Question about Sola SDU500 UPS System

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SDU500 UPS When ac power comes back on line the battery back-up does not transfer back to normal

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Re: SDU500 UPS

I've had the same problem.It ended up being that the incoming AC voltage was above (or below) the specification of the SOLA SDU500.I never thought I'd see something like this.The city that I was putting these in for, at sewage lift stations, runs their own power crews and they replace a transformer up on a nearby power pole!All is good now.

Posted on Jan 15, 2009

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Re: SDU500 UPS

I have the same problem. The unit was working perfectly until we had a power outage. Once the power was restored, the unit (battery side power outlets) stopped working. It won't power on upon pressing the power switch (I've tried plugging and unplugging.) The little red (fuse or circuit breaker) thingie at the back is loose. Any ideas?

Posted on Jan 31, 2008

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Apc xs900 will work off batteries not off ac

So something happened to this apc and the first thing is to replace batteries...
I'm going to guess major circuit board failure.
go to apc site, download Power Chute software and pray there are useful diagnostics.

Mar 31, 2014 | APC Back-UPS XS900 (BX900) UPS System

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Hello ! I have a problem with my apc smart ups SUA 1500VA. It changed to battery use from AC line altough the AC line was working just fine. I don't know what happend. I found it like that when i came...

Battery not connected properly. Check that the battery connector (rear panel) is fully engaged.
Press the on/test button once to power the UPS and the connected equipment.
Make sure UPS has nothing connected to it. Check the Fuses for the battery inside in the back of the UPS
Unplug UPS and batteries. Push the on button to clear the logic. It may or may not flash the LED's Once the fuses are checked, check the logic boards for any burn or discoloration.

Sep 25, 2011 | APC Smart-UPS 1000VA UPS System

1 Answer

4 beeping sound every 20 seconds, even when there is no gadget attached to it.

This alarm indicates that the UPS has transferred from On Line operation to On Battery operation. The Battery Power Supplied outlets are now battery powered.

- If the input voltage is determined to be unsafe for your computer equipment, the UPS will transfer to On Battery. The alarm will stop once the unit returns to On Line operation. Please refer to the technical specification section of your user manual for the acceptable voltage window. Occasional transfers to On Battery should not be a matter of concern, but rather, should be considered normal operation. The UPS is trying to provide clean, safe, and reliable power. If your unit shipped with APC management software it may be possible to change the default acceptable voltages that the unit shipped with. Please see the help section of the APC management software for instruction to do this.

- If the Frequency deviates + or - 5 % this will also cause a Back-UPS product to transfer to battery power. Frequency distortions are most commonly caused by generators that are undersized. Always make sure a generator is 3 to 5 times the size of the total load attached to unsure it can maintain a steady output frequency. There is no way to change the +/- 5% deviation.

- If the shape of the incoming power is considered "too dirty", some Back-UPS products may transfer to battery power. This is most likely the problem if you have already confirmed that the input voltage is within the acceptable limits. Most Back-UPS products have the ability to change their sensitivity to the shape of the input power from high to medium or even low. Please see your user manual for details as to how to adjust this setting.

Jun 27, 2011 | APC UPS Battery Backup Systems

1 Answer

I hit the button to turn it on it will stay on for awhile and then it will start beeping really loudly an shut off

With your UPS turned off, unplug your PC and all other devices from the unit. Then turn the UPS on. If it still beeps and shuts off your UPS internal battery may need to be replaced or you have an internal UPS failure. Look for a red "battery alarm" light on the front of your UPS.

If the UPS does not shut down with all devices disconnected from it, Power off your monitor and look on the back of the monitor for a label which will tell you the amount of power it requires (probably 100 watts or less). Plug the monitor's AC power cord into your UPS and turn on your PC and monitor. With the UPS plugged into the AC line you are not using the internal battery and the UPS should remain on and your monitor should be working. If it shuts down you have an internal problem with the UPS.

Now unplug your UPS from the AC line (simulating a power failure) Your UPS is rated at 350 watts. Accordingly it should easily support the 100 watt load of your monitor. If the UPS continues to provide power to the monitor for 1 or 2 minutes down it's an indication that it's working properly and the COMBINED LOAD of your monitor. PC etc. when plugged into the UPS is exceeding the 350 watt capacity of the UPS. You will have to disconnect 1 or more devices from the UPS.

NOTE: Never plug a laser printer into an UPS.

If the UPS immeadiately shuts down after disconnecting it from the AC line with only the monitor plugged into it you have a bad battery.

If you found this information to be helpful to you please return to the FixYa website and rate me.


Dec 07, 2010 | APC Back-UPS ES 350 - UPS ( external ) -...

1 Answer

Powered from a generator the APC 3000 UPS running on AC power and running on battery lights come on alternately

It is possible that the auto power detect section has gone faulty and is switching in this shunting manner because of an error in the line detect section. The op amp is detecting a low voltage to switch on and doing so it goes back to power. This can be due to a frequency problem in the AC generator and so If you switch off the generator the fault must stop.
If so have the generator checked for frequency change or the UPS has a circuit error. Try to set the AC voltage of the generator up to the required level if there is a drop on load.

Sep 28, 2010 | NEC APC Smart-UPS 3000 RM 3U...

1 Answer

Strange noise comes out from the ups after a power cut

The Back-UPS Office unit has five different tones or alarms:

1. Four beeps every 30 seconds (On Battery LED will be illuminated)
This alarm indicates that the Battery Power Supplied outlets are now supplying battery power as opposed to power from the utility. If the UPS determines that the input utility power is unsafe for your computer equipment, the UPS will switch to battery power.
Note: If the power disturbance is brief, you may only hear one or two beeps.

2. Continuous Beeping (On Battery LED will be illuminated)
This alarm indicates that a Low Battery condition has been reached and that the UPS will soon shutdown. Once the UPS transfers to On Battery operation, it can only stay on battery for a limited amount of time. The UPS will sound this alarm about two minutes before the batteries are totally exhausted. Once exhausted, the UPS will shutdown and turn off its output power to your equipment. If you hear this tone you should immediately shutdown your computer to prevent data loss or corruption.

3. Continuous Beeps for 30 seconds (Back UPS OFFICE 250 and 280 ONLY)
This alarm indicates the unit has detected an Overload condition after it has performed a self-test during start-up.

4. Continuous Two-Tone Beep
This alarm indicates a severe Overload was detected while the unit was on-battery operation. This tone will continue to sound until the unit shuts down.

5. Continuous Tone (On Battery LED will be flashing)
This alarm indicates that the battery-powered outlets are overloaded.

6. Continuous Tone (On Line and On Battery LEDs flashing) Back UPS OFFICE 350, 400, and 500 ONLY
This alarm indicates that an internal UPS fault has occurred.

Jan 06, 2010 | APC Back-UPS ES 700 - UPS ( external ) -...

1 Answer

After a power outage my apc has this clicking sound. every 4 seconds or so it sounds like it clicks and then a slightly different click 4 seconds later. However, when everything is powered up it doesn't...

I found this on the APC website;
Question: What would cause a Back-UPS Pro, a Back-UPS Pro USB, a Back-UPS RS, a Back-UPS CS, a Back-UPS LS, or A Back-UPS XS to beep once every 5 seconds with no output power?
Answer: One beep every 5 seconds is an indication that the UPS has entered what is called "Low Voltage Sleepmode".
The Back-UPS product has transferred to battery power due to a low voltage condition at the wall. The Back-UPS has remained Onbattery until its runtime was totally exhausted, however, there was still enough voltage present at the wall to trickle charge the battery.

This is considered to be a normal operating state. When the voltage returns to normal the Back-UPS will wake up and restore power to the battery outlets.

Nov 02, 2009 | APC Back-UPS ES 350 - UPS ( external ) -...

1 Answer

Powerware ups mod #PW9120100i

You have to turn socket of ups power cord 180 degrees, because the ups is measuring voltage between ground and ac-line.

Aug 25, 2008 | Powerware Series 9 9120 UPS System

1 Answer

Ups troubles

What is happening here is you are transferring load to battery during a power outage but on return of Line Power the UPS is not smoothly transferring back to Normal mode. As a result you are basically turning off your computer. Two options... shut down your computer orderly during an outage or buy a new UPS.

Dynamic Power Solutions LLC

Aug 20, 2008 | UPS Battery Backup Systems

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