[RE-wrenches] Outback IN AC Current Too High

[Tyrone Houck]

First things I would check:

1. Charge current(if its too high the combination of loads and charging
could easily explain the problem). If the loads plus charging exceeds the
programmed limit for any amount of time it will throw the "AC Current Too
High" error.

2. A motor or compressor load on it's way out or in combo with charging.
Also consider any heating/resistive load possibly pushing the equipment
beyond its surge capabilities.(consider in context of #1 above)

3. A loose connection increasing resistance on the AC(or even the DC) side.

4. Check firmware and or factory reset/reprogram the Mate3s(I would do this
anytime I used a previously installed unit on a new system).

Consider battery chemistry as well...this may be a relevant factor if
replacing lead acid with lithium...less likely to be the culprit but
definitely worth thinking about.

Hope these ideas help. Feel free to reach out here or off list if I an be
of any further assistance!

Sunny Regards,

Tyrone Houck
Oregon Solarworks LLC
CCB #204937 LRT #076
541-787-1366





On Sat, Feb 28, 2026, 9:14 AM Kristopher Schmid via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Hello fellow wrenches,
>
> I have a legacy grid tied outback system that is throwing an IN AC Current
> Too High error followed by an IN AC Current OK message very regularly.  I
> recently replaced the dead FX3648 with a new VFXR3648A.  The original
> system installer did not install a Mate.  The new inverter said that it
> required a Mate3S.  I was unable to source a new one at installation time
> (backordered), so I put in a used Mate3S that I had on the shelf.
>
> I found an old thread on the Outback User Forum from 2012 that mentions
> this issue, but it didn't seem to indicate a definitive solution.  It
> suggested that it was potentially a firmware issue.  I had the client try
> to ACK ALL in the events menu, but the inverter still showed a red error
> light along with the repetitive error beeping.  I also had the client
> verify that the Grid Input AC Limit matched the Grid Input breaker size (50
> A).
>
> This site is 2 hours drive and I am waiting on Wattsun engineering to
> provide a replacement azimuth motor solution for the tracker.  I would like
> to have a solution to this inverter issue in my back pocket when I make the
> trip to replace the tracker motor.
>
> Anyone know the current state of Outback Tech Support?
>
> Any help is greatly appreciated,
> Kris
>
>
> Shine On!
>
> Kris Schmid
> Legacy Solar, LLC
> 137 W 1st Ave
> <https://www.google.com/maps/search/137+W+1st+Ave+Luck,+WI+54853?entry=gmail&source=g>
> Luck, WI 54853
> <https://www.google.com/maps/search/137+W+1st+Ave+Luck,+WI+54853?entry=gmail&source=g>
> www.legacysolar.com
> 715-653-4295
> NABCEP Certified PV Installation Professional
> Licensed Wisconsin Master Electrician
> BSEE
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