APC 5KVA UPS with NMC 3 giving error; battery charger fault

khamosh

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Model: APC SURTD5000XLI-CC

So today, it started giving this error; Charger Battery Fault Exists and now it won't switch to direct AC mode.
When resetting it, it goes to AC mode for 5-10 seconds and when it detects the fault, it goes back to inverter mode and starts giving this error.

It is out of warranty. I received a quotation for an extended warranty a few months earlier when my 2 year warranty was about to expire, and it was ₹16,500, including GST, so I skipped it.

This was purchased from a relative for a considerably lesser amount and was using it for my gaming PC and a home NAS.

I opened it up. There was dust buildup (a lot of), so I cleaned it to observe any visible defects but couldn't see any.

I tried resetting it, but nothing happened.

I watched some YouTube videos [I watched the HINDI version] and figured out the charger section. I observed it twice, but still, no burst or leakage was found.

What should I do? Although, I live in a tier 2 city, I don't think these kinds of UPS are repaired here.

Sharing the PCB picture. If anyone can help, that would be incredible.


EDIT: Apparently, transistors Q730 has gone bad. How can I confirm this?
 

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Heisen said:
How do you speculate that these have gone bad?
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I saw a YouTube video of a Pakistani guy this morning. Got his Whatsapp number in the comments, I asked him on WhatsApp and got this reply: "Check fuses F3 and F4 with Q730 and Q731. These are used in the charger portion."

I checked them and replied with the readings, so he told me to replace Q730 with a similar specs transistor.

I want to get a second opinion now.
 
These can be checked in circuit but that will be little bit advance.

Usually it requires shorting base/gate pin of the transistor with emitter/source pin and observe voltage on collector/drain pin, the voltage should rise, then connecting positive supply on base/gate through a 1k resistor the voltage on the collector/drain pin should fall. These have to be done when the board is powered on. This is only one test that I know, there might be others.

Also if you somehow source an another working board like this, then yours can be repaired, it becomes real easy when you give a working board along with a non working board to a repair man, but I suppose chances of that happening is nil.

First you have to get the part number from the transistor, for that you have to remove the heatsink I think. Through this we can see what kind of transistor it is and we will also know the exact pinouts, then you can look for replacement.

You can also try finding the schematic of this board online, it will be helpful for the repair guy.
 
Heisen said:
First you have to get the part number from the transistor, for that you have to remove the heatsink I think. Through this we can see what kind of transistor it is and we will also know the exact pinouts, then you can look for replacement.

You can also try finding the schematic of this board online, it will be helpful for the repair guguy.
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I googled the part number and got its datasheet, its a 30A 1200v IGBT transistor. But, its of Q731 and I've to replace Q730. I think both of them are same.
I don't have access to Q730 and can't check its part number as its blocked by another component [transformer ig]

Also, this pakistani guy told me to replace the fuses F703 and F704
 

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So it's an IGBT, they are rare compared to the usual bjt and mosfets. I do see some replacements on mouser, but they cost between 500-1000 per piece.

This might help.

 
This is a very common repair for UPSs, most places replace them with pin-compatible alternatives that's rated for the same (operating) voltage if they can't find the exact part.

This is an extremely high quality UPS so I would pay the official service center for the repair. I know Vertiv does out-of-warranty repairs so APC should as well.

If I didn't already have an overkill setup, I'd be pestering you to buy this off of you, haha.
 
rsaeon said:
This is a very common repair for UPSs, most places replace them with pin-compatible alternatives that's rated for the same (operating) voltage if they can't find the exact part.

This is an extremely high quality UPS so I would pay the official service center for the repair. I know Vertiv does out-of-warranty repairs so APC should as well.

If I didn't already have an overkill setup, I'd be pestering you to buy this off of you, haha.
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My city's service center is temporarily closed and a third party is asking me to purchase an extended warranty for ₹16,500 [more than what I paid for this UPS] I'm not willing to spend this much, I'd rather get a pure sine wave inverter and battery.
Heisen said:
So it's an IGBT, they are rare compared to the usual bjt and mosfets. I do see some replacements on mouser, but they cost between 500-1000 per piece.

This might help.

Click to expand...
I got this replacement transistor [not exact match] for ₹220 but couldn't find the fuse. This Pakistani guy is an expert in these kinds of UPSs [see YouTube link provided earlier]. He told me to replace both fuses [F703 & F704]. Now, fuse is hiding between the two large capacitors and charger heatsink, so I can't see its part number. However, this paki guy told me to use any 3A 250V (rectangular) fuse. I couldn't find this in the local market.

Please link me to one.

Also, planning to get an inverter and battery.
A store quoted me ₹8k for Exide 12V 1625 and ₹20k for 230/250Ah [don't remember] battery. The shop owner said that it'll take a load of 1200W. Is this official specification? I tried looking up the official specs, but I couldn't find any mention of wattage on their official website.
 

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guest_999 said:

EXIDE INVERTERZ STAR(STAR12V1625) Inverter System

Get EXIDE INVERTERZ STAR(STAR12V1625) Inverter System at best price. Check out the details.
www.exidecare.com

1625VA means around 975W assuming 60% efficiency factor like in a typical ups. However, why do you even want to get exide ups when there are much more well known home ups brands like microtek & luminous.
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He was offering one from microtek too, lower priced than Exide [42 month warranty], should I consider that?
Although, He insisted on 80% efficiency in these, but I don't belive him

Edit: Found this when googled(see pic)
So, I can assume atleast 70% efficiency must be there
 

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khamosh said:
He was offering one from microtek too, lower priced than Exide [42 month warranty], should I consider that?
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Definitely, Microtek is far more established brand when it comes to home inverter but make sure it is pure sine wave model as non pure sine wave models are just a bit cheaper but because of extra commission the shopkeepers push them on unsuspecting/not knowledgeable customers. Another thing to consider is the after sales support, not all brands provide home visit support for home inverter in every location.

khamosh said:
Edit: Found this when googled(see pic)
So, I can assume atleast 70% efficiency must be there
Click to expand...
Looks alright.