MS4024PAE Magnum Inverter problems...

alyaz

A neighbor, who has the same inverter as us, has gone through two of them now, in the last several months... Both issues occurred when they were equalizing the batteries. The first one was apparently ruined by an overheat problem and the cables couldn't even be removed from the terminals as they were welded on. The second incident, just two days ago, (while he was equalizing) the inverter displayed a 'branch fault,' I believe they said. He's not getting much information back from the installer or from the supplier on it and he seems a little resistant to contact Magnum support as they weren't very helpful during the initial issue.

When his system has been working, it has been working fine. Anyway, the only anomaly I see on his system is that there is no DC disconnect/breaker. Could that be part of the problem during equalizing? Other ideas?

Thanks...

Vic

Re: MS4024PAE Magnum Inverter problems...

Hi alyaz,

Sorry to hear of the problems with Magnum inverters. At the least, all of the power electronic hardware should have some form of Over-current Protective Device on the inputs and outputs.

Circuit Breakers are the most conveinient. But Inverters of all things really do need a Fuse plus DC disconnect or better yet a breaker, especially on the DC side.

It is possible that the DC connections to the inverter were not tightened sufficiently to speced torque. This is very important with high current connections, because looseness can mean unnecessarily high resistance at the connections, with the high currents that inverter battery connections deal with even small resistance over time can cause high heat.

It is also possible that the lugs on the battery cables were not well crimped (at least not at the inverter end of the cables, perhaps). It would be good that someone competent check this. This is easily done when a working inverter is drawing or supplying high-ish currents, and a simple voltage drop measurement is made with a good DMM from end-to-end of these (and all battery cables while one is at it). Even a touch test with higher currents flowing for a few minutes can give an indication of crimp integrity.

EDIT: Looks like the recommended battery to inverter DC cables are 4/0 Cu at 90 C with 250 A breaker if cables 5 feet or less.

If there is no OCPD on the inverter DC side, this can be a fire hazard, and, to me the installer of such a system would be suspect, in my opinion.

Vic

alyaz

Re: MS4024PAE Magnum Inverter problems...

Thanks Vic.

Part deux to this scenario. A new Magnum inverter arrived today and a licensed electrician removed the old Magnum and put in the new Magnum inverter. The electrician checked the battery cable size and condition and then checked the cycles the gen was putting out and couldn't come up with any explanation why two Magnum inverters have toasted during equalizing. This leaves the neighbors pretty reluctant to ever try an equalization again.

Anyway, because the neighbors are good friends, I can't help but think about what went wrong with their last two Magnum inverters. If you will humor me, I will go back to what I see as the beginning of the problems with the inverters. When the first Magnum inverter was put in, it was installed by a local solar person. The inverter that was in place and which was replaced was a 110v inverter (I think it was an Xantrex). So when the neighbors ordered a new Magnum 110/220v inverter, the solar installer said he had to 'rewire' the Kubota Diesel Gen. Ever since this 'rewiring' of the generator occurred, it seems to me that the problems have started and persist...

Sooooo, is it possible that the rewire from Generator to inverter was wired incorrectly? Even though the electrician checked the cycles today, could he have missed the fact that the gen to inverter 110 to 220v rewire was done incorrectly? Is it possible that too many amps are now being put into the inverter? For example, could the neutral / ground have been miswired... and how likely is it the electrician wouldnt have picked up on it today? (If you recall there is no DC disconnect / breaker on their system). I know, long shot here...

Sorry, this is probably a pretty lame explanation or shot in the dark by someone that knows very little, but I can't help but think that the rewire from 110 t0 220v is the variable that went wrong...

All suggestions appreciated.

Vic

Re: MS4024PAE Magnum Inverter problems...

Hi alyaz,

Thanks for update.

First, as I read your last post, it seems that you are saying that there is NO DISCONNECT between the battery positive and the inverter. Then I do hope that there is a FUSE at the very least, as batteries store a lot of energy, and with large cables mucho heat can be developed in a small area in a short time. If there is no circuit breaker and no fuse, then the installer should be retired, and a COMPETENT electrician or installer found to check ALL of the system wiring.

Normally, an inverter/charger dictates the amount of current needed for inverting and charging. The generator should not be able to force more current into the inverter than it demands.

There could be a problem if the generator has a safety ground - to- neutral connection, as there should be only one such connection, and it should be in the main panel. Typically, larger gensets without built-in AC outlets has no ground - neutral connection, and those with AC outlets has this safety connection ... this is an older "rule", and one never knows just what the manufacturer/integrator actually did. More than one such N - G connection causes a ground loop, which can cause some unusual/bizarre behavior in power systems. This should be checked.

Regarding rewiring for a Split-Phase inverter like the Magnum, this should have required adding one extra hot AC cable, an appropriate circuit breaker, and perhaps a new "Bypass Switch" it the AC panel has this function.

Realize that you are dealing with second/third (etc) information, but the cables from the Magnum to the batteries should be 4/0, with a 250 A circuit breaker, this wire size should be confirmed. All of the DC cable connections should be re-torqued, including every battery connection point, by someone that knows what they are doing.

Regarding the problems occurring during EQ, this should not be a real issue, as the Magnum should control the DC current and protect itself from damage. However, for battery health (as you probably agree), an EQ should be done when the batteries have gone through a complete charge cycle. If this is not done, the batteries COULD experience excessive charging currents as the charge voltage rises above the nominal Absorb voltage. But, still, this should not damage an inverter, as it should always protect itself from excessive current.

It is possible that there could be a poor connection in the battery cables that might possibly create a problem for the inverter, but this is just guessing.

And again, each battery cable and the cables connecting the batteries to the inverter should be checked for voltage drop while the inverter is drawing or supplying significant current (running a portable AC heater for example, or during Bulk charge. None of these voltage drops should exceed 10 - 20 millivolts at 40 - 50 Amps. Enough for now, Good Luck, Vic

niel

Re: MS4024PAE Magnum Inverter problems...

i wouldn't rule out the possibility of the genny being rewired wrong. makes me wonder why the need to rewire in the first place too.

alyaz

Re: MS4024PAE Magnum Inverter problems...

Thanks guys. I will pass the info on to them. I consider myself fortunate, having been provided information regarding my system here and basically telling the installer what and how it was to be done. Yes the couple of installers available to us should be retired, or better yet, never have began dabbling in solar.

Blackcherry04

Re: MS4024PAE Magnum Inverter problems...

Anyone that has to go behind some Installers and clean up their messes can tell you what a pain it is. Do it right Once is a lot easier than going back. The problem is if you don't correct it all it will cascade into another problem.

I remover 32 of these lugs from a system this week. The 4/0 cables were great, the crimps were great. The Installer used lugs with 1/2 inch holes on 5/16 posts. Look at the contact patch from the nut and how it overheated. Most of them had melted the heat shrink off. You can get away with stuff like this on low amps, but not 300 amps. A system may look great, doesn't mean it is.

Attachment not found.

Vic

Re: MS4024PAE Magnum Inverter problems...

alyaz wrote: »

... The inverter that was in place and which was replaced was a 110v inverter (I think it was an Xantrex). So when the neighbors ordered a new Magnum 110/220v inverter, the solar installer said he had to 'rewire' the Kubota Diesel Gen. Ever since this 'rewiring' of the generator occurred, it seems to me that the problems have started and persist...

Sooooo, is it possible that the rewire from Generator to inverter was wired incorrectly? Even though the electrician checked the cycles today, could he have missed the fact that the gen to inverter 110 to 220v rewire was done incorrectly? Is it possible that too many amps are now being put into the inverter? ...

Hi niel,

Seemed to me that if the previous inverter installed at this site might have only had one how AC cable, as that is all that the inverter could deal with. Some added AC cable would probably have been required, at least to the new Magnum inverter which is Split-Phase.

We all are doing quite a lot of guessing, at least I am. Best of luck alyaz. Vic

niel

Re: MS4024PAE Magnum Inverter problems...

vic,
agreed on the guessing and so many mouths away as translations can get jumbled. it is still possible the rewire is wrong and i can't see what the generator's panel looks like to know specifically what would've been needed as many gennys have a 240 outlet in addition to 120. could've been just a new plug and wire to go to the genny. don't know.

alyaz

Re: MS4024PAE Magnum Inverter problems...

i did check the cables today. 4/0 to the inverter and 1/0 between batteries. no heat at all to the touch when generator had been running for a half hour or so...

the gen to inverter is hard wired, and i don't know enough to frick around with that stuff...

anyway do you guys have any suggestions on how i can get some basic solar install qualifications? i know this isn't the proper place to post this, but i would appreciate your advice. i contacted a company based in Toronto but they have dropped off the face of the earth after numerous emails...

regards...

westbranch

Re: MS4024PAE Magnum Inverter problems...

don't know if these will help

https://www.coursera.org/courses?orderby=upcoming&search=electric&lngs=en

embajador

Re: MS4024PAE Magnum Inverter problems...

Magnum uses inferior components which could cause all of these problems. My inverter failed due to a defective fan, causing the unit to overheat. I buy the same cheap fan on eBay (new) for $1.00. Magnum charges its distributors $25.00 for the same fan. Magnum should be more worried about producing a quality product than saving a few bucks by buying defective components.

Zardiw

Hey....not to hijack the thread or anything......but is there any way to hook the inverter to a network/computer.....I mean is there any software out there?

mcgivor

What inverter, make, model etc