I bit the bullet, panels etc to be delivered on Monday - Page 3





Page 3 of 5 FirstFirst 1 2 3 4 5 LastLast
Results 41 to 60 of 89
  1. #41
    Join Date
    Apr 2016
    Location
    Johannesburg
    Age
    68
    Posts
    216
    Thanked: 44

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Quote Originally Posted by JohanMaree View Post
    The following 30 days totalled 701.4 Eskom units.

    Quite a constant.

    But...

    I have a question for the gurus;

    It happens on overcast days when the shop area draws too much power which the panels cannot keep up with. Then somebody has to physically change over to Eskom or the inverter will shut off when the batteries are run down.

    When that "somebody" is not present it is a problem. Due to my inverter is free standing from the PV system and still old school it does not have this facility to do an automatic changeover like the present modern units.

    I cannot find on the market a switching system that can be added to the circuit.

    I would like to
    - Install a monitor that reads the DCV. When it reads 44V it needs to trigger a contactor
    - The contactor should be a minimum 20A AC potential which will switch the Eskom on to recharge the batteries.
    - A timer (not a problem to obtain) to switch back to battery power after say one hour of charging
    - All to be installed in a small surface mount box.

    Any ideas?

    Please do not recommend me buying a new inverter.
    What inverter do you have? (All I see on this post is 6kVA)
    Inverters/UPS will shutdown when the battery voltage drops below a critically low level.
    For an inverter of this power not to provide remote access to this circuit is unusual..
    Last edited by Richard Mackay; 2019/01/30 at 07:34 PM.

  2. #42
    Join Date
    Jun 2008
    Location
    Hillrise, Kempton Park
    Age
    64
    Posts
    1,582
    Thanked: 579

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Richard

    My inverter is old school, nine years old and does not have that facility built in.
    Last edited by JohanMaree; 2019/01/30 at 08:18 PM.
    Isuzu 300 d-tec
    MB Gwagen G350 Bluetec
    Nissan NP300 2.4 4x4
    BMW R1200GS & GSA

  3. #43
    Join Date
    Apr 2016
    Location
    Johannesburg
    Age
    68
    Posts
    216
    Thanked: 44

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Ok. I can provide the control that does the switchover at 44V
    Presently it will switch back when the voltage recovers above 50V approx.
    Do you need to be able to adjust these values??

  4. #44
    Join Date
    Jun 2008
    Location
    Hillrise, Kempton Park
    Age
    64
    Posts
    1,582
    Thanked: 579

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Hi Richard

    Thanks. This looks promising.

    The inverter charges fast and the batteries will reach 50+ in no time which may result in a switch back too soon. I was thinking in the lines of 1 hour at least?

    If adjustable will be great as the optimum V is around 56V when the batteries are fully charged.

    Presently the timer system is set to switch Eskom on at 6-8:30AM (to assist when the shop fridges start up and draw +20A before the sun activates the PV) and evenings from 4-9PM. During the off-times the PV (daily) and batteries (night) handles the draw quite well...

    ...except when it becomes overcast where the switch is then required.

    With this automatic switch I can eliminate the above set times and so decrease the number of Eskom hours even further.
    Isuzu 300 d-tec
    MB Gwagen G350 Bluetec
    Nissan NP300 2.4 4x4
    BMW R1200GS & GSA

  5. #45
    Join Date
    Apr 2016
    Location
    Johannesburg
    Age
    68
    Posts
    216
    Thanked: 44

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    I need to see your system so I don't ask 1000 questions on the forum..
    When is a good time to make a draai? (Preferably when the sun is shining!)

  6. #46
    Join Date
    Jun 2008
    Location
    Hillrise, Kempton Park
    Age
    64
    Posts
    1,582
    Thanked: 579

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    PM Sent
    Isuzu 300 d-tec
    MB Gwagen G350 Bluetec
    Nissan NP300 2.4 4x4
    BMW R1200GS & GSA

  7. #47
    Join Date
    Dec 2013
    Location
    Benoni
    Age
    70
    Posts
    287
    Thanked: 76

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Richard (and Johan),
    Just a curious question from my side;

    How do you measure the status of the batteries while they are charged and power is drawn from them??

    Your system basically consists of:
    Either (or both) Eskom (220V) or Solar Panels charge the batteries, and the Inverter draw current from the batteries.
    Normally charging is done at a reasonable constant voltage, and the charging Current will vary depending both on the battery charge status AND the power drawn by the inverter.

    Do I miss something obvious?
    Herman Meyer.

    AG0017 ORRA AG38
    2014 Amarok DC 4Motion Auto ,
    2015-02-03: Bush Lapa Miskewer 394.

  8. #48
    Join Date
    Dec 2009
    Location
    Centurion
    Age
    46
    Posts
    1,156
    Thanked: 37

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Quote Originally Posted by JohanMaree View Post
    For the past eight years we have the following standby system for our house, spaza shop and diesel depot.
    - 1x 6kW inverter
    - 4 banks of 48V (4x105Ah) batteries.

    Lately I tested their performance during the night from 18h00
    - Up to about 09h00 the next morning we use +-11kWh and we switch over to mains with batteries at around 15% (as per the inverter panel)

    On a normal 24h-day with mains we use +-44kWh average

    I have now ordered the following
    SOLAR PANEL 320 WATT EXTRA ADVANCED A GRADE - T 1 16off for R34 165.12
    MPPT 80 Amp/hr Flexmax FM80 12/24/48/60V OutpT fan/heats com R9 291.00
    VAT Excluded

    Installation on Tuesday and then the test.

    We will still have Eskom as backup for "rainy days". Impossible to cut Eskom completely as we have factories running on the premises. Average monthly account of
    R16 000.00
    Bit late to the thread... but your deltec's will be toast before to long is you cycle them that deep...
    JT

  9. #49
    Join Date
    Apr 2016
    Location
    Johannesburg
    Age
    68
    Posts
    216
    Thanked: 44

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Quote Originally Posted by hermanm10 View Post
    Richard (and Johan),
    Just a curious question from my side;

    How do you measure the status of the batteries while they are charged and power is drawn from them??

    Your system basically consists of:
    Either (or both) Eskom (220V) or Solar Panels charge the batteries, and the Inverter draw current from the batteries.
    Normally charging is done at a reasonable constant voltage, and the charging Current will vary depending both on the battery charge status AND the power drawn by the inverter.

    Do I miss something obvious?
    Good question. I haven't seen Johan's system yet so I'm shooting from the hip..
    The standard way is to look at the inverter battery indicator which will indicate the charge of the battery based on their voltage.
    I accept this might not be perfect but one can get used to your system and interpret the readings pretty accurately!
    (Johan: Wat se jy??)

  10. #50
    Join Date
    Jun 2008
    Location
    Hillrise, Kempton Park
    Age
    64
    Posts
    1,582
    Thanked: 579

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Quote Originally Posted by Richard Mackay View Post
    Good question. I haven't seen Johan's system yet so I'm shooting from the hip..
    The standard way is to look at the inverter battery indicator which will indicate the charge of the battery based on their voltage.
    I accept this might not be perfect but one can get used to your system and interpret the readings pretty accurately!
    (Johan: Wat se jy??)
    Ek sÍ

    Die inverter alarm wanneer die batterye laag loop en wys die V.
    My multimeter stem saam met die lesing.
    As ek dit ignoreer skakel die inverter af om die batterye te spaar.

    Dit is dan wanneer ek die AC outomaties wil aanskakel om die batterye weer te laai terwyl die stelsel op AC loop.

    Vergeet van die PV vir hierdie oefening.
    Isuzu 300 d-tec
    MB Gwagen G350 Bluetec
    Nissan NP300 2.4 4x4
    BMW R1200GS & GSA

  11. The Following User Says Thank You to JohanMaree For This Useful Post:


  12. #51
    Join Date
    Oct 2013
    Location
    Centurion
    Age
    62
    Posts
    635
    Thanked: 254

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Johan ek het vir jou 'n PM gestuur wat dalk kan help.

  13. #52
    Join Date
    Jan 2008
    Location
    George
    Age
    60
    Posts
    3,809
    Thanked: 284

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Having followed the thread on and off since Johan posted I am finally going to have my little say
    Firstly I think it's great, well done and I like your controller, it is a MENEER. I realize that (like my tiny system) you have grown it over a number of years and are therefore tied into an "older" system and technology, which I would be quite happy with. Looking at your requirements in a new system, Lithium Iron grid tie system would have been the way to go ...
    My only negative comment is (and will remain) those 105a/h batteries ... ooooo, I really dislike them. Having had both the sealed lead acid 105's (various makes) and the 150a/h Trojans (requiring a bit of maintenance once every 6 weeks) I find the Trojans simply in another class. They are just so much better and can really take the punch. When it comes time to replace your batteries have a good look at them. There are so many that are just so much better ...https://www.trojanbattery.com/

    Four Wheel Drive Club of SA
    Garden Route Division
    A Proud member of SCROF (Southern Cape Route Owners Forum) see our website at www.4x4ineden.co.za

  14. #53
    Join Date
    Jun 2008
    Location
    Hillrise, Kempton Park
    Age
    64
    Posts
    1,582
    Thanked: 579

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Thanks Dave.

    Yes, I would prefer the Trojans also. Have them in my 48V golf cart.

    However.

    Using the cart for the last 10 years I find the Trojans do not last as long as they used to. Maybe fault on my side.
    Isuzu 300 d-tec
    MB Gwagen G350 Bluetec
    Nissan NP300 2.4 4x4
    BMW R1200GS & GSA

  15. #54
    Join Date
    Dec 2013
    Location
    Pietermaritzburg
    Age
    53
    Posts
    414
    Thanked: 69

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Nice thread Johan, I think we all wander around here dreaming of doing the deed, kudos for taking the plunge I trust it will pay off in time.

    I am looking for some nspiration on how to tidy my battery array away. Would you care to share a picture of your battery bank?
    Pajero Sport 2013 3.2 A/T

  16. #55
    Join Date
    Jun 2008
    Location
    Hillrise, Kempton Park
    Age
    64
    Posts
    1,582
    Thanked: 579

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Tallhorse.

    My battery bank is still open and untidy. No pic now.

    When the PV and V management is up to expectations I will built a neat box around the batteries
    Isuzu 300 d-tec
    MB Gwagen G350 Bluetec
    Nissan NP300 2.4 4x4
    BMW R1200GS & GSA

  17. #56
    Join Date
    Mar 2017
    Location
    Pretoria
    Posts
    51
    Thanked: 28

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    I could be wrong but your PC array is way over the limit for your mppt. I have a similar size schubart inverter and for a 48v system the limit is around 3000w and you are over 5000w .

  18. #57
    Join Date
    Mar 2017
    Location
    Pretoria
    Posts
    51
    Thanked: 28

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Pv

  19. #58
    Join Date
    Mar 2017
    Location
    Pretoria
    Posts
    51
    Thanked: 28

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Similar size mppt

  20. #59
    Join Date
    Oct 2010
    Location
    Pretoria
    Age
    60
    Posts
    1,327
    Thanked: 317

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Quote Originally Posted by Mbu View Post
    I could be wrong but your PC array is way over the limit for your mppt. I have a similar size schubart inverter and for a 48v system the limit is around 3000w and you are over 5000w .
    You will find that during the last month in Gauteng a 5kW array mounted at 30deg would net an effective 3kW during the day in mid summer. Lots of cloud cover the last month.

  21. #60
    Join Date
    Oct 2013
    Location
    Centurion
    Age
    62
    Posts
    635
    Thanked: 254

    Default Re: I bit the bullet, panels etc to be delivered on Monday

    Some days I find with lots of cloud cover that my total yield seems to be close to average but Thursday I was down 40% and Friday down 20%.

Page 3 of 5 FirstFirst 1 2 3 4 5 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •