Smart UPS SU 700 INET does not work correctly

[Anonymous user]

UPS APC SU 700 INET

Hello,

I have three of this units here, but only ones is working correctly. The others are going haywire.

One needs yet without load a current of 10 A, what is very fast deadly for the Batteries.

The other does not switch off one of the relays, if I switch off the unit and pull out the plug. All the time is still flowing a current of 300 mA. Therefore the Batteries are discharged after a while.

But without a wiring diagram I can not find out any reason. I´m appreciate for any helpful tips.

Many regards

Torsten

Hallo,

ich habe drei von den Geräten hier, von denen aber nur noch eines richtig arbeitet. Die anderen "spielen verrückt", um es vorsichtig auszudrücken. Eins hat bei Batteriebetrieb schon ohne Last eine Stromaufnahme von 10 A, was die Akkus natürlich nicht lange mitmachen und das andere schaltet eins der Relais nicht ab, wenn man es ausschaltet und den Netzstecker zieht, so daß ständig ein Strom von knapp 300 mA fließt. Damit sind die Akkus nach ein paar Stunden dann auch leer...

Aber ohne eine Schaltung ist da nicht viel zu finden. Ich bin dankbar für alle hilfreichen Tipps.

Viele Grüße

Torsten

[BillP]

I understand dear

What I am doing is beyond the average user's realm and its understandable that customer service agents may not be equipped to go such depths.  Wouldn't it be reasonable then to refer me to someone who can?

Considering that there are no authorised repair agent here (S.E. Asia), who knows maybe I will become one to support your products in future.

Yes, tell me more about the serial comms approach.

[BillP]

well you can certainly use this forum and anyone who wants to help can but since this unit is not user serviceable, none of the employees whether it be me or engineering will discuss with you repairing of this unit.

as far as serial communications go, do you have a 940-0024 or 940-1524 DB-9 to DB-9 serial cable available? we need to start with that and we can use PowerChute Business Edition Agent to try and communicate with this UPS (which can be downloaded for free). alternatively, the third party alternative apcupsd (from apcupsd.org) will work too.

[BillP]

if there is any willing to help, tomue88 would not have left the forum disappointed 2-3 months ago.

I successfully installed a usb-serial converter driver on my laptop.

With UPS on, without utility & load connected, all LED lit,

I connect the converter.  After few seconds, the UPS auto shutoff... strange!

Any idea what is wrong? if not I will go look for an older pc and the serial cable tomorrow.

By the way, do I need one that has pins 2 & 3 crossed or straight? a drawing would help here.

Powerchute business ed, latest version? or an older one? a link would help too.

[BillP]

You need the 940-0024 or 940-1524 which even though it is a proprietary cable, you can probably find some information about the drawing out on the internet some place. Since this cable does have a special pinout, connecting a non APC cable or the USB to serial adapter directly between computer and UPS could definitely cause that.

PowerChute Business Edition Agent is all you need (as the installer comes with Agent, Console, Server) so you can just install that component. Software / Firmware is the link where to download that. Just select Software Upgrades - PowerChute Business Edition from the list and press submit.

[BillP]

HI

I am trying to repair a APC Smart UPS SU700 INET myself.

I found some schematics. Some errors below:

1. IC8 TL064 4th comparator is used twice. One of it should be using pin 8,9 &10 instead of 12,13&14.

2. One of the R77 should be R71.

My failure symptom is All LED on front panel lights up.

I have checked the following:

1. With AC input disconnected & batteries disconnected, batteries each are 12.9V

2. With AC STILL disconnected & plug in batteries, there is a small spark.. I think this is quite normal.

3. Press Test & All LED lights up, but no continuous audible buzzer. I read somewhere when ALL LED lights up there is an internal fault & will be accompanied by buzzer.  Is no sound normal when there is a fault ?

4. I then check the power rails. 12V, 5V & -8V all present.

5.No obvious burns or smells

Any help appreciated Angela N?

Hi, Tomue58

Hope the schematics is useful.  by the way, I hate to throw out things, I guess we belong to a gen of DIY engineers.

Maybe we can share more about our findings?

Only worry I have is whether the APC custom ICs are still available?

cheers

[BillP]

These UPSs are not user serviceable so I or any other APC employee can't really help you here. We'd have to advise it go to a certified APC repair partner such as CoastTec (CoastTec, powered by CBM | APC UPS repair service and maintenance | APC refurbished UPS). Anything you do will be at your own risk as we do not distribute schematics ourselves or encourage repair. If you're experienced, then fine and you can share information here knowing it is at your own risk and to be careful.

[BillP]

dear Angela

thanks to state the obvious dear.

I am trying to fix it for a friend, who had stored it away for > 10years.

It was working ok then.

Press "test" and no joy

Open up & checked batteries.. they were both 0.something volts.

Tried recharge batts for few hours.. could not retain charge.

Replaced 12V 7AH equivalent and without plugging in Utility or Load..

Press "test", but ALL LED were consistently lit, no buzzer.

Press "off" was able to shutdowm.

With utility applied with no load connected..

the ups can auto start, without having to press "test", ALL LED lit... no buzzer.

There is no charging and no ac out.

The above tells me alot.. i.e.

1. the control path from front panel switches to the microP through the ADC/MUX is ok.

2. Being able to auto start when AC input is applied means, the input sensing (AC ok & in-rect) are ok.  This was confirmed by measuring voltages at halfwave rectifier diodes & LM393 comparators output, with/without AC applied.

3. Checked continuity on fuses... ALL ok.

4. checked all supply rails, 24, 12, 5 & -8 vdc.. all ok.

5. Relay RY5 & 4 did not click, hence the 230Vac did not get through to output transformer through relays 3, 6 & 1.

6. Temporary shunting each relay driver transistors to ground produces the clicks I wanted.. so all relays were ok.

it seems like the microP is not issuing the appropriate signal to turm on the relays, start the inverter and activate the buzzer.

Is it because the EEPROM remembers something 10 years back and the microP will not allow it to start ?

How can I get it to factory defaults? or reconfigure.

One thing puzzles me is that

with utility AC applied, it auto-started, but as long as incoming AC (on line mode) is applied, press "off" at front panel will not shut it down.

However, when utility AC removed (inverter mode) & while ALL LED remained lit, pressing "off" was able to shut it down.

Hope you can help dear

Message was edited by: free

[Anonymous user]

UPS APC SU 700 INET

Hello,

I have three of this units here, but only ones is working correctly. The others are going haywire.

One needs yet without load a current of 10 A, what is very fast deadly for the Batteries.

The other does not switch off one of the relays, if I switch off the unit and pull out the plug. All the time is still flowing a current of 300 mA. Therefore the Batteries are discharged after a while.

But without a wiring diagram I can not find out any reason. I´m appreciate for any helpful tips.

Many regards

Torsten

Hallo,

ich habe drei von den Geräten hier, von denen aber nur noch eines richtig arbeitet. Die anderen "spielen verrückt", um es vorsichtig auszudrücken. Eins hat bei Batteriebetrieb schon ohne Last eine Stromaufnahme von 10 A, was die Akkus natürlich nicht lange mitmachen und das andere schaltet eins der Relais nicht ab, wenn man es ausschaltet und den Netzstecker zieht, so daß ständig ein Strom von knapp 300 mA fließt. Damit sind die Akkus nach ein paar Stunden dann auch leer...

Aber ohne eine Schaltung ist da nicht viel zu finden. Ich bin dankbar für alle hilfreichen Tipps.

Viele Grüße

Torsten

[BillP]

Hello. I tried to translate your German as well to see if it'd help understand the issues you are seeing.

If I understand correctly, one of your units is operating on battery power even though it is plugged into the wall (thus, it is not detecting AC power) and the second one seems to be discharging the battery into the chassis when you turn it off, like it is still turned on.

1. On the first one, I've seen this once in a while. Do you have any software connected to read what input voltage the UPS is seeing? What lead up to this problem? I assume you've tried different wall outlets?

1. How long on your second unit until the battery discharges? You're thinking the output relay is broken?

I don't doubt that they are failing (considering it is probably 10+ years old) but unless you have a certified repair center near by if nobody is able to help here, I'd consider trading them in if possible in your location - meaning, I am not sure if your country participates in this program: Recycling Options - recycle Meaning if these are not repairable, at least you could trade them in for some credit on a replacement.

Either way, unfortunately, APC does not distribute schematics but if anyone else wants to provide any input, please do.

[Anonymous user]

Hi again.

Thank you Angela N. for your help.

This one, which has this high current, I can not use. It works normaly if it is connected with 230V and the batteries are charged. PowerChute tells me that all the values are o.k. But if turn out the 230V, there is flowing a battery-current of nearly 10 A and this without a load at the output. And then - if returns the voltage and the unit begins to charge the batteries again, the current is also very high when starting. Later it falls down to normaly values. (I can compare this with the unit, which works correcty.) I think that the PowerMosfets or the drivers do not work correctly, but this is what I mean - it is hard to find something without a schematic.

The other unit works nearly normal. PowerChute also tells me that all the values are o.k.If they turn off the 230V, it works fine with batteries, the battery-current is between 2 - 5 A, depending from load at output. But if the unit turns off, always is flowing a little current of 290mA, also if they disconnect the power-plug. (At this moment, if I disconnect the power-plug, the relay switches of at the unit, that works correct.) Only if I disturb the battery-cable this current stops. You can hear at this moment that a relay is switching off. After break this connection shortly I can connect it again. The relay does not switch on again before connecting the power-plug again. It means, that the relay is working. Here I also think, that the reason is the relay-driver or previously this, but also I can not find anything without a schematic.

Well, I know the units are not new, but I don´t like it to scrap units if I can repair it. I´m a german engineer of electronics and I live in Paraguay. Here it is not so easy either cheap to buy every two years all the equipement new. Repair-centers they do not know here nearly the jungle and I´m sure that Paraguay do not participate in any recycling program.

The only way, I believe, is to get the schematic for the units or to get help from anyone, who knows this units.

However - thank you for helping me. May be there is anyone who can help me to solve the problem.

Saludos

Torsten

[Anonymous user · Accepted solution]

Does not anyone work with this machines?