UPS synchronization question

[phil b]

I bought a palet of old UPS's at an auction. Most of them were marked as "bad". Actually, the batteries were the only thing bad. The units work perfectly.

I want to use several identical APC 1400 units hooked in parallel to get 120 vac and 30 amps. Reason: I get 90 vac from the genny's long transmission line and need to use the units to bump the voltage back to 120 vac. Unfortunately, the no single UPS is capable of producing 30 amps.  

So, if the unit's inputs are in parallel, will the 120 vac coming out also be synchronized as well? If it is, then the output can also be paralleled for more amps?

[ibedonc]

not easy to do , (do you have the schematic ?)  without electronic surgery

and then I still do not think you could do it

[phil b]

Hi ibedonc,

Sorry, no schematics. IMHO, I'm thinking the electronic switching on the units would have to be very precise or somehow syncronized electronically like Xantrex. I wanted to ask the board before letting out the magic blue smoke!

Thanks

Phil

[commanda]

The obvious solution to your problem is to run some heavier cable and/or move the genny closer to your load.

Amanda

[scottsAI]

The answer can go in several directions.

The 90VAC is this 60hz?

    Yes, then you want the UPS to boost the voltage using the AVR built in?

         You might be in luck.

    No, I don't understand.

        What generates the 90vac.

         How far is far?

         Need more details!

The APC 1400 draws 30 watts on AC. You probably don't want this.

The APC 1400 does not do parallel. But depending on what your trying to do... maybe something can be worked out.

Have fun.

[dalibor]

hello phill.

it is very hard to connect two or more sources of AC current into parallel, becouse they have to match by phase and by voltage. the first one  ( by phase) is much more complicated. you can connect their inputs on the same DC ( or AC ) source, but AC in output is hard to sync. to other AC. producer. its requires very compl. electronic regulation

[phil b]

I have 1 wind generator and solar panels that's located next to my 'greenhouse/battery shed'. Currently, I'm using 2 Xantrex C40 charge controllers in diversion mode. This heats the greenhouse in winter. I'm also using a UPS to convert to 120 vac, 60Hz and send it 1750 feet down the line through a 2/0 alum cable to where the majority of my electric loads are located. The UPS on the end boosts the AVR from 90 vac to 120 vac. I need more power on the end.

The short answer would to buy larger UPS's or Xantrex. The long and much cheaper answer might be to use multiple UPS's and combine the amperages to produce more power on the end of the line. The UPS's were very cheap. I can't buy the transformers for what I paid for the entire units. I'm also handy with a soldering iron and have a lot of experience safely handling high voltage. So if UPS modification is an option, the blue smoke won't be from me!

Amanda, from your posts, I see you are using a toroid to boost voltage to minimize transmission line loss. If you had multiple wind generators, how would you combine the power to send it to the load?

Thanks for the responses. Any more ideas are also appreciated!

Phil

[nothing to lose]

A quick question, why do you need 30amps? Is this for all one load like a heavy motor or is it going to be all split up again going to different devices?

If split up to diffferent devices can't you just set up line 1 15 amps, line 2 15amps and power 2 sections of the house seperately that way from the 2 Ups's?

Besides being easier probably, if 1 UPS dies only the 1/2 house goes dead. The other way if 1 Ups dies it tries to throw the enitre 30 amp load to the second Ups and either over load shutdown or frie it too, so you would lose the whole house at once.

If you need 30 amps for one device then you need it.

"I bought a palet of old UPS's at an auction. Most of them were marked as "bad". Actually, the batteries were the only thing bad. The units work perfectly."

"APC 1400 units hooked in parallel to get 120 vac and 30 amps."

These are supposed to be rated for 15amp 120Vac output?? That's 1800watts

Do you have extras you want to sell cheap, if so without batteries what would you think shipping would cost. I may be interested in a couple myself if not too expensive to get them here. Long as they work I can add my own batteries just fine

I have not tested the thought, but I wonder if a gennie were built for 120Vac and connected to the AC line on a Ups if the Ups will work when the genie is suppling enough power and conditon the line when power is low or high and switch to battery backup if the wind dies and no power is being made. At the same time when plenty of power is being made the Ups charges the battery bank also as normal like when connected to the grid.

Don't know how that would work, but if you have extras and want an idea to play with

[phil b]

"A quick question, why do you need 30amps? Is this for all one load like a heavy motor or is it going to be all split up again going to different devices?"

30 amps will power all my 120 vac stuff. I can split up the power and use different ups's on individual circuits, but I have no place close to put the batteries. The barn is suitable and 100 feet away. If the ups's would parallel, then problem solved.

"I have not tested the thought, but I wonder if a gennie were built for 120Vac and connected to the AC line on a Ups if the Ups will work when the genie is suppling enough power and conditon the line when power is low or high and switch to battery backup if the wind dies and no power is being made."

I think the stator would get very hot if it were wound for 120 volts. I went with tried and true 24 volt, 3 phase setup on this board. I'm thinking about adding 3 small transformers or maybe ups to the 3 phase output, sending the power to the battery shack and then to the initial ups's for the trip to the barn. It may work if the ups will turn on at cutin rpm. That would save a LOT of line loss in itself.

"These are supposed to be rated for 15amp 120Vac output?? That's 1800watts

Do you have extras you want to sell cheap, if so without batteries what would you think shipping would cost. I may be interested in a couple myself if not too expensive to get them here. Long as they work I can add my own batteries just fine

All of them are rated in watts. The APC Backups Pro 1400 also says 950 watts on the back. I think that's what it will handle on inductive loads. 1400watts/120vac = 11.7 amps. IFFF my math is correct I'd also need a minimum of 3 identical units to get 30 amps. Also, I doubt the units are made for continious use, so I'd probably need double the rated output to be on the safe side.

 I have APC units 1400, 1000, 900, 420 and 400 watts. Tripp units are 1150, 1050, 700, and 450 watts. Most came in multiples of threes. No, I don't need all of them and if your are interested in a few cheap without batteries, send me your email.

Thank for the ideas!

[nothing to lose]

I set up a new e-mail address now just for this forum.

nothingtolose175 at yahoo.com

People often ask if the number means anything, it represents how much money I have at any one time, $1.75

Really it means nothing, but it seems even the most odd names are taken, so adding the 175 to all my acount names works most of the time.

[Nando]

SINCE YOU ARE asking about synchronization it is a clear indication of your knowledge in electronics -- DO NOT Attempt this project.

Regarding your power source that is wasting about 35 volts at 30 amps (1050 watts) -- you have two solutions

1. the Right one, to change the wiring from aluminum to copper with the proper current capability.
   
2. Or get 2 - 7 to 10 KVA transformers ( sometimes you can get them as scrap from the power companies)like 230 center tap to 2400 volts AC.
   
   

Connect 115 Vac to the 115 Volts tap, then send to the remote site 2400 Volts, then in other place, connect transmission line to the 2400 Volts, then the other you will have 115 / 230 volts available, the drop looks like is going to be about 115 / 2400 * 1050 watts = 50 watts or 115 / 2400*35 volts= 1.7 volts AC

You may as well get smaller transformers ( 5 KVA) 115 / 1200 or even 115 / 480 volts, all depending on your power generation and limits and pocket size.

3) Get one transformer 2 KW primary 115 Vac, secondary 40 AC Volts then place the secondary in series with the Vac going to the transmission line, to generate 155 volts at the source -- but if the current drops the voltage goes up.

This will be the last resource. -- you may need a ckt to regulate the voltage.

Regards

Nando

[Hans]

Why not buy a device kwnon as STAVOL.

They are basically torroids with a mechanically driven slider.

[scottsAI]

You have an interesting problem, With many possible solutions.

I must admit, I'm confused about the situation.

Could you draw up your system?

Include, Power generated in watts:) one phase three phase? How it's generated.

-Each power source if more than one.

-wire size, wire length. All wires.

-Each location the power needs to be used and how much. Voltage and current.

-Back up batteries? Where located etc. wire size...

The more details the better we can help you.

I have recently bought four APC 3000 and two APC 1000. I plan to gut two of them and parallel/series to get 220v at 30amps to run my well pump, and other circuits in the house during a power failure. I will be using 8 golf cart batteries. I expect 2 days run time. The UPS's draw 48 watts each doing nothing. I do not like this. So I will be using the transformers and not much else.

Help us help you... details.

Have fun.

[scottsAI]

I opened my APC 3000, it has two 1500 transformers in it. I expect it's much like the 1400.

Primary side has 4 wires: Black, blue, white, yellow. Secondary 2: white, black.

The primary side is all you need. APC uses it as an autotransformer. Measure the voltage on them, (or trace them if you can) Try to match them up to:

__150v

/

_120v

/

_90v

/

\

/

\

/_neutral

When the voltage goes low the AVR connects the output to 150v tap. Boosting the voltage back to 120. If the voltage is high, AVR connects the output to the 90v tap reducing the voltage to 120.

Since your voltage is always low. You can eliminate all of the circuitry. Unplug the connector and wire it up. You can parallel several of these transformers to meet your power demands. Leave the secondary UNCONNECTED. My transformers get warm, Measured 115'F, doing nothing. Not sure if under load they get hotter? May consider a fan.

I take it you have power to burn. The loss of 1kw in the wiring (30%) does not seem to bother you. On eBay a 3kw step-up to 220v transformer is <$100 with ship, By doubling the voltage, the power loss in the cable will be half... don't know if an extra 500 watts is useful. Depending on the step-up transformer, some can do 240v, If your 1750' cable has three wires, the lower losses by using 220v, that may be all you need. You have two 120 volt circuits, or 220 for what ever, with a neutral. Then you can sell off all your UPS.

Have fun.

[(unknown)]

So how many watts does a APC 3000 draw from the source it is connected to when it is charging the batteries in the unit?

Dave