20 Most Recent Powerware 9120 UPS System - Page 5 Questions & Answers

Here is the 9120 documentation page but Eaton generally does not publish circuit diagrams for smaller UPSs like this. Some people may be technical enough to take a UPS apart but most aren't and it can be very dangerous. I suggest you contact the Eaton hardware support forum.

I would contact Eaton's hardware support forum in Europe. Here is the documentation link for the 9120 UPS:

Hello, it is possible that the battery inside the UPS needs to be replaced as it may no longer be able to hold a charge. If you can test the battery for voltage, and it is less than what it should be, replace the battery. If the battery is what it should be, then your UPS has malfunctioned, and there is not much you can do to fix it.

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Unless new and hardly used - check the internal batteries. They might be worn out and fail to hold a proper charge. This to be able to deliver power when AC mains cuts out.

Not sure what you mean by load the batteries. Replace them? Yes. Bypass mode is typically used when servicing the unit. You can email Eaton if you like: [email protected]
Here is the legacy documentation page for the 9120 UPS:

saca el disyuntor diferencial y en su lugar pon un disyuntor magneto termico y ya ....
me pasa comunmente ne laboratorios quimicos cuando dejo los diferenciales con respaldo ups saltan a la semana de uso por estatica...

according to the manual the output of the unit is short circuit and it should be turned off and the service agent contacted
http://www.google.co.uk/#sclient=psy&hl=en&q=Powerware+9120+UPS+o%2Fp+short&aq=f&aqi=&aql=&oq=&pbx=1&fp=2b902bc76319272e
first link on page should be a pdf manual for this unit

1st, the 9120 is a 700, 1000, 1500, 2000, 3000, 5000 or 6000 Va
if it is a 6000 Va that voltage sounds ok, and the ups as no problem, each battery will be around 12,75 Volts, it will be higher and the charging circle ends.

chek the optocoupler 3sd12

There is a line detection circuit which is coupled to the logic gate to switch on the charging as it should activate the circuit.
So check from the circuit on the ac line detection and the signal feed to the circuit, there can be a failure on this circuit. Secondly there is a possibility that the relay for charging has failed.

The fan replacement is not hard, but it is fiddly.
You need to pull out the battery case to remove DC power. To do this - front display cover off by pushing up the plastic tabs inside the bottom front of the cover and tapping the top of the cover to release the top tabs. Undo the screws on the metal plate which hold the battery in place. Take off the UPS outer metal case cover using a Torx screwdriver. Undo the 4 screws on the back holding the steel fan cover. Using needlenose pliers or a very small screwdriver, carefully remove the fan connector from the back PCB board. This connector is fragile and tends to break easily. Pull out the fan. Note the location of the 2 screws on the inside fan cover. I use a NMB-MAT Model 3610KL-04W-B50 12 volt DC replacement fan that I order in specially from any wholesale electronics shop as you want the maximum CFM out of the fan. You need to cut the existing fan leads and solder the existing connector leads to the new fan lead, using heat shrink tubing. The connector goes back in only one way- note the dimple on the side. The leads can be a little longer on your completed fan assembly. The fan manufacturer's label should face the back of the UPS.

This solution is for a PW9120-1500. I assume your UPS is PW9120-3000 or larger. Check the model of the existing fans.

If it a 9120-700VA then the problem should be Diode MUR460

If UPS is displaying "Site Fault", it is doing its job correctly. You need to check the wall receptacle. Probably hot and neutral reversed, or the neutral and ground are reversed, by whom ever installed the wall receptacle. You need to have the plug-in for the UPS intact, i.e. the ground pin must not have been cut off. If an extension cord connects the UPS to the wall, thge cord must be working correctly.

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

Suspect battery failure/faulty cell in a batt
Remove batts and check outside unit
charge up to around 2.27V/cell then check discharge on each batt (12V car lamp is good dummy load)
faulty one will be obvious.

MAKE SURE YOU ARE VERY CAREFUL WITH BATTERIES, THEY ARE VERY DANGEROUS, AND ALWAYS LIVE!

Check you manual for safety procedures, BEFORE working on Batteries.


hope this helps

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