supply DC power to the inverters).

    That may use more fuel (extra conversion losses, from AC to DC to AC, vs AC from the genset). Also, running the genset at 80% loading should be a good thing (for the diesel motor) but need to make sure the alternator does not overheat from hours of >80% loading (and possible "harmonics" created by the battery chargers--Good chargers with power factor correction and such should behave better than a "simple" charger with a transformer and rectifier--Which creates very "spiky" current waveforms). Having a simple AC transfer switch to allow the home to run AC power directly from the genset is going to be helpful (more fuel efficient on heavy power days, and allow to bypass failed inverters--if that happens).

    An alternative would be to look a replacing the present generator with a DC output version instead designed to sustain battery banks. Saves the AC to DC conversion losses and would be a system designed to maintain large battery banks (of course, you lose the AC backup power/bypass option).

    If I remember correctly, there are no plans to install solar panels to reduce fuel usage?

    Good luck,
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    BB. wrote: »
    Hooo boy... You are in it deep there.

    I will make some statements--But me not being there and also not any sort of large three phase power systems expert--I would suggest these as concerns to do more research about the issues (yea--you know the drill--second and third opinions).

    Adding more transformers to a poly phase system--I worry about "resonance" where you still have "circulating currents" between all of the interconnected and not interconnected hardware (circulating/resonance currents between the common point--the generator, and the individual transformers/chargers/inverters. You might want to work with a local generator "expert" and see what he recommends (he may have some experience with "hybrid" power systems--Generator for heavy loads/battery charging, and using battery bank+inverters for periods of lighter loads).

    For example, here is a PDF on generator harmonics and battery chargers:

    https://www.cumminsgeneratortechnologies.com/www/en/media/whitepapers/Winding%20Pitch%20White%20Paper_EN_LR.pdf

    You might take a look through Cummins' white papers and see if they are of any help.

    https://www.cumminsgeneratortechnologies.com/en/media/whitepapers/ (they seem to have more than this scattered throughout their site)

    The second solution sounds like a less complex setup and simply runs the home 24x7 from inverter+battery bank, and the genset is there to recharge the battery bank (and supply DC power to the inverters).

    That may use more fuel (extra conversion losses, from AC to DC to AC, vs AC from the genset). Also, running the genset at 80% loading should be a good thing (for the diesel motor) but need to make sure the alternator does not overheat from hours of >80% loading (and possible "harmonics" created by the battery chargers--Good chargers with power factor correction and such should behave better than a "simple" charger with a transformer and rectifier--Which creates very "spiky" current waveforms). Having a simple AC transfer switch to allow the home to run AC power directly from the genset is going to be helpful (more fuel efficient on heavy power days, and allow to bypass failed inverters--if that happens).

    An alternative would be to look a replacing the present generator with a DC output version instead designed to sustain battery banks. Saves the AC to DC conversion losses and would be a system designed to maintain large battery banks (of course, you lose the AC backup power/bypass option).

    If I remember correctly, there are no plans to install solar panels to reduce fuel usage?

    Good luck,
    -Bill

    Cheers Bill

    I have just had an email from the owner, and he has been advised from FG Wilson (Supplier of the genset and the cheapest option) to have the gen converted to a single phase output and use the Quattro's as master slave config, which incidentally is how the old system worked for many years. Looks like the engineer (joke) has really taken the owner for a ride here. Thanks for your comments I hope that this will be resolved soonest, and I will of course keep you posted. The problem we are having is finding someone to take this on. We will get there I'm sure but it is very frustrating non the less, and the owner I hope has learnt a lesson albeit an expensive one.

    Thanks for now
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    If you can do it with a single phase for a reasonable cost--That is probably the start of a good solution for you and the owner. Three phase is wonderful stuff--But really only useful if you have native 3 phase loads (or a very large power grid where you can reasonably distribute loads among the three phases) (in my humble opinion).

    Take care,
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right

    Hi Bill

    Thought I would drop you a line, with an update. The system is at last back up and running albeit on a temporary set up, which has to be further improved. The old engineer has been well and truly sacked fired call it what you will and at last we have an engineer who seems to know what is needed (fingers crossed). Needless to say I wish the owners of the villa had listened in the first instance and most of this could have been avoided.

    Thanks for all your input in this matter it did help by giving an understanding of what is required. We are not out of the woods yet but I hope we are on the right path


    The System
    System set up
    1. Generator and Quattros are now separated from each other by the battery pack.
    2. Installed two 3 phase 100 Amp battery chargers to charge the batteries.
    3. All Victron units properly earthed.
    4. Quattros are NOT linked. Q1 still runs the house, Q2 still runs the water pump and 2 air con units. The reason these are not linked is that they are two different models which don’t talk to each other. To work together we need to upgrade one.
    5. The Quattros work with two virtual switches:
    * Load: Q1 is set at 2.5KW, Q2 is set at 1.8 KW
    * Voltage: drop to 23.5V or less
    These switches start the generator which will run for an hour after being in float for 10 mins.
    6. The Aircon units in bedroom 2 and 3 still work off the timer switch. The timer does NOT start the generator but the Q2 load has been set lower so that the generator will start earlier.
    7. The battery monitor has been removed as it does not work and requires replacing.
    8. The old charger is still connected but it switched off and should NOT be used.
    9. The backup generator is not connected and cannot be used at present.
    10. The earth connection to the earth rod has been improved which has reduced the light flickering in the villa. Note there is no earth connection from the Generator Shed to the house so the Victron units have never been earthed!
    What this means
    1. The house has only 5KW of continuous power available from Q1. If it is exceeded it may reset. This could be automatically or manually depending on what causes it. This may mean visits to reset the power. We need to monitor this to decide if it is a major problem or an occasional issue. Also, we need to explain to the guests that if the power drops to turn something off until it comes back up and then use carefully so as not to overload the system.
    2. The lack of the battery monitor means we cannot use the charge (ampage) to monitor when the batteries need recharging. Consequently, the voltage switch has been used as a temporary solution but is less reliable. The load and voltage switches have been set low to partially compensate by getting the generator to start earlier.
    3. The batteries will benefit from an extended period of charging from time to time. When you are onsite (for example doing a meet and greet or doing the pool) it would help to run the generator on manual for as long as possible. When the villa is empty over winter the system should be run in manual for 6-8 hours every 2 -3 weeks.
    What is still to be done
    1. The battery monitor needs to be repaired or replaced and the wiring modified to install it.
    2. A consumer unit installed in the shed to provide circuit breakers to all the Victron units to protect them from power surges.
    3. Work out a way to use the backup generator – the intention is to use the old charger but it was playing up and we need the battery monitor to work out if it still works or is broken.
    4. Upgrade the older Quattro if required.


    Regards

    Terry
  • BB.BB. Super Moderators, Administrators Posts: 31,765 admin
    Re: Is the system set up right

    Hi Terry, thank you for the update.

    I am very happy to hear that you are seeing light at the end of the tunnel (and it is probably not an oncoming train ;)).

    Did you learn anything interesting from the new engineer? Besides grounding, did he see any other major three phase power related issues (or configuration/wiring issues that were not obvious)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Is the system set up right
    wiggy wrote: »
    Thought I would drop you a line, with an update. The system is at last back up and running albeit on a temporary set up, which has to be further improved. The old engineer has been well and truly sacked fired call it what you will and at last we have an engineer who seems to know what is needed (fingers crossed). Needless to say I wish the owners of the villa had listened in the first instance and most of this could have been avoided.

    Thanks for all your input in this matter it did help by giving an understanding of what is required. We are not out of the woods yet but I hope we are on the right path

    If there is Internet service to the villa (satellite, cellular, whatever) you might want to invest in a battery monitor that can be connected to a network. That way you could remotely check on what the guests are doing to the batteries and contact them to take corrective action before they run out of power and call you or the owner.
    SMA SB 3000, old BP panels.
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    BB. wrote: »
    Hi Terry, thank you for the update.

    I am very happy to hear that you are seeing light at the end of the tunnel (and it is probably not an oncoming train ;)).

    Did you learn anything interesting from the new engineer? Besides grounding, did he see any other major three phase power related issues (or configuration/wiring issues that were not obvious)?

    -Bill

    Hi Bill yer we did learn some new things from the engineer, There were more than one wiring issues, the fact that the two quattros were incompatible was not good. Im sure the owner will get a full list of faults emailed to him, but for now the train is sitting in the in the station and we have a system that is doing its thing, If I get any-more info I'll pass it on

    Kind regards
  • wiggywiggy Registered Users Posts: 20
    Re: Is the system set up right
    inetdog wrote: »
    If there is Internet service to the villa (satellite, cellular, whatever) you might want to invest in a battery monitor that can be connected to a network. That way you could remotely check on what the guests are doing to the batteries and contact them to take corrective action before they run out of power and call you or the owner.

    HI

    Yer we did have supposedly a battery monitor that could be connected to a network but guess what, it never worked and was found to be faulty. I do not know if the owner will go down that route again hey hum
  • garlmikegarlmike Registered Users Posts: 14
    Re: Is the system set up right

    If you fail to Plan, You Plan to Fail..

    I think you need more battery amp hours, the single biggest mistake every first time user makes.
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