The model is 430-7101(3) and is from an APC UPS and there are 2 of these that run in series - Each has a 4 wire connection on the main board and the terminals on the mainboard look to be in parallel.

I did a continuity test on the 4 wires and wire 1 & 3 and 2 & 4 signal as a single wire. Wire 2 (black) has a 15A 125v inline fuse and all wires are 16awg.

Since this is a UPS, IDK which is considered primary as if it is being battery fed, then the larger gauge would be primary and step up the voltage.? But I didn't think DC could be stepped up like this, Could that be why there are 2 sets of wires on the high voltage side?

I'm trying to find out what the output voltage is of the transformer and wanted to know what wires to use to test 120 AC. I was thinking that using 1 & 2 as + and 3 & 4 as - , but wanted t check if that would be correct (fusing concerned me)

Actually after thinking about it, I think the 2 sets are for 120 and 240. When 120 is detected connector 2 and 3 are "shorted" to make a longer wire. Does that seem possible?

 

If it is a transformer there would be different gauge windings.
Can you see the windings ?
Can you measre the resistance of the windings ?

I once got few of those from a 1.5KVA APC slim type UPS and they turned out to be just inductors....

 

If it is a transformer there would be different gauge windings.
Can you see the windings ?
Can you meashre the resistance of the windings ?

I once got few of those from a 1.5KVA APC slim type UPS and they turned out to be just inductors....

The other side has 10awg windings

I found this video which uses a similar transformer and it was from a similar UPS as this one. He has the 4 connector jumped in some way or it is the live wires connected to the outlet. It looks like he has connected 1 and 4. His transformer is larger than mine it seems.

I tried hooking up 120 to connector 1 and 3 and it tripped a 15A Breaker immediately. 1 and 3 have continuity and 2 and 4 have continuity. So I thought running power through 1&3 or 2&4 would be the right thing. I'm looking for some other vids or posts of people testing units from these UPS's.

 

Yes the two windings are primary and would be connected either in parallel or series depending upon the input voltage. (parallel for 120v, series for 240, for example).

I doubt that those two Transformers are connected in series but it is possible. Typically they be connected parallel to each other each performing a different function in the unit. They are connected to the AC input line ahead of any rectifiers.

If these are older and smaller units one Transformer could be for the input line ahead of the rectifier and the other could be for the output line after the inverter.

 

Yes the two windings are primary and would be connected either in parallel or series depending upon the input voltage. (parallel for 120v, series for 240, for example).

I doubt that those two Transformers are connected in series but it is possible. Typically they be connected parallel to each other each performing a different function in the unit. They are connected to the AC input line ahead of any rectifiers.

If these are older and smaller units one Transformer could be for the input line ahead of the rectifier and the other could be for the output line after the inverter.

Thanks for the reply. It is a 2200VA unit and both transformers are identical if that matters.

I found a schematic for this unit but the board is a 0735 and mine is a 0734 rev 5. They seemed to make many revisions a year...

 

I took pics of the board (better pics) and it shows the 2 transformer connectors clearly. They seem to be in parallel and I'm trying to confirm the primary winding's .

 

Well, I can't answer that without an understanding of what you mean by "primary", because the use of that term is pretty relative! Most people mean the higher voltage windings by primary, but some mean the windings connected to the feed side of the circuit-as opposed to the load side.

Additionally, UPS designs do things with transformers that are very unusual, and I haven't really ever spent the time to work through their schematics to get a clear understanding of some of their games. They'd get rid of transformers if they could beat their inductive characteristics, and as R!F@@ implied, they sometimes use large, wound inductors.

I thought I might give you some quick help, but let's see what some others have to say.

 

I have used 650Va APC UPS transformers for countless projects.
One project was use 4 them for a power amp project. It works to this day but I say the darn thing is heavy. But it does provide plenty of power.

I cannot help OP.
He did not provide the resistance measurements I asked for.
He did not provide a complete transformer picture. I need to see the whole unit.
Plus it would be easier if OP has a auto transformer to do some tests.

 

I have used 650Va APC UPS transformers for countless projects.
One project was use 4 them for a power amp project. It works to this day but I say the darn thing is heavy. But it does provide plenty of power.

I cannot help OP.
He did not provide the resistance measurements I asked for.
He did not provide a complete transformer picture. I need to see the whole unit.
Plus it would be easier if OP has a auto transformer to do some tests.

I waited on the resistance measurements because I thought there was something wrong with my meter. I tested on an identical other transformer and the measurements were the same so it seems the meter is correct.

16awg side:
White/Black .6 - .7 ohm (initially read 1.3 for a second then would jump between .5 and .8 then settled at .6 - .7 ohm)
Blue/yellow ~.1 ohm - would bounce between 0 and .1 but reached .2 on initial connection

10awg side
White/Black - .1 ohm - stable

 

Hi,
I know this is an old post but seen quite of a lot of post about UPS transformers here. Thought I will share my experience. I salvaged one from a 700VA UPS. First of all, you can never find the details of these transformers with those useless labels on them, they are usually custom made for the particular manufacturer. Some of the things about UPS transformers:
1. The LOW voltage side is the one with thicker wires, usually a 2 wire or centre tapped 3 wire.They have lower gauge thick wires for higher current capability.
2. The HIGH voltage side has thinner windings for lower current.
If you connect the thicker wire side to mains you blow up the fuse or the transformer.

Yes, a UPS primary/secondary functions are reversed when it operates in the inverter mode but for the sake of identifying the leads quickly I've considered the transformer as part of battery charging circuit.

How to determine the primary 120V input wires? There are two ways:

1.This is the easiest way. Get a cheap 12VAC or 9VAC 500mA transformer and use the 12 or 9VAC to connect to the UPS transformer low voltage side(thicker winding with 3 wires, you can leave the centre wire.You have only two wires BLK/WHITE so its fine). You will get high voltage at the other side. Use a multimeter to measure the voltage across the four wires.Beware this will be higher voltage,70-100V if it's a 120V transformer(I assume your trans is 120V like mine) or 180-200V if it is a 220V transformer.

2.The second method is to connect the transformer to another UPS outlet. UPS's have an electronic overload protection.You plug in the wrong way you will trip the UPS and save the transformer and you can still figure out. Also, use only a 500VA to 700VA UPS anything above it will damage the transformer by overheating the thick wires and melting the varnish/enamel insulation. Why UPS? because make a mistake on the mains and its BOOM!!!.

Edit: ATTENTION: Do not PLUG the UPS into the MAINS and then do the second test. It should only be performed with the UPS unplugged from 120V/220V mains and UPS in test mode aka inverter mode or the UPS will be damaged instantly as R!f@@ has mentioned below.

 

They have higher gauge thick wires for higher current capability.

Check your memory buddy.
Lower AWG means thicker wires.
Higher AWG means thinner wires.

Why UPS? because make a mistake on the mains and its BOOM!!!.

Do not assume a UPS can withstand dead shorts on it's output.
At times it will trip and at times the UPS itself will fail.

Connecting mains require experience and care.
One need to use proper CB.

 

Check your memory buddy.
Lower AWG means thicker wires.
Higher AWG means thinner wires.



Do not assume a UPS can withstand dead shorts on it's output.
At times it will trip and at times the UPS itself will fail.

Connecting mains require experience and care.
One need to use proper CB.

Thanks mate for pointing out that error. I've corrected it. Of course if its one of those cheap Chinese UPS then it might damage the UPS. I tried mine on a 120 VAC 500VA APC BK500 and it worked perfectly fine. Since the lower voltage winding has lower AWG it will draw current like dead short so it will trip the UPS instantly, well unless you hold the test button deliberately(usually the power resistor and the 3 pin regulator IC will heat up and get damaged). But like you said its better to be safe than sorry later. I had got my UPS from a junkyard so it was okay for me. In any case, the first method is the safest.

 

I've heard of others doing the "UPS" method and having good results, and then later on a different UPS smoking it. It's all about current limiting and "inrush" characteristics (when you make a "wrong" connection, or a faulty condition exists). DC testing of AC devices has always been of limited value, but awareness of the differences, and approximations of correct values and offsets/multipliers will help acquire good results.

 

I've heard of others doing the "UPS" method and having good results, and then later on a different UPS smoking it. It's all about current limiting and "inrush" characteristics (when you make a "wrong" connection, or a faulty condition exists). DC testing of AC devices has always been of limited value, but awareness of the differences, and approximations of correct values and offsets/multipliers will help acquire good results.

============
I salvaged the transformer from APC (American Power Company) UPS
There are several very thick wires and normal (I call them thin wires).
The label has these labels:
430-0195 REV. 1
LS - A8477 - PT
Z150H E154515
CLASS B 130 (degree symbol) C (I assume it is Celsius)
LEI - 4 6A15
The above text/lable as they appear on the transformer.
Wires and their position:
Thin Black + thin White wires - most right upper corner
Thick Black + thick White wires - top center of the transformer
Thin Red wire - most top left upper corner
Thick Red wire - most bottom left corner
Thin Blue + thin Brown - most right bottom corner
I measured all the wires, but I include only the pairs that had any micro-Henry values :
Thin Black + White wires - most right upper corner = 2.494 uHy
Thick Black + White wires - top center of the transformer = 17.66 uHy
Thick White + thin Red wires - center of the transformer = 4.889 uHy
Thick Black + thin Red wires - top left corner = 5.060 uHy
Thick Black + thick Red wires - top center = 5.062 uHy
Thick White + thick Red wires - thick White, up center + thick Red, most left bottom corner = uHy
Thin Blue + Brown wires - right bottom corner = 23.09 uHy
================ Based on the values above, what is the function/reason for it?
When I used my VARIAC Transformer, I applied 120V to the thin Black+White wires (top right upper corner), here are the outputs I was able to measure (again, if I did not get any volts from other wires, I'm not reporting on them here) :
Thick Black + thick White = 15.5 V
Thin Brown + thin Black = 23.5 V
Thick Red + thick Black = 7.7 V
Thick Red + thick White = 7.7 V
Thin Red + thick Black = 7.7 V
Thin Red + thick White = 7.7 V
=============== I'm not sure why the thick Red + thin Red produced no volts, but last 4 lines, from the voltages I measured above, if I measured them against the other wires, there is this 7.7 V !
No voltage was if I measured other combinations!
============== This transformer is a puzzle that I need help with - I hope one og you might be able to help!
Thank you very much!
Tony

 

============
I salvaged the transformer from APC (American Power Company) UPS
There are several very thick wires and normal (I call them thin wires).
The label has these labels:
430-0195 REV. 1
LS - A8477 - PT
Z150H E154515
CLASS B 130 (degree symbol) C (I assume it is Celsius)
LEI - 4 6A15
The above text/lable as they appear on the transformer.
Wires and their position:
Thin Black + thin White wires - most right upper corner
Thick Black + thick White wires - top center of the transformer
Thin Red wire - most top left upper corner
Thick Red wire - most bottom left corner
Thin Blue + thin Brown - most right bottom corner
I measured all the wires, but I include only the pairs that had any micro-Henry values :
Thin Black + White wires - most right upper corner = 2.494 uHy
Thick Black + White wires - top center of the transformer = 17.66 uHy
Thick White + thin Red wires - center of the transformer = 4.889 uHy
Thick Black + thin Red wires - top left corner = 5.060 uHy
Thick Black + thick Red wires - top center = 5.062 uHy
Thick White + thick Red wires - thick White, up center + thick Red, most left bottom corner = uHy
Thin Blue + Brown wires - right bottom corner = 23.09 uHy
================ Based on the values above, what is the function/reason for it?
When I used my VARIAC Transformer, I applied 120V to the thin Black+White wires (top right upper corner), here are the outputs I was able to measure (again, if I did not get any volts from other wires, I'm not reporting on them here) :
Thick Black + thick White = 15.5 V
Thin Brown + thin Black = 23.5 V
Thick Red + thick Black = 7.7 V
Thick Red + thick White = 7.7 V
Thin Red + thick Black = 7.7 V
Thin Red + thick White = 7.7 V
=============== I'm not sure why the thick Red + thin Red produced no volts, but last 4 lines, from the voltages I measured above, if I measured them against the other wires, there is this 7.7 V !
No voltage was if I measured other combinations!
============== This transformer is a puzzle that I need help with - I hope one og you might be able to help!
Thank you very much!
Tony

I’ve had a few transformers from TrippLite and APC UPSs. One easy way to find the mains voltage winding is to apply 9-12VAC on the thick secondary side which is easily identifiable. The connect a multimeter to the other side and see which pair of them gone 115V.

 

I’ve had a few transformers from TrippLite and APC UPSs. One easy way to find the mains voltage winding is to apply 9-12VAC on the thick secondary side which is easily identifiable. The connect a multimeter to the other side and see which pair of them gone 115V.

OK, I done exactly what you asked for - NOTHING! Just sparks and no 120V output at all.
I tried all the THICK WIRES with combination of the thick red-black-white and measuring all the other "thin wires" - 0 V.
I also used a special thick copper wires, that are made from the same wire one uses in a car battery wires.
Any other ideas?
Thanks again.

 

I have two transformers from APC 1600 UPS systems that stopped working. I'd like to use them as a transformer for a HOT WIRE FOAM CUTTER project.

Transformer 430-9101-A Rev7
LEI-4 9516
Class 180(H)

I tried these instructions:
"1.This is the easiest way. Get a cheap 12VAC or 9VAC 500mA transformer and use the 12 or 9VAC to connect to the UPS transformer low voltage side(thicker winding with 3 wires, you can leave the centre wire.You have only two wires BLK/WHITE so its fine). You will get high voltage at the other side. Use a multimeter to measure the voltage across the four wires.Beware this will be higher voltage,70-100V if it's a 120V transformer(I assume your trans is 120V like mine) or 180-200V if it is a 220V transformer."

Does it need to be a 12v AC power source?

I hooked up a 12V DC regulated power supply to the thick Black wires (only two) one side side as shown in the picture. When I turn it on with the two black leads attached, the reset button on the back pops immediately.
So no success testing the leads on the other side.


???? THoughts???

 

The voltage source for transformer testing MUST be ab AC source because transformers do not work with DC. The good news is that it does not need to be a pretty ac source or any exact voltage, just one that you are able to measure. If it is 8 volts from one of those old toy computers that will work quite well, just remember that the voltage ratio is the same as the turns ratio. And always be careful to avoid both touching and short circuiting any wires. There can be both a shock hazard and a smoke hazard. AND that is even with the whole setup adequately isolated from the AC mains power.

 

MisterBill2:

Thanks for the AC clarification.

" Transformer wiring - Primary has 4 wire ends, secondary 2 ends"

To clarify, the AC insertion should occur on the side with 4 wire ends, is that correct. Was RoseRogue correct in Saying "using 1 & 2 as + and 3 & 4 as - , but wanted t check if that would be correct ..." ? Do you jumper 1 & 2 and 3 & 4 together?

 

MisterBill2:

Thanks for the AC clarification.

" Transformer wiring - Primary has 4 wire ends, secondary 2 ends"



To clarify, the AC insertion should occur on the side with 4 wire ends, is that correct. Was RoseRogue correct in Saying "using 1 & 2 as + and 3 & 4 as - , but wanted t check if that would be correct ..." ? Do you jumper 1 & 2 and 3 & 4 together?

Hi,
As MisterBill2 has already mentioned it should be low voltage AC supply to the secondary thick inputs. You can use those 9 or 12 or 15VAC adapters that come with computer speakers or something similar. Once you apply for example a 12VAC to the two thick secondary windings, use a multimeter in AC mode to cheack the voltage across the other four wires. You can also check out the continuity and resistance of the four wires with each other respectively to figure out how the windings are made.