Question about UPS Battery Backup Systems

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UPS problem When my UPS is on without load, it shows the " main power on " which is normal. but once i connect it to a load and switch on, it transfers from main supply to battery supply even if the main power is on. Can you suggest me how to go about this problem?

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It sounds like you have a problem with your load, are you getting any alarms and what kind of UPS do you have do you have and what is your load , moters .pumps, computer get a service manual. on your UPS if you can or contact tech support

Posted on Oct 04, 2009

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Hi,

Based on your post/description, two (2) possibilities:
1. electronic fault - main power/AC mains sensor which could be really just a relay; or
2. corroded fuse terminals or fuse holder.

The first is a bit of a challenge since different brands/models have different sensing circuitry design. Some can be as earlier stated, a simple AC relay while others could be a TRIAC switch with a DIAC trigger. Still, some could be an elaborate AD converter and a myriad of logic circuitry. Often, a service manual or at least a schematic diagram would be needed, however these are not that readily available and most often the tech or DIYer must resort to winging it. This of course would require familiarity with electronic circuitry and components, use of a DVM and a soldering iron. Extreme caution must be exercised since even with 12VDC supply most of the electronics are at least at 60VAC+ level.

The 2nd possibility would be of course be the easiest to determine and repair. Replace/clean.

Should the downtime & repair cost makes the project no longer economically reasonable, perhaps your best bet would be to simply replace the UPS since their prices are relatively low.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

Thank you for using FixYa.

Posted on Apr 16, 2008

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2 Answers

GE LP33 UPS inverter failed to start


Dear Yared,

Did you try to give the UPS some time to recharge the batteries?
Seems like the batteries have reached their cut-off voltage and are not supplying enough voltage to the inverter.

Normally the dc boos circuit of the UPS will supply voltage to the DC BUS so maybe the problem can be found in the dc boost circuit or BUS if recharging the batteries is not helping.

Let me know.

Best Regards,


Ron

Jan 22, 2013 | MGE UPS Battery Backup Systems

Tip

UPS - Battery Fault


UNINTERRUPTABLE POWER SUPPLY
Batteries in the UPS typically last 3 to 5 years and it depends upon several factors. Including the number of times the unit must go on battery power and environmental conditions. There are usually several batteries in the UPS and while the battery voltage may show 13 volts, this may only be a float charge/voltage and a true indication of the battery voltage and condition requires the batteries to be tested under a load. If one battery is faulty in a set of batteries it will causes the whole battery system to fail and indicate a battery fault. A faulty charging circuit will not charge the batteries and will also cause a fault condition.

Lower powered and cheaper type UPS are switch over types, when the mains supply fails, the UPS switches over to the battery and inverter in milli-seconds which then supplies mains power to the computer and peripherals. A faulty inverter circuit and or flat batteries won’t deliver standby power when the mains supply fails.

NOTE the power waveform from these UPS is a pseudo sine wave (i.e. not a true sine wave).

The true UPS types are usually the higher KVA units (over 1500 VA) that supply continuous mains power. The mains power is connected to a charger which charges the batteries and the inverter draws power from these batteries and converts it to true sine wave mains power to the computer equipment, therefore there is no switch over time lag when the mains supply fails.

on Dec 02, 2009 | UPS Battery Backup Systems

1 Answer

SUA3000RMI2U won't carry load


Did you run this test without AC input?
Also what happens when you cut off the AC mains without any load connected to it? Will the UPS continue to run or does it switch off as well?

Dec 15, 2012 | APC Smart-UPS 3000VA USB & Serial...

3 Answers

Can i have all the basic details of UPS system


UPS come in two types, lower powered cheaper types are usually switch over power.
These units senses a power outage and then switch over to the battery power to generate mains supply. The switch over occurs in milli-secs and does not affect the computer.
True UPS types constantly run off battery power to generate mains supply so there is no switch over time lag. These units are higher powered and higher costs units.

Both type of UPS have the same components.
Battery charger.
Batteries
Inverter that converts battery voltage to mains voltage
Electronic controls

Dec 16, 2010 | Emerson PowerSure Personal 500VA...

3 Answers

Our apc ups showing overlaod when power is switched on


I am assuming that nothing is plugged in when powering up. This usually means that there is a short or damage to the unit. This forum discusses the issue: http://www.apc-forums.com/thread.jspa?messageID=15110

Dec 31, 2009 | APC Back-UPS RS 800VA UPS System

2 Answers

Dc bus faulty


Batteries in the UPS typically last 3 to 5 years and it depends upon several factors. including the number of times the unit must go on battery power and environmental conditions. There are usually several batteries in the UPS and while the battery voltage may show 13 volts, this may only be a float charge/voltage and a true indication of the battery voltage and condition requires the batteries to be tested under a load. There maybe one battery in a set of batteries that is faulty and causes the whole battery system to fail and indicate a battery fault.

These lower powered and cheaper KVA type UPS are switch over types, when the mains supply fail, the UPS switches over to the inverter in milli-seconds which then supplies mains power but the power waveform is a pseudo sine wave (ie not a true sinewave. A faulty inverter circuit won’t deliver power when the mains supply fails.

The true UPS types are usually the higher KVA units (over 1500 VA) that supplies uninterrupted mains power. The mains power is connected to a charger which charges the batteries and the inverter draws power from these batteries and converts it to true sine wave mains power therefore there is no switch over time lag from the mains to the battery.

Oct 22, 2009 | Powerware 9120 UPS System

1 Answer

Sir after changing the battery ups worked well one day and the next day onwards when i pressed the switch red and amber lights blinking and the upc trips with beep sound .kindly give the solution


Batteries in the UPS typically last 3 to 5 years and it depends upon several factors. including the number of times the unit must go on battery power and environmental conditions. There are usually several batteries in the UPS and while the battery voltage may show 13 volts, this may only be a float charge/voltage and a true indication of the battery voltage and condition requires the batteries to be tested under a load. There maybe one battery in a set of batteries that is faulty and causes the whole battery system to fail and indicate a battery fault.

These lower powered and cheaper KVA type UPS are switch over types, when the mains supply fail, the UPS switches over to the inverter in milli-seconds which then supplies mains power but the power waveform is a pseudo sine wave (ie not a true sinewave. A faulty inverter circuit won’t deliver power when the mains supply fails.

The true UPS types are usually the higher KVA units (over 1500 VA) that supplies uninterrupted mains power. The mains power is connected to a charger which charges the batteries and the inverter draws power from these batteries and converts it to true sine wave mains power therefore there is no switch over time lag from the mains to the battery.

Oct 16, 2009 | APC UPS Battery Backup Systems

1 Answer

Dead appearing ups/inverter


keep on your main switch. off all the lights fan and other electrical items, let that inverter get charge first

Jun 18, 2009 | APC Back-UPS CS 500VA UPS System

2 Answers

LCD shows Low O/P V


Fault: Low Ouput Voltage

Cause: Surge Taken by load / Short Circuit on load / Fault in inverter

Remedy: Remove load and restart UPS / Try a different load / Repair or swap out

If you need spares or price for repair contact Eaton Power Quality Ltd - the new name for Powerware - 01753 608700

Dec 15, 2008 | Powerware 9120 UPS System

1 Answer

Dynex TE685AVR - wiring problem light on


yes first disconnect the pin of load then switch off ups then switch on check ac voltage at output if comes and disappears when load is connected then battery is faulty it shows voltage without load but disappers when load is connected replace battery

Nov 09, 2008 | Dynex (TE685AVR) UPS System

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