Xantrex sw

kakiwaki

Hi there I currently have 8 sw units that need to be repaired. The 4 have been repaired but now I am faced with 3 units that have the same problem.

When I supply the AC1 or AC2 voltage the relays click but will not hold closed.
When the unit Inverts only on the batteries it works fine but when the AC breaker closes the unit trips out.

PLEASE HELP ME

RCinFLA

Re: Xantrex sw

Are you trying to repair them yourself?

Sounds like maybe one of the three transformer drivers is out. Look at waveform when on inverter to see if it looks like a sinewave or step choppy.

MOSFET's are 80 v, 40 amp devices.

SW units are not the easiest construction to troubleshoot. Very cramped in MOSFET driver area.

kakiwaki

Re: Xantrex sw

Yes I am repairing them my self.
I fixed the other 4 Inverters but this one is giving me trouble.

Transformer driver ????? U mean the mosfets inside the heat sink ?????

I did try using a mosfet bank from another Inverter and it worked fine .............
So you suggest the problem is not on the RELAY BOARD ?????

RCinFLA

Re: Xantrex sw

kakiwaki wrote: »

Yes I am repairing them my self.
I fixed the other 4 Inverters but this one is giving me trouble.

Transformer driver ????? U mean the mosfets inside the heat sink ?????

I did try using a mosfet bank from another Inverter and it worked fine .............
So you suggest the problem is not on the RELAY BOARD ?????

Based on the limited info you provided I would say it is not the relay board.

The unit will disconnect from mains if there is excessive current flow output of the inverter.

When one of the three transformers are not driven properly due to blown out MOSFET's on its primary side H-bridge the output waveform cannot build the stepped sinewave. Since it cannot match the input sinewave main AC there is large current overloads.

Small transformer puts out -15v, 0v ,+15v (approximately)
Midsize transformer puts out -45, 0v , +45v
Large transformer puts out -135v, 0v, +135v

This yields 27 possible combinations to build the stepped sinewave. When one of the three goes out there is a hole in the steps yielding a very choppy output waveform.

The control sensing will open relay.

Sounds like you already proved this if you say you swapped out the MOSFET board and it works.

kakiwaki

Re: Xantrex sw

Let me try give some detailed info.

I have measured the transformers. They all have outputs.

You stated that "The control sensing will open relay." The relay does not even close to begin with. It tries but it does not click closed.

Practically it looks like for some reason it does not accept the AC1 or AC2 voltage.

Where or what does the sensing ?

Thanx once again

RCinFLA

Re: Xantrex sw

There are voltage and current sensing on the relay power board which is fed to the main control processor board.

There are senses on each of two ACin ports and Inverter port. See attached schematic of power control board. The three small voltage sense transformers put out about 13.8 vac for a 120 vac input. These three small transformers have hair fine wire primary windings that a vunerable to lightning surges on ACin lines. No high voltages are sent to main processor board.

The main control processor board, on top of inverter, takes the inputs from the small sense transformer pickups, feeds them through an analog to digital converter so the processor can make decisions on what to do.

When ACin first shows up, the voltage/phase will be sensed and main processor will adjust inverter phase and voltage to match. When voltage and phase finally matches the AC1in or AC2in input the power relay will close putting the ACin in parallel with the inverter.

If voltage of ACin is out of spec it will not engage the relay. If the AC2in phase is wobbling around a little, as sometimes happens with a generator, the control board may not be able to get a lock on the ACin phase.

When green light goes solid it means control board has locked on input and power relay is closed putting ACin and inverter in direct parallel connection.

For trouble shooting, while on inverter, no AC input, read ACout with true RMS voltage, or better yet, look at output waveform with a scope.

You can not rely on just reading a voltage on any one of the three power transformers as their secondaries are connected in series so one can induce a voltage on another.

The primaries have three separate H-Bridge MOSFET drivers, transformer primary depending if model is 24vdc or 48vdc, will present forward battery voltage, short across primary, or inverse battery voltage across primary. If one leg of the four legs of an H-bridge is open you will get one polarity but not the swap polarity on that transformer.

The principle of stacking three transformer secondaries in series relies on tight primary to secondary coupling on transformer (low leakage inductance). When primary is shorted, that transformer secondary looks almost like a short. Actually there will be some small resistance and couple of mH of inductance. In this way it uses the three transformers secondary outputs to build an approximate sinewave. With nominal battery voltage and nominal A.C. voltage, 22 to 24 of the 27 possible combinations are used. It uses more steps as the battery voltage drops, or when AC input is higher then 120 vac. It uses less steps when battery voltage is high or ACin is low.

'Pappa Bear' is chopped at 60 Hz. 'Momma Bear' and 'Baby Bear' are chopped at higher frequency. I forgot exact numbers but I think I remember 'Baby Bear' changes polarity at up to 240 Hz.

Since the physical layout and connections are somewhat cramped be careful while trouble shooting. It will knock you on your butt if you are not very careful.

kakiwaki

Re: Xantrex sw

No you have gone and lost me ...........................

The green light does not go solid. It keeps on flashing while it tries to decide what to do with the input. So I guess there is a problem on the Main Control Board.

Any Idea what IC's I should look at............... I have changed all the Microprocessors as I have new ones but still no luck.

RCinFLA

Re: Xantrex sw

You need to look at waveform on ACout.

kakiwaki

Re: Xantrex sw

Thanx I have already checked them. I even have a repair manual and I did see the correct waves.

The problem is im not sure which board is faulty if its the AC or the Control Board


I am so so angry

boB

Re: Xantrex sw

kakiwaki wrote: »

I did try using a mosfet bank from another Inverter and it worked fine .............

That kind of says that it is the mosfet assembly.

One thing that would often break on those were simply the thermistor that senses the heatsink temperature. They look kinda like a little glass diode and just solder into the FET PCB.

If you have good waveforms on all 3 sections of the other units, them maybe it's that thermistor.

Another common thing that used to go wrong with those inverters was the AC input voltage sense transformer. Since they are wound with "hair wire", they would break. Doesn't sound like that is your problem but just in case you do see that problem it could save you some
time.

I'd check that thermistor. Easy to fix and replace as I remember.

Happy Christmas & Merry new year !
boB

kakiwaki

Re: Xantrex sw

Bob thanx for the GREAT HINT bud I really really hope this is this the issue I have checked every single IC on the damn control board and also checked the damn sense tranis on the AC Board. In fact the fuse was blown on the fet board so mayb/ i hope the thermistor is gone.

I will test it.

Merry Xmas to you to and Happy New Year


:D8):p:roll:

boB

Re: Xantrex sw

kakiwaki wrote: »

Bob thanx for the GREAT HINT bud I really really hope this is this the issue I have checked every single IC on the damn control board and also checked the damn sense tranis on the AC Board. In fact the fuse was blown on the fet board so mayb/ i hope the thermistor is gone.

I will test it.

Merry Xmas to you to and Happy New Year


:D8):p:roll:

Well, if the fuse on the FET assembly is blown, I don't really know why the inverter would give you a good waveform. Can't remember where that fuse went exactly, but I think it was for the FET drive circuit ? That fuse was put in there only because ETL wanted it put in there as far as I remember.

Good luck and a Happy Christmas 2 U 2 !

boB

kakiwaki

Re: Xantrex sw

Have not checked the thermistor yet ..................... but just one thing troubling me

Would the Unit be Inverting corectly if the thermistor was blown ..........!!!!!!!!

The fuse that was blown did now allow the Inverter to power up. I have changed the fuse. I will now test to see if the thermistor is correct.

Like I said the Inverter starts playing up when I connect AC to it ........

Will let you know what happens. If u have any other ideas please let me know

boB

Re: Xantrex sw

OK, you said the SW is inverting OK and it stops working when you plug in the generator or grid ??

If so, then maybe it's that input voltage sense transformer ?

But then, if it was the xformer, I don't know why it would even try to into charge mode and go out of invert mode. Does the display show the input voltage ?
Does it say AC IN GOOD ?

What was the problem again ?

boB

kakiwaki

Re: Xantrex sw

Ok heres how it goes ........

It Inverts 100%. Then I plug in the AC1 or AC2 after 30 seconds when the relay is supposed to engadge, boom nothing happens. The AC led keep on flashing and then the error led comes on.

When I try go from Inverting to charge mode its the same .............. with the AC1 or AC2 puged in it will not charge.


I meassured the voltage sense transformer, I get the correct ohms that the service maunal says.

The AC voltage IN is displayed on the Unit as it trys to stabilise on 230 then it crashes, and then tries to re-sync.

boB

Re: Xantrex sw

Ahhh... OK, Do you hear the transfer relay click after the AC input is on for those first 30 seconds or so ?

~maybe~ it's the relay or relay driver transistor ?? But you already went over the relay board, so I vote for the driver or cable.

Maybe the driver is on that power board ? I wouldn't have thought it would be there but it's been so long that I'm not sure of much of anything I know about this stuff.
boB

RCinFLA

Re: Xantrex sw

What is the error readout.

ERROR CAUSES (5) MENU HEADING (yes/no readout)

Over Current
Transformer overtemp
Heatsink overtemp
AC source wired to output (this is error if relay contacts are welded together)
Generator sync (for AC2in)
Inverter breaker tripped

I would think the temp errors would shut down inverter with or without ACin.

If sense transformer is open it thinks there is no AC input. You will not get error for no ACin.

boB

Re: Xantrex sw

So, does this service manual have a schematic and parts layout for the SW ??

boB

kakiwaki

Re: Xantrex sw

Hey guys the crazy thing is, yes the service manual has schematics and layouts of all the baords.........................

Bob ---- I have replaced the damn relay transistor and still nothing, and yes I do hear the click after 30 seconds. The relay tries to move closed and nothing happens.
The relay is not welded closed as when I supply 12v to it it opens & closes correctly and when I measure the contacts they are correct.
Not so sure about the cable as I have 4 Inverters with the same problem. According to me its something very very simple and stupid that has gone wrong with them.

RCinFLA ---- The damn error read out says NOFINK !!!!!! It states NO NO NO NO to all the errors. I agreee with u the temp switch.
I have meassured the sense transformers out of cicuit and they looked fine.

GUYS I AM TOTALY LOST !!!!!!!!!!!!!!!
I have no f#@%ing clue as to what to test next, I feel useless.

Ralph Day

Re: Xantrex sw

Useless??? Most of us just look at the pretty lights flashing on the pretty boxes on the wall and cross our fingers!:p

Sure hope it's something simple.

Ralph

boB

Re: Xantrex sw

kakiwaki wrote: »

Hey guys the crazy thing is, yes the service manual has schematics and layouts of all the baords.........................

Bob ---- I have replaced the damn relay transistor and still nothing, and yes I do hear the click after 30 seconds. The relay tries to move closed and nothing happens.
The relay is not welded closed as when I supply 12v to it it opens & closes correctly and when I measure the contacts they are correct.
Not so sure about the cable as I have 4 Inverters with the same problem. According to me its something very very simple and stupid that has gone wrong with them.

RCinFLA ---- The damn error read out says NOFINK !!!!!! It states NO NO NO NO to all the errors. I agreee with u the temp switch.
I have meassured the sense transformers out of cicuit and they looked fine.

GUYS I AM TOTALY LOST !!!!!!!!!!!!!!!
I have no f#@%ing clue as to what to test next, I feel useless.

Try measuring the voltage at the AC output to make sure that relay is transfering input to output. Then measure the voltage at the end wires of the 3 transformers wired in series to make sure that voltage is ending up there too.

You did say that changing the power board assembly fixes the problem, right ?
And it inverts fine ? (Sorry, I'll go look at the previous posts)

We'll figure this out. I better dig out my schematic.

boB

kakiwaki

Re: Xantrex sw

The voltage is correct at the AC output.
And I also get the 220-230 at the Transformers, but the wierd part is that the 220 coming out of the transformers........
When I have it disconected from the AC board it works OK When its conected I get the error, the two wires coming from the trans, I remove one of them and it works OK.

So maybe it has something to do with sensing ?????? WHO KNOWS .........................


I did change a power board and it worked fine buttttttttttttttttttttttttt.
My one Inverter that was OK broke from me changing boards around.
I had 2 good INVERTERS and they stoped working after I swaped boards.

CAN IT BE DUE TO STATIC ????

boB

Re: Xantrex sw

kakiwaki wrote: »

CAN IT BE DUE TO STATIC ????

Probably not... UNLESS you are noticing a LOT of BIG sparks ! Then, maybe.

It probably stopped working just because of bad connections. Maybe that's it ?!!?

Have you tried banging on things ? Tapping with an insulated something-or-another ?? If there is an intermittent connection, that might help to find it.

Or, did we already go there ? That works well for me in many cases.
boB

kakiwaki

Re: Xantrex sw

bob wrote: »

probably not... Unless you are noticing a lot of big sparks ! Then, maybe.

It probably stopped working just because of bad connections. Maybe that's it ?!!?

Have you tried banging on things ? Tapping with an insulated something-or-another ?? If there is an intermittent connection, that might help to find it.

Or, did we already go there ? That works well for me in many cases.
Bob

ok well ill start banging it from tommorow, but please try think of anythinh else

Dave Angelini

Re: Xantrex sw

kakiwaki wrote: »

ok well ill start banging it from tommorow, but please try think of anythinh else

Going back to the first post you said the unit inverts fine. Prove that it does by load testing it. Turn on a 1500 watt heater from low heat to medium heat to high heat and make sure you do not get errors or shutdowns. Good Luck!

kakiwaki

Re: Xantrex sw

Dave Sparks wrote: »

Going back to the first post you said the unit inverts fine. Prove that it does by load testing it. Turn on a 1500 watt heater from low heat to medium heat to high heat and make sure you do not get errors or shutdowns. Good Luck!

Hi Dave, thanx for the info funny enough the Inverter works super under load. Ive given up to 3000 watts. It inverts while on a battery bank but like I said when I connect it to a grid voltage on AC1 or AC2, the trouble starts ..................................

The relay does its half click and wont stay closed and then the inverter locks ( ERROR LED IS NOW ON )

boB

Re: Xantrex sw

kakiwaki wrote: »

Hi Dave, thanx for the info funny enough the Inverter works super under load. Ive given up to 3000 watts. It inverts while on a battery bank but like I said when I connect it to a grid voltage on AC1 or AC2, the trouble starts ..................................

The relay does its half click and wont stay closed and then the inverter locks ( ERROR LED IS NOW ON )

Do you have a scope there ? Maybe the AC input voltage is dropping as soon as it connects for some reason ? You could look at the output with that scope and see what gives, if anything. This would also verify that when it transfers to grid, that the waveforms are synched up.

boB

Dave Angelini

Re: Xantrex sw

Other things I can think of that may be posted... Look at the frequency of the inverter on the "meters screen" before and after you connect to the grid. You do have the right frequency SW for your area right?

With all the inverters you have, why can't you start taking suspect parts out and testing them in a good one?

The load test with a 3 speed heater test was to make sure the inverter works at various power levels. Low, medium, and high. I was told by Bob's buddy (maybe?)Jeff Everette now doing batteries for electric cars that it was a good way to field test an SW to make sure the 3 different inverters were interacting correctly.

Also look at the waveform as has been suggested during the relay changeover.

Make a new years resolution to go solar and in your location you might not need a generator:cool:

kakiwaki

Re: Xantrex sw

The frequency I did not pay much attention to, I must be honest but yes it is the correct SW for my area.

As for taking out good parts, been there done that got the T-Shirt. Thats whats getting me so so mad, I have 4 Inverters with exactly the same fault. I am going crazy.

About the waveforms on the relay change over, I dont get a relay change over. The error occurs just as the relay tries to close and then nothing.....................

As for the 3 stages of load testing, yes I have a TEST BENCH with globes at 500 watt intervals so I did do all 3 ( thanx 4 the tip ).

boB

Re: Xantrex sw

kakiwaki wrote: »

The frequency I did not pay much attention to, I must be honest but yes it is the correct SW for my area.

As for taking out good parts, been there done that got the T-Shirt. Thats whats getting me so so mad, I have 4 Inverters with exactly the same fault. I am going crazy.

About the waveforms on the relay change over, I dont get a relay change over. The error occurs just as the relay tries to close and then nothing.....................

As for the 3 stages of load testing, yes I have a TEST BENCH with globes at 500 watt intervals so I did do all 3 ( thanx 4 the tip ).

OK, I thought I heard that you can hear the relay click. If not, did you check the signal going to the relay drive transistor ? I think you said you checked the transistor itself, but it might be that there is only a very short pulse getting there ?

I need to get out a schematic of the FET board since that is what you say makes it work again... changing out that board that is. (right ?)

boB

kakiwaki

Re: Xantrex sw

boB wrote: »

OK, I thought I heard that you can hear the relay click. If not, did you check the signal going to the relay drive transistor ? I think you said you checked the transistor itself, but it might be that there is only a very short pulse getting there ?

I need to get out a schematic of the FET board since that is what you say makes it work again... changing out that board that is. (right ?)

boB

Nope the signal I did not check. But I changed the IC that I think sends the signal and the transistor too ........I have all the schematics I can send them to you.

I said the FET Board seen as when I had 1 working unit, if i remem correctly the control board was working in it.