APC UPS 200XL

[Anonymous user]

Please guys,

I have this APC UPS 200XL that keeps showing overload and long beep with no load on it. This actually started after I fixed the initial issue (blowing any mosphet installed in it) it was having.

Thanks.

[Brad_C]

I replied in your other thread. Did you look at any of the things I suggested?

- Mosfet driver waveforms

- UPS configuration via serial console

- Acoustically identify source of high pitched sound

Check pin 6 of the ADC0838. That's the scaled voltage from the output power sensing circuit. It is scaled in hardware between 0 & 5V. That reports as power using the serial console, and it relies on the power scaling calibration constant in the uC being correct, which is why I suggested you look at the UPS configuration in the serial console. If the constant is screwed up it can lead the UPS to report high power when there is little to no load applied.

[Anonymous user]

I've not been able to check the drivers waveform and the serial console. But I checked the pin 6 of ADCADC0838 its producing 36v sending same 36v through D30 while D30 is producing the normal 5v from the other end which is getting me confused.

[Brad_C]

On 1/9/2017 7:10 PM, Samuel said:

But I checked the pin 6 of ADCADC0838 its producing 36v sending same 36v through D30 while D30 is producing the normal 5v from the other end which is getting me confused.

Something is terribly wrong with your measurement setup. Pin 6 of the ADC0838 is an input. It produces nothing. The voltage is sourced by pin 1 of IC8 (TL064 Op Amp) and that has a -8V to +12V supply. That output is clamped to a maximum of 5V By D30 and divided *down* by R87 & R88 before it hits the input (pin 6) of the A/D converter. If you are measuring 36V on one side of D30 and 5V on the other side there is something catastrophically wrong with your meter or your methodology.

Try using Pins 9, 10 or 11 on the ADC0838 as your ground reference and measure pin 6 again.

Before you dive back in with a meter, beg, borrow, steal or make a serial console cable and ask the UPS itself what it is seeing.

[Anonymous user]

Thanks Brad.

The serial cable I have is not communicating between the ups and my system ill be pleased if you can help me with diagram on how to convert one end of my serial cable to usb.

More so, I discovered that the problem is actually with IC17 which has link with the transformer. I changed it and the sharp noise stopped and everything became OK. It worked well (with the transformers of the SU3000)on battery without the overload signal. But when i connected it to work online, it flashed the mosphets and started behaving like that SU3000 that I sent you a video on how it was behaving.

Its obvious that the transformer of the SU3000 is what's disturbing the boards. But I've resolved at working on the board and use another transformer with it. Meanwhile, I still need a diagram on how to connect serial cable with my laptop using usb on the other end as my laptop is not having the serial port.

[Anonymous user]

Its a normal APC UPS with serial number; GS0036000278 and model SU2200XL

[Brad_C]

Serial cable :

http://networkupstools.org/protocols/apcsmart.html

USB to Serial converter :

http://www.ebay.com.au/itm/Com-Port-Serial-Convert-Adapter-Ch340g-Usb-2-0-To-9-Pin-Rs232-Ic-New-L-/2...

[Anonymous user]

Thanks Brad, I've place an order for it though not with eBay but with a local online store (Konga) as I don't have a dollar account to make purchase from eBay. 

I'll give you feedback as soon as I get the cable though I'll still try the initial one you sent.

Thanks a lot, you've been of help immensely. I sincerely appreciate. With people like you and aa forum of such, I can boast of using and fixing APC UPS.

You guys are wow!

[Brad_C]

Pretty much *any* USB to serial converter/cable will do the job as long as you put the APC "smart" cable on the end of it. You don't need to wire up any of the control lines, GND, Tx & Rx are all you need to talk to the UPS.

[Anonymous user]

That smart cable is where the problem lies, as getting it is always difficult.

I have one normal printer USB that I've tried severally but its not communicating with my ups. Could it be compatibility issue? I was actually thinking with the serial to usb converter, any usb cable will work it.

[Brad_C]

On 4/9/2017 11:31 PM, Samuel said:

That smart cable is where the problem lies, as getting it is always difficult.

Which is why I pointed you at a diagram that shows how to make one. Have you done that?

On 4/9/2017 11:31 PM, Samuel said:

I have one normal printer USB that I've tried severally but its not communicating with my ups.

I don't know what a "normal printer USB" is. I certainly haven't seen a printer with an RS232 port for a few years now.

On 4/9/2017 11:31 PM, Samuel said:

I was actually thinking with the serial to usb converter, any usb cable will work it.

Have you got a USB to Serial converter, and have you put an APC Smart cable between that and the UPS?

[Anonymous user · Accepted solution]

Yes I've gotten a usb to serial converter and I've also gotten a powerchute cable using the diagram you sent, but its still not seeing the ups using pcbe agent

The cable i got, when I plug it to the ups when powered on it switches from source to battery and the battery graph indicates 2 bars. I don't know if that's how it works.