Question about Computers & Internet

2 Answers

Powerware 9120 BUS Unbalanced error display

Got an Powerware 9120 and displays constantly ''BUS Unbalanced'' and when the external power cuts off, there's no electricity anymore... it won't work.
Do I have to replace batteries? some cap toasted?..
Help please?
Thanks a lot

Posted by on

Ad

2 Answers

  • Level 1:

    An expert who has achieved level 1.

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

  • Contributor
  • 39 Answers

The user's Guide for the PW9120 handles 700-3000va - this is the complete range for the PW9120. It does not list a possible alarm of "'BUS Unbalanced''. Unless your unit is a European version, it will be 120 input and output and will have only one inverter internally.
Get the manual or download the full manual from the Powerware site. Go through the UPS settings to ensure they match the factory settings. (By the way, the factory setting for the Input Voltage Frequency should be +/- 5%).

If all the settings are correct, you have may have dead batteries. What does the display show you for battery charge % and battery backup time? If your individual battery voltages are less than 11 volts, your batteries are dead. Test at the battery output connector at the back of the UPS. 9120-700 2 batteries, 9120-1000 3 batteries, 9120-1500 4 batteries - all in series, so the 12 volt battery bus voltage is additive. Use PowerSonic PS-1290 F2, rated at 9.0 Amp. Hr. for the best battery replacement.

Posted on Feb 08, 2011

Ad
  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

  • Contributor
  • 4 Answers

I've had this same issue what it boils down to is that the Power IN is not being distributed properly across the Power Outlets.

Step 1. unplug everything from the unit and power the ups down. If the alarm clears itself the UPS is mostly likely fine. if it doesn't not clear send it in for repair

Step 2. If step 1 cleared the alarm try distributing the decives across the outlets differently.

There are two inverters so two output if everything is plugged into one side (ie a power bar with 10 things plugged into it) and nothing on the other side this could cause the alarm.

hope this helps

Posted on Feb 18, 2010

  • hellwigg Oct 06, 2010

    The 9120 does not have two inverters. There are two sets of input terminals and one set of output terminals. It has one rectifier and one inverter.

    I have had a bus unbalanced alarm a few times and output power is lost. It has nothing to do with two inverters.

×

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

What cause dc bus fault on 9120 power ware ups?


why don't you check the DC bank capacitors, you may need to replace them

Apr 04, 2015 | Powerware 9120 UPS System

2 Answers

Powerware 9120 6000i model indicates a charger failure. It is the first time that we opened this unit and we do not know the location of the charger circuit (we do not have a schematic diag). Could you...


The charger in powerware 9 series 9120 6000i ,the fan is of a quality that it fails and the heat sink does not get sufficient cooling ,it runs on 12 volt ,i replaced it with a cpu fan from a mainboard on a pc and it works perfectly now. make sure that the fan is running else the charger might go in protection or can fail due to the transistor on heat sink fails.

Feb 08, 2011 | Powerware 9120 UPS System

2 Answers

When i power on the ups it show site fault on the display,i checked the earth wire is ok . what can it be a problem?


Hi, here is the documentation page for the 9120 where you can find the manual: http://powerquality.eaton.com/Products-services/legacy/9120-info.asp You can also contact customer support 800 356 5737 or SinglePhaseTS@eaton.com. You may recognize the product as the Powerware 9120 but Powerware was bought by Eaton a few years ago. The customer support team is most ex Powerware and are familiar with the 9120.

Oct 14, 2010 | Powerware 9120 UPS System

2 Answers

My ups has is faulty i need a circuit diagram to fix it


I had a DC bus fault error displayed.

So I unplugged battery, then turned on UPS. It said Batt disconnected of course.

So when I plugged in the batt while the UPS was on, and held the power button for a few sec, the UPS displayed Batt testing.

After a few moments it was back online and had no faults!

Worth a shot.

May 20, 2009 | Powerware 9120 UPS System

2 Answers

The UPS dont go to on batteri


Replace the batteries with new one then power the UPS without load for three hours or more so that the batteries can be charged. Then disconnect or switch off power to the UPS and observe if it will till be on using the batteries. If it will be ON then your problem is solved but if it goes off then your UPS is on BYPASS

Apr 09, 2009 | Powerware 9120 UPS System

1 Answer

UNBALANCED ERROR in display


old school hollywood baseball old school hollywood baseball old school hollywood baseball old school hollywood baseball

Feb 03, 2009 | Powerware 9120 UPS System

1 Answer

Powerware 9120


Greetings!
How many years is your ups working? UPS is usually run by a battery, some of them are disposable and needs replacement. If it does not charge anymore it needs replacement of battery.
Thanks.

Nov 06, 2008 | Computers & Internet

Not finding what you are looking for?
Computers & Internet Logo

Related Topics:

2,300 people viewed this question

Ask a Question

Usually answered in minutes!

Top Computers & Internet Experts

Les Dickinson
Les Dickinson

Level 3 Expert

18424 Answers

Doctor PC
Doctor PC

Level 3 Expert

7733 Answers

David Payne
David Payne

Level 3 Expert

14162 Answers

Are you a Computer and Internet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...