Replace fan on APC Smart-UPS 3000XL (SUA3000RMXL3U)

[5mall5nail5]

Hi all - long time youtube watcher, new-comer to the forums!

I have a server rack at home that has an APC Smart-UPS 3000XL in it.  It's a 120v UPS that I run.  Recently, a fan inside starting making an annoying noise.  Now, I've read that the unit is not "user serviceable" but these are fans - how hard could it be?  I am cautious because I know there is an inverter inside, etc. to charge the batteries and all.  So, my plan would be to disconnect the battery module, disconnect service power, open the top lid, and see if I can deduce which fan is making noise.  I could, perhaps, even power it up on the bench to hear the fan with the lid off.  Either way, is this insane or anything?  I am suspecting there are either 120v fans or 12v fans inside - a read on a forum that it's dangerous but I can't deduce if its a true risk or if someone is overly cautious.  The internal temperature indicated by the network management card is 68F so no worries there.

I've built wiring harnesses for race cars, wired 240v 50A circuits for my welder/plasma cutter, etc.  Am I being ignorant here?

Attached a youtube video for reference to the sound



Thanks all!

[dschnur]

It's a *really* simple repair.   Remove it form the rack, there are quite a few Phillips #2 screws on the top, remove them, then there is one more screw holding in the fan.  It's in a sheet metal bracket and it's pretty obvious how it goes back in.  The fan is standard off the shelf part, so make note of the exact part number, look up the specs, then order a new one with the same specs and pop it in.  Be careful of the heat sinks inside that are close to the fan.  They can bite.  If you want to be even safer, remove the battery and unplug it for a few days.   I don't remember if that model had a bleeder resistor, but better to be safe.

[5mall5nail5]

Thanks dschnur!  So, I managed to get over to the facility with said APC unit.  So, it's not as easy as I expected:

2016-09-22_10-32-27 by Jon Kensy, on Flickr

APC Fan Replacement by Jon Kensy, on Flickr

In the second image above you can see that the blue arrow points to the fan I need to replace.  I am going to replace all fans, ideally.  The main fan that is making a ton of noise (feels/sounds like a failed bearing) is the fan that the blue arrow points to.  There is a bracket that both of the fans in that area are screwed to.  I cannot reach the screws without removing the bracket, but the bracket comes out easily I think by design.  Problem is, there are cables going through the bracket (small red arrows).  The cables screw to what appear to be heatsinks indicated by large red arrows.  I can't get the bracket and fans out without unscrewing those large cables at the large red arrows.  Are those heatsinks grounded?  Will I get shocked touching that?  I would assume a heatsink is grounded as it looks like transistors also rest on it with their base, but that's a terrible assumption.  The tranformer looking things on the left of the first picture are where the large cables source from.  I can't really discharge the capacitors based on the access shown.  Any advice?

[Monkeh]

Those screws look dreadfully like simple plastic pins you can pull out.

[5mall5nail5]

They do look like pins I can remove.   Hm.  That would be convenient.

Is the heatsink electrified?  Would seem strange but I am not a UPS guy.  Assuming I do need to remove the bracket holding the fan... can those large white and black cables be unscrewed?

[Monkeh]

Not going to be electrified if you remove the batteries..

Just pop the pins and ease the fan out, nothing else should need touching.

[5mall5nail5]

I may have trouble reaching the bottom pin(s) but will try.  Worst case, the heatsinks will not have energy on them if the batteries are removed (which they will be)?  Could I then remove the screws holding the black and white cables on?

[Monkeh]

Be aware of possibly charged caps, but yes, you can remove those cables if you must.

You won't need to, get a long thin knife and pop those pins off.

[pinyoro]

I have worked on UPS'S for nearly 20 years. Mostly large ones from 20kVA to 1 MVA and larger parallel systems. Disconnect batteries and mains supply. Wait 10 minutes for capacitors to discharge. I am not familiar with this UPS so you can still check for DC voltage if in doubt. Disassemble taking pictures to aid with assembly.

[Rasz]

this fan will be 48V, so will voltages on the caps

if you want to learn whats going on in an ups like this I highly recommend series of videos by knurlgnar24

[Monkeh]

this fan will be 48V, so will voltages on the caps

Except it's not.

[Rasz]

this fan will be 48V, so will voltages on the caps

Except it's not.

its 24v? :0
so 24v fan, 48v on caps

[5mall5nail5]

Just wanted to let everyone know I made the repair and did not die.  I had to remove the two large cables screwed to the heatsink in order to get to the pins that hold the fans in:



I measured the potential between the heatsink and chassis and nothing was there with the batteries removed.  I still taped up the ends of the cables so as to not short while moving the fan bracket around.



The fan connectors are the type where you jab the wire beteween a V and it cuts the insulation.  Not my favorite, but didn't feel like getting creative there.  I did a continuity test between the pin of the connector and the wire at the fan to make sure it was contacting.



I replaced all of the fans in the unit in this manner.  It purrs quietly again!

Here are the fans I used after looking up the original parts and matching specs - I purchased from Mouser:

• Large fan:  Qty 1   664-AD1224UB-F51-LF 1 1 0 19.000 19.00
  MFG Part No:AD1224UB-F51-LF
  ADDA DC Fans
  US HTS
• Smaller fans:  Qty 2  670-OD802524HB 2 2 0 9.150 18.30
  MFG Part No:OD8025-24HB
  Orion DC Fans
  US HTS:8414596590 ECCN:EAR99 COO:CN

Now she hums quietly into the night again!

[Monyker]

Just did this, this week.
I used:

• Qty 1 Orion OD8025-24LB (Mouser p/n: 670-OD802524LB)
• Qty 2 Sunon PMD2412PTB3-A.(2).GN (Mouser p/n: 369-PMD2412PTB3A2GN)

Presumably it was the large fan's bearings that had failed, but I didn't want to take the time to test, or have to open the chassis again anytime soon. The fans were pretty cheap. I salvaged the connectors from the old fans and use a small flat-blade screwdriver to push/terminate the wires from the new fans.

After removing the UPS from a rack, I disconnected the big connector/wire that goes to the battery array. 24 hours or more later, I started removing some of the screws from the wires that pass through the fan bracket, to make it easier to pull the bracket up and remove the old fans.  When the screwdriver touched one of the screw heads (black wire with connection point on logic board), there was a poof / bright spark!    Thankfully I was touching only the handle (not the shaft) and didn't get zapped.  It seems the UPS has some capacitors that can hold a decent charge for a long time. I don't know what would have been the best way to discharge, but any future diyers should take note / be warned! I don't think that would have felt good had I been touching the driver shaft.

Put everything back together and the UPS is working well, thankfully! No more obnoxious fan noise and the replacement fans are working well.