Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

tonygcan
tonygcan Solar Expert Posts: 91 ✭✭✭✭
in Grid Tie and Grid Interactive Systems #1
Hello.

I have just installed the following system to my home.

12 - 185 watt sharp PV panels (2220 watts total)
8 rolls 6 volt, 450 amp-hour Rolls batteries (connected in series for a 48 volt system).
1 - XW4048 120/240 inverter charger
1 - Xantrex Solar Charge Controller

I was wondering if you guys could help answer some questions:

All the green lights on the inverter charger that indicate battery level are lit-up, which I take to mean that the batteries are fully charged. However in the XW Solar Charge Controller the BATLEVEL indicator only shows about 3/4 full. I wonder which gauge I should trust?

The Xantrex XW inverter charger is a hybrid unit which has an AC IN (GRID) terminal. I have not switched on the breaker that connects the grid to this terminal. Is this AC IN (GRID) terminal meant to charge the batteries during the days when the sun is not enough to charge the batteries?

If so, will the XW4548 charge the batteries automatically or do I need to manually program the inverter charger to do this?

Also, the inverter charger tries o connect to the grid when there is minimal load in the system. My country's utility company does not have any provision to accept feed-in electricity from solar systems. Is there any way to prevent the inverter charger from trying to supply the grid with electricity?

I apologize for the newbie questions but this is also the first time my installer has setup a similar system.
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Comments

  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #2
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

    Tony, Your system sounds great, but your missing the most important piece. Xanterx SCP ( System Control Panel ) without it you are very limited to what you can do. With Rolls batteries you are going to have to program some special charging perimeters.

    Before you can know what to believe about your Batteries you'll have to get the SG's with a hydrometer, then you can reset everything. You really need to equalize them and get your baseline set so you have a constant to get back to when charging.
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #3
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

    Thank you Blackcherry. Yes I do have the Xantrex SCP. That is the one one that reads the batteries to be at 3/4 full. It has an E---F symbol where the battery charge level is. Is there any documentation I can research to see how to program my setup? Thank you!
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #4
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

    BTW, what's an SG?
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #5
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?
    tonygcan wrote: »
    Thank you Blackcherry. Yes I do have the Xantrex SCP. That is the one one that reads the batteries to be at 3/4 full. It has an E---F symbol where the battery charge level is. Is there any documentation I can research to see how to program my setup? Thank you!
    I am sure that others will post that know much more than I do.

    http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CC0QFjAA&url=http%3A%2F%2Fstatic.schneider-electric.us%2Fdocs%2FElectrical%2520Distribution%2FSolar-Energy%2FConext%2520XW%2520Installation%2520Guide.pdf&ei=Ar20ULbnB-mu2QWu94HQAQ&usg=AFQjCNFIQK4x0mLvQJnCDzIOgVnby8k-tA
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #6
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?
    tonygcan wrote: »
    BTW, what's an SG?
    Specific Gravity = SG , The mix of the electrolyte acid in the Battery cells.
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #7
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

    Oops! My installer just returned the operations guide manual to me. I only had the installation guide and thought that was it. The operations manual answers the questions I had. Thanks!
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #8
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?
    tonygcan wrote: »
    Oops! My installer just returned the operations guide manual to me. I only had the installation guide and thought that was it. The operations manual answers the questions I had. Thanks!
    Cool, Study it for a while and then post in Off-Grid area because what you need answered is more than likely get more play there. There are a few things you should start doing now before you get into a problem that gets harder to dig out of.
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  • jeffkruse
    jeffkruse Solar Expert Posts: 205 ✭✭✭
    #9
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

    Please get a battery monitor. Watch the the SG on your batteries. More than likely you will need to increase the absorb time (to max probably if your off grid) and up the absorb voltage.

    You can also use the system in a grid support mode with sell off. About 25% of your power will come from the grid all the time untill your battery voltage gets lower than what you set, then 100% of the power comes from the grid.

    It's a ballance between keeping battery life and paying for power. Why do you have your system?
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #10
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

    Thanks. Will do.
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #11
    Re: Xantrex XW 4548 connected to a battery bank. Can it be grid tied too?

    Thank you Jeff. I'll try to see what I can get in terms of a battery monitor.

    I did read about the grid support function and I'm trying to understand it better. If I use this function would it mean that I will be using my batteries for 75% of my connected load requirements and the other 25% will come from the grid?

    Since I also have an MPPT CC I take it to mean that the grid will charge my batteries in conjunction with the PV array I have connected or does it mean the grid will only supply 25% of my connected loads until my battery voltages go below what I've set in which case the grid will now supply 100% of my load requirements but still not charge the batteries?

    I have no need to sell electricity to my grid. Basically, I'd like then XW inverter charger to help charge my batteries when the sun conditions aren't too great and my batteries are not getting charged as efficiently and could use some help from the grid.

    I'm using my system to supply about 30-40 % of my load requirements and also as a backup for when the lights go out in my area which would be about 4-5 times a year.
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