Off grid system - why so many controls?

alyazalyaz Solar Expert Posts: 114 ✭✭✭
Still trying to make sense of things. Here's one of the areas that I find confusing...

Once I get my new controllers installed, our system will have:
1 Apollo controller running a string of panels;
1 Rogue controller running another string of panels;
and then the inverter/charger (with a Magnum remote control).

All three devices (both controllers and the Magnum remote (inverter / charger) seem to allow you to set parameters - (batteries, time to charge, equalization etc.)

So, for example, are the equalization settings on the controllers specific to equalizing the batteries from the charge coming in from the panels and is the magnum remote (inverter/charger) specific to just the generator charging? And with two controllers does one override the other or do they operate independently?

I'm not understanding what seems to be an overlap of parameter settings/charging/equalization settings due to the three devices... hope that makes sense.
3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Off grid system - why so many controls?

    Welcome to the almost totally insane world of non-integrated system components. :p

    Here's an example of a perfect world:
    Two Outback FM60 charge controllers and one FX3524 connected via a four-port HUB to a MATE programming control. Push the buttons on the MATE and set the parameters for everything. Both charge controllers and inverter will agree on charge set points, equalization time, battery temperature, et cetera.

    Now back to the unreal reality of two charge controllers and one inverter all from different manufacturers that have no way of communicating with each other. You can call it chaos.

    So what happens? Each tries to charge the batteries according to its own parameters, including any temperature sensing. How well does it work? Whichever has the highest V point settings "wins".

    In other words, once one controller has pushed the Absorb Voltage to its set level of 14.8, the other controller that has a set point of 14.4 decides the battery is fully charged and doesn't really add much to the mix. Equalization time is the same problem: even if all agree on the Voltage, the one with the longest time will try to keep the EQ cycle going until its clock runs out.

    If you can get these numbers set fairly close to one another, it won't make much difference. Sometimes it means there won't be enough power to perform a particular function (might drop out of Absorb when a load comes on because only one array is handling the job) but most of the power is needed for Bulk where there is no particular Voltage involved. Sometimes the difference can be great enough to trigger fault readings in one of the other components (EQ of 15.1 from a controller which the inverter might see as "over Voltage" for example).

    Mostly this is one of the problems of trying to expand a small system into a larger one.
    Usually you pick a "main charge source" (i.e. charge controller as opposed to inverter/charger) with the largest power potential and try to configure to that; the smaller array (and/or inverter/charger) simply "helping out" during bulk charging.

    When they can't "talk" to each other, all you can do is set them close as possible to one another and hope the battery temperature changes don't throw things too far off.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Off grid system - why so many controls?
    Usually you pick a "main charge source" (i.e. charge controller as opposed to inverter/charger) with the largest power potential and try to configure to that; the smaller array (and/or inverter/charger) simply "helping out" during bulk charging.

    That's the way I run my system. The MX-60 supplied from the solar panels looks after EQ etc. The TS controller is just the "assistant". It's programed to never EQ, and it's absorb voltage is set a wee bit below that of the MX. Thus during daylight hours the MX is the "main man", but at night when the MX goes to sleep, the voltages drop slightly and the assistant supplied from hydro becomes the main man, and all is well with the world. :D
  • alyazalyaz Solar Expert Posts: 114 ✭✭✭
    Re: Off grid system - why so many controls?
    That's the way I run my system. The MX-60 supplied from the solar panels looks after EQ etc. The TS controller is just the "assistant". It's programed to never EQ, and it's absorb voltage is set a wee bit below that of the MX. Thus during daylight hours the MX is the "main man", but at night when the MX goes to sleep, the voltages drop slightly and the assistant supplied from hydro becomes the main man, and all is well with the world. :D

    ahhhh... thanks guys... :D
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
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