A strange thing happened to my Axpert, it’s burning rs232 cards when ever i plug serial to computer 

 

What could be the problem with the inverter 

Edited April 3, 20215 yr by roosterzw

7 hours ago, roosterzw said:

Axpert, it’s burning rs232 cards when ever i plug serial to computer 

The RS-232 port is supposed to be isolated from the rest of the computer, but I suspect that the computer side is earthed to the metalwork / earth connections.

Your computer is probably earthed, unless it's a laptop that isn't charging at present (depending on the charger). So I'd say you have different earth potentials.

Use a multimeter, on both DC and AC voltage ranges, to check the difference between metal parts of both. My guess is you'll see over 100 VAC. If so, check each against a known earth, such as a metal tap.

It's possible that you have a neutral to earth linkage problem, such that some of the neutral current is flowing through your RS-232's earth wire. But if it's actually destroying the cards (check the cables as well), then it's more likely that an earth is not connected somewhere, and you're getting roughly half the mains voltage on one side or the other via the EMI capacitors (one from active to earth, another from neutral to earth), and there is enough energy in those capacitors (usually only 1 nF or so) to destroy whatever electronics happens to connect first.

i’m using a laptop and it not on charger 

9 minutes ago, roosterzw said:

i’m using a laptop

That's unusual then. How are you determining that the "rs232 card" (I assume you mean the communications card inside the inverter) is "burning"? Physical flames? Burning smell? Just a lack of operation?

There are plenty of ways that a communications board can appear not to be working.

Edit: and are you using the correct cables? It should be the supplied RJ-45 to D9 cable in series with a USB to serial adapter, or a USB A to USB B cable. The RJ-45 connector in the inverter is NOT an ethernet port.

Edited April 4, 20215 yr by Coulomb

I assume you mean the communications card inside the inverter) is "burning"? Physical flames? Burning smell? 

 

They are actually burning 🔥, producing some smoke 

Had the same issue with a Axpert 7.2kw King I purchased recently, kept blowing the rs-232 usb adapters. I suspect the cable has the wrong pinouts or I used the rs-232 from my old 5kw Axpert. If by any chance someone has the pinout for the 7.2KW Axpert I'd really appreciate it, I'll make a new cable, just wanted to upgrade the firmware. I tried the following pin outs with no success: 

RJ45 - DB9 female

1  -> 2 (TXD)

2 -> 3 (RXD)

8 -> 5 (GND)

This is really weird. As far as I know, the above is the correct pinout for the RJ-45 to RS-232 cable on all models.

The comms boards are all isolated, so it should not be any sort of earthing problem.

The comms boards (different to the removable display in the Kings etc) do have a slight tendency to melt the transformer; there was a photo posted recently. Perhaps it's just hanging together by a thread and actually using it pushes it to total failure. @roosterzw, you might be able to get it replaced under warranty, or buy a replacement board from your supplier, or fit a third party board from Ali Express or the like.

I found out some more info with regards to the RJ45-RS232 cable, pin 4 carries +12V. This is what has been blowing the adapters and could also cause problems with burning your card

RJ45 Pin4 -> DB9 Pin6  +12V

So there are two types of cables, one powered and the other not. Just check if that pin is populated.

Edited August 7, 20215 yr by Not From Eskom

On 2021/08/08 at 8:32 AM, Not From Eskom said:

RJ45 Pin4 -> DB9 Pin6  +12V

DB9 pin 6 is DSR, Data Set Ready. I would leave that unconnected.

On older models, +12 V appeared on pin 7 or the RJ-45. Nothing like consistency.

Very interesting, so much for standards as you say 😂