Products > Dodgy Technology
APC UPS, now with aluminum wire
jrmymllr:
--- Quote from: fmashockie on September 17, 2023, 06:44:34 pm ---Another follow-up to this topic. My work got in a couple of these APC UPS BR1000MS models. They are the pure sine-wave model also called the UPS back-up Pro. It is one APC's most well known offerings and it's likely one of the first UPSs to pop up on Amazon if you search 'UPS'. They are the exact same type that Dr. Carlson shows in his video. Anyway, I decided to HI-POT test the large AVR/inverter transformer when it is brand new. It fails miserably!! I can barely get it up to ~400-500VAC. This is terrible when you consider the formula for HI-POT testing which is Vt = (2Vw + 1000) where Vt = test voltage and Vw = working voltage. The max working voltage for this transformer is ~120VAC. So test voltage for this transformer should be ~1200VAC and it should be able to withstand that for a few secs. It cannot get even close to that!! And again, this is brand new right out of the box!! Here's a video I did showing the test below.
Now I've also tested the APC UPS BR1500G AVR transformers and they seem to be built much better. They will pass a HI-POT test at ~1200VAC. So if you ever have one of these BR MS models and want to fix it, you can grab one of these BR1500G transformers on eBay (I've seen them go for $20 used). You'll just need to replace the primary side lead wires to a thicker gauge and of course change the terminals to ring or fork style. I've done this repair on my own BR MS models and it works great!! If you have one of these BR MS models I would recommend doing this because this transformer will likely fail at some point and when it does (due to internal breakdown/shorting btw windings) it will draw massive amount of current and blow one or more of the inverter MOSFETs. This can happen in a very violent manner and could cause a fire.
Also, I know Dr. Carlson complains about the transformer winding being aluminum, but a lot of transformers use aluminum windings and they have no problems whatsoever. These are likely just made poorly with inefficient insulation. I'll have to cut one open to see how it looks inside! Hope this helps someone!
--- End quote ---
I just bought a BX1500M and then found all these complaints about newer APC UPSs failing because of the transformer. Needless to say it makes me a little uneasy. I have 3 older consumer grade APC units that are at least 19 years old and they just keep going. Plus a 25 year old Tripp Lite, again a consumer grade unit in a plastic chassis, that still works. I have serious doubts about the longevity of the new one.
Interesting how the BR1500G transformers seem to be better. I wonder what the BX1500M uses.
fmashockie:
I'm not an expert on this by any means and I have only sampled a small portion of these UPSs, but in my investigations, this problem with the transformers seems to mainly affect the pure sine wave models (economy priced) like the BRxxxMS units (1000, 1500VA). So you might be in the clear. The BX1500M is a simulated sine-wave unit similar to the BR1500G.
I don't know why the BR1500G (another simulated sine wave unit) has transformers that seem to be better quality. But the BR1500MSs that I have repaired with BR1500G transformers are still going strong without issue.
The simulated sine wave units are not without their faults though. For example, I have a BR1500G that developed an F06 error out of nowhere. The F06 error indicates 'relay welding' which means a relay is failing to open or close. There are 7 mechanical relays in the BR1500G. In my case, both the buck and boost relays for the AVR function were not working properly. This was due to a failed microcontroller. I did a thread on repairing this by replacing the micro. I uploaded the firmware there as well for anyone who needs it.
https://www.eevblog.com/forum/repair/repair-help-for-apc-ups-br1500g-f06-error/msg5019466/#msg5019466
jrmymllr:
--- Quote from: fmashockie on March 09, 2024, 03:49:17 pm ---I'm not an expert on this by any means and I have only sampled a small portion of these UPSs, but in my investigations, this problem with the transformers seems to mainly affect the pure sine wave models (economy priced) like the BRxxxMS units (1000, 1500VA). So you might be in the clear. The BX1500M is a simulated sine-wave unit similar to the BR1500G.
I don't know why the BR1500G (another simulated sine wave unit) has transformers that seem to be better quality. But the BR1500MSs that I have repaired with BR1500G transformers are still going strong without issue.
The simulated sine wave units are not without their faults though. For example, I have a BR1500G that developed an F06 error out of nowhere. The F06 error indicates 'relay welding' which means a relay is failing to open or close. There are 7 mechanical relays in the BR1500G. In my case, both the buck and boost relays for the AVR function were not working properly. This was due to a failed microcontroller. I did a thread on repairing this by replacing the micro. I uploaded the firmware there as well for anyone who needs it.
https://www.eevblog.com/forum/repair/repair-help-for-apc-ups-br1500g-f06-error/msg5019466/#msg5019466
--- End quote ---
I am very curious if my BX uses this crappy soldering and will call APC next week. It's likely they won't give me a straight answer for several reasons, at which point I have another plan.
How old was the BR1500 when it failed? And I'm shocked you were able to read the code off that micro! I assumed it would be protected since it's so easy to set that bit.
I really wish I knew what UPSs are built well. The expensive ones are probably good, and I read a lot of recommendations for Eaton.
fmashockie:
It is not so much the soldering in my opinion. While yes, Dr. Carlson did find that on his unit, on the ones I have encountered, it appears to be something internal that causes them to fail Hi-POT testing. The connections to the transformer are easy enough to check/fix - just recrimp them.
Yes I was quite surprised as well that the micro was not protected! But my BR1500G is also still going strong after that repair. It has to be ~5 years old. I definitely recommend replacing the batteries of these units on a scheduled basis (every couple years or so).
jrmymllr:
--- Quote from: fmashockie on March 10, 2024, 10:20:35 am ---It is not so much the soldering in my opinion. While yes, Dr. Carlson did find that on his unit, on the ones I have encountered, it appears to be something internal that causes them to fail Hi-POT testing. The connections to the transformer are easy enough to check/fix - just recrimp them.
Yes I was quite surprised as well that the micro was not protected! But my BR1500G is also still going strong after that repair. It has to be ~5 years old. I definitely recommend replacing the batteries of these units on a scheduled basis (every couple years or so).
--- End quote ---
The Hi-pot failures are something else, yes. But the fact that APC accepted these transformers and used them in production is simply negligent. That goes beyond a design error, or even cost cutting IMHO.
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