Magnum MS4024 Lost Its Mind

mcnutt13579

We have a customer with a MS4024 (not AE or PAE) that sat powered down all winter.  When they powered it up it never worked. 

We noted on the ME-ARC the following fault codes repeated, 9 in total: Overcurrent and Overload.  It would not even try to invert.  No load connected to the outputs at any time.

After repeated power cycles, fault codes, etc. we got it to try to come on with the 15 second press.  Then it began throwing faults for Internal Bridge and High Battery.  Interesting to note that on all the faults except High Battery it logged the actual battery voltage but on the HB fault it logged 40.3V which was in error because I could see battery voltage the whole time and it was always near 30, never higher.

So in my mind this fault could go 2 ways, either the main brain has lost its mind or there are issues with the power board, any advice from someone who has repaired these before?

Dave Angelini

Did it have surge protection? Offgrid lightning and just as serious some of the spikes that come out of the grid can be just as bad.
Without surge protection you may never know and magnum would have to pay to do a full tear apart failure analysis. They probably would give you a new one or a credit before spending on an FA, if you still had warranty. You should still call them.

Estragon

After a winter of idle, I have to wonder if a critter met its maker when they powered up. Has anyone taken the cover off to see?

BB.

The other would be condensation or water leak in the building.

I have also seen water follow wiring into boxes, or even conduit "springs".

Check wiring and terminals (retorque binding screws, check for critters chewing insulation).

Bill

mcnutt13579

Further look.  Power board has a bunch of burned parts.  Nothing visibly wrong with the brain board.  A few spiders but not much contamination.  All points to blown power board only except the high battery error.  That is concerning, but we shall see.

mike95490

Generally, 30V is bad on a 24V system, unless you are in an EQ cycle.

And with a load of burnt parts, you likely found some lightning over the winter. 

mcnutt13579

I wasn't the one who set up the charge controller but these are L16s, bulk charge 2.45 ± 0.05 so 2.5 * 12 = 30.0

In any case the inverter was complaining about high battery but logging 40+ volts when it did and that never happened.

BB.

Poor electrical connections can cause real over voltage problems (solar charge controllers can over volt if not solidly wired to the battery bank). Obviously, wet/dusty circuit boards can allow higher voltages to flow to sensitive low voltage circuits.

Or, a part/mfg. fault can cause both "high and low" FETs to turn on at the same time--And create a short circuit current flow through the FETs.

Without a failure analysis--Just guesses at this point (and not all FAs give usable answers).

-Bill

Dave Angelini

Another reason (guessing) that a logging program for faults and warnings like Schneider and Outback offer. This is especially valuable when there is not a human there (not the OP) to take a peak now and then. already did the SPD warning....FRIDAY !

mcnutt13579

I am no fan of Magnum.  Seems like the bargain basement product.  But the owner did call and complain and apparently they repaired it as if it was under warranty (it was 6 months to a year outside) and he put it back himself.  They are better than some junk out there for sure.