Inverter Generator

[acdc]

I bought a ups (Emerson AP203) from a junk yard its 2.5KV Online UPS it’s a nice peace of work. UPS works fine except the batteries are dead 12V 6ah 30 pcs Batteries in series connection that supply a DC of more than 370V its labeled caution 410V DC.

I gave it a test run by plugging it  and for batteries I convert 220AC to DC with a full wave rectifier and 2200uf 4000V DC capacitor UPS started but it shows battery low coz its not getting its full supply . Replacing batteries pretty expensive what is my plan is  for the DC 410V get a 950W Generator and rewind it to  get an out put of 410DC and supply it to the UPS so when black outs I can use the UPS as a power source like and Inverter Generator will it work? What are the modifications I need?

Please let me know your ideas 

ACDC

[acdc]

Hello,

Is there any one could help me out please


ACDC

[ante]

Hi,

I believe there are too many unknowns in your equation to give a short or precise answer. What you have told us so far brings up a few questions like: What’s the UPS requirement for the input voltage, stability, current, noise and so on? The generator, data, how to run it, how to regulate its output so that nothing’s going to fry?
And this is just to begin with! 8)

[acdc]

here u go

220Vinput  220V out put  13.5V sealed lead acid bataries 30 pcs in series conection that produce around 410VDC

bataries are dead now im trying to run it witout bataries with the help of a generator
during black outs

ACDC

[ante]

Hi acdc,

Sorry, not much to go on. The output from the generator might have noise which won’t be accepted by the input electronics. The surge at startup might stir up some EMF which could be lethal the electronics! As I said “too many unknowns in your equation to give a short or precise answer”!

[MP]

acdc,
Is there a chance that this unit has a schematic attached inside that you could scan and post? It would be much more helpful to see how it is already setup.
As ante has mentioned, there are too many parameters to be able to give a "one size fits all" type of answer.

MP

[Gazza]

acdc,
Is there a chance that this unit has a schematic attached inside that you could scan and post? It would be much more helpful to see how it is already setup.
As ante has mentioned, there are too many parameters to be able to give a "one size fits all" type of answer.

MP

I know this is an older post, but I have a lot of UPS experience.

It sounds like you found an old Emerson UPS with bad batteries. Most likely there is only a few bad batteries in the string so you wont need to replace all of the batteries.

What you need to do is get a constant current supply and inject each battery block with 10A of current. With a DMM measure the voltage across each cell. You should get a voltage in the 80-150 mv range. If the drop is above 1V there is an open cell and you need to replace that block.

Since all of the batteries are in series they all need to be functional for the string to operate.



As far as the generator is concerned, are you trying to use a DC generator to power the DC bridge? Or using a transfer switch have a standby AC generator.

I guess it doesn't matter because neither will work.


DC Generator: If you use a DC generator to feed the DC Link during a power failure, what is going to turn the generator? The Power is off, that's why you bought a UPS.  I can think of at least 3 more major problems this would cause.

AC Generator: This wont work without batteries either. The function of the batteries is to bridge the gap between the beginning of the power failure and the time it takes the generator to ramp up to full voltage.

If you want your UPS to work, you are going to have to invest in the new batteries.