Good day members .
Im at it again trying to repair an axpert inverter . Please kindly advise i am getting error 57 on it .
I have a spare control board .. the one that sits on the left hand side that connects to the can comm, and screen. 
i replace the board and the inverter powers up and then immediately goes into a power cycle clicking non stop screen flickers and three led lights flashing on the front .

If i place the old board back in i get error 57 .

Checked the pre stage 3300 uf capacitors and are measuring in spec. 63v

also checked the output and removed them and they measure with in spec.

Checked the 470uf 500v units they also seem to be okay ...

Not sure where to go next ... and hate to sit and go through the whole service manual . But will do it if no one else has come across this before ..

thank you in advance ps i have tried this unit off battery only . No ac connected no AC output connected ..fans spin up too ..

11 hours ago, Zimnismoboy34 said:

 i am getting error 57 on it ... and hate to sit and go through the whole service manual .

Since error 57 is "current sensor failed", perhaps check the current sensors? That's the LEM and the current transformer. Also check the 47Ω burden resistor under the board near the current transformer. It's also possible that an op-amp on the control board has failed.

It sounds like your spare control board may not be working, or is for a different model.

thanks for that appreciate it the most knowledgeable man on the forums and your advice is always welcomed .. Will check those out . But the inverters are the same model . Model number 5KVA-PAR-A 5000va/4000w with a solar charge controller 50amp voc 105v ..

presume those are TX7 and u21 ? for the current sensor

2 hours ago, Zimnismoboy34 said:

presume those are TX7 and u21 ? for the current sensor

On mine, TX7 is a driver transformer. The current transformers on this one are marked CT1 and HCT1 (the blue LEM).

hmmm negative i dont have that hence i assumed that tx1 would be what i would be looking at ... i have attached a pic hopefully can clarify why my board is different probably much older ..or a good copy .

5 hours ago, Zimnismoboy34 said:

negative i dont have that hence i assumed that tx1 

You have CT1, check the burden resistor under that. Your model might have a shunt resistor instead of the LEM. I don't know if that could cause error 57 or not.

Ok traced the current sensing resistor wires to a ic u21 which actually says OP07 under neath . changed this out and no change . so must be something else in the circuit . I am unsure of the burden resistors you speak of under CT1 i see r199 un populated and r200 47R0 and r201 47R0 i did however have a chance to verify that all control boards and functional and working correctly . So the other symptom of the inverter trying to power on with the three LED and LCD flashing or pulsating non stop is some how tied into the main board fault . Not sure where else to check .

23 hours ago, Zimnismoboy34 said:

 I am unsure of the burden resistors you speak of under CT1 i see r199 un populated and r200 47R0 and r201 47R0

Ah. Those are in fact the burden resistor; they are in parallel across the secondary of the current transformer. Sorry, I didn't realise that there were two physical resistors in series. In circuit, they should measure around 21Ω.

correct 21.2 is the reading i get ... now very stumped .. something must be causing it but to dig deeper .. will do some more checking and testing . we zoning in on the fault which is good, thank you again for your help .

I have the same error 57 which has happened previously but it eventually went away and everything worked fine. Now it is back and I have had to connect the ac input to the output therefore bypassing the inverter in order to have grid power. Any updates on this issue? 

On 2020/09/15 at 7:09 AM, Rolf said:

I have the same error 57 which has happened previously but it eventually went away and everything worked fine

This sounds like your current sensors may need to be de-magnetised or replaced if it has happened and then recovered.

In this post I give some details on how I fixed Error 57.

 

 

On 2020/08/17 at 7:01 AM, Coulomb said:

Since error 57 is "current sensor failed", perhaps check the current sensors? That's the LEM and the current transformer. Also check the 47Ω burden resistor under the board near the current transformer. It's also possible that an op-amp on the control board has failed.

It sounds like your spare control board may not be working, or is for a different model.

How are you

I facing the same problem error 57, you mentioned many points to trace this error.

I want to ask you some questions

1_How to demagnetize the CT?

2_the burden resistor 47 you said it should measure around 22 something

In Maine there is only one 47 burden resistor which measured 37! (In circuit) Is it ok?

3_the supply of OP07CP ic is it supposed to be symmetric -12&12 at the v1 and v2? Because in main the -12 which supplies for the 7912 is ok, but the v2 is 12.5! Is this difference (0.5v) cause the OP07CP failure!?

 

On 2022/01/27 at 3:44 PM, almothanna said:

1_How to demagnetize the CT?

I would use an old tape recorder head demagnetiser. I have no idea if you can still buy those. Otherwise, fabricate some sort of electromagnet, connect it to low voltage AC (say 3 VAC if possible), and slowly sweep the transformer core, moving towards and away from the core as you go. It's especially important to move away slowly from the core.

On 2022/01/27 at 3:44 PM, almothanna said:

2_the burden resistor 47 you said it should measure around 22 something

In Maine there is only one 47 burden resistor which measured 37! (In circuit) Is it ok?

It seems highly likely to me that the current transformer secondary is open circuit. The primary should be only a few turns of copper tape, the secondary should have more turns but I suspect it should still have a resistance well under 10 Ω. Unfortunately, if that's the case, it will be very difficult to repair the transformer or to find a replacement.

On 2022/01/27 at 3:44 PM, almothanna said:

3_the supply of OP07CP ic is it supposed to be symmetric -12&12 at the v1 and v2? Because in main the -12 which supplies for the 7912 is ok, but the v2 is 12.5! Is this difference (0.5v) cause the OP07CP failure!?

I think that 12.5 V is just OK; usually regulator chips are ±5%, which would be ±0.6 V. I can't see how any failure of the op-amp could cause the supply rail to increase in voltage. If you're asking whether 24.5 V could be too high for the op-amp, I don't believe so. I'd start with the current transformer. Remove the 47Ω burden resistor first, and measure the resistance of it separately (and the winding resistance; the op-amp will not load it significantly).

On 2022/01/28 at 11:26 AM, Coulomb said:

I would use an old tape recorder head demagnetiser. I have no idea if you can still buy those. Otherwise, fabricate some sort of electromagnet, connect it to low voltage AC (say 3 VAC if possible), and slowly sweep the transformer core, moving towards and away from the core as you go. It's especially important to move away slowly from the core.

It seems highly likely to me that the current transformer secondary is open circuit. The primary should be only a few turns of copper tape, the secondary should have more turns but I suspect it should still have a resistance well under 10 Ω. Unfortunately, if that's the case, it will be very difficult to repair the transformer or to find a replacement.

I think that 12.5 V is just OK; usually regulator chips are ±5%, which would be ±0.6 V. I can't see how any failure of the op-amp could cause the supply rail to increase in voltage. If you're asking whether 24.5 V could be too high for the op-amp, I don't believe so. I'd start with the current transformer. Remove the 47Ω burden resistor first, and measure the resistance of it separately (and the winding resistance; the op-amp will not load it significantly).

Thanks for your valuable reply I appreciate it..

First thing I did removed out the 47 burden resistor, it's measured 100% correct! and i measure the CT secondary internal resistance it reading 175 Ohm  (without the 47 resistor) is this internal resistance is ok for this CT!?

One more thing maybe you didn't got my point about the supply of OP07CP, as you know it has two supply point V1&V2 one is negative the other one is positive, in mine the negative supply coming to the pin number 4 is -12 exactly, but the positive supply which coming to the pin number 7 is +12.5!

My question is this difference 0.5V between the two supply points could cause OP07CP failure or not!?

10 hours ago, almothanna said:

i measure the CT secondary internal resistance it reading 175 Ohm  (without the 47 resistor) is this internal resistance is ok for this CT!?

I was surprised to measure 20.7Ω across the two 47Ω burden resistors on the 2013 board I have here. Doing the calculation, that brings the winding to 174Ω. I would have thought that it was a lot lower resistance than that, but it looks like yours is fine. [ Edit: sorry, too lazy to remove the two burden resistors. ]

10 hours ago, almothanna said:

is this difference 0.5V between the two supply points could cause OP07CP failure or not!?

I don't expect that difference to be a problem, either operationally, or to cause a failure.

Edited February 1, 20224 yr by Coulomb