Meanwell MDR-100-24 power supply broken due to overheating - reliability ?

[Blue]

I have a Meanwell MDR-100-24 @ 230V that just broke down after about 20min of usage at around 26V at 2.9A (Potentiometer was used to turn up the voltage). It was quite warm/hot.

The device is rated for 4A and should have an over temperature protection.

Now, it makes a whining sound when pluged in again after cooling down and no output.

Are Meanwell powersupplies reliable?

Any idea what to check for a possible repair?

[Faringdon]

They are mega reliable...maybe yours just had some ESD damage.

[jonpaul]

junk from china
dead switch Q, drivers
j

[Stray Electron]

  I haven't used any of them for very demanding work but I've checked out probably about 70 of them after they used on board ships 24/7 for several years and all of them were fine. 

   Obviously they're not built to Hewlett Packard or Mil-Spec levels but they seem to be reliable. But your 100-24 may be an entirely different design and built to entirely different standards so my result may not be relevant.  I'll add that I've found with all of the Chinese built stuff (both mechanical and electrical) that I worked with that is built to it's stated limits (or less) only and you can not overload it. Unlike HP and others,  Chinese electronics also rarely includes any kind of overload protection so if you overload it in any way, spectacular things tend to happen.

  As soon as you saw that that PSU was overheating, you should have shut it down and found out why.

[Wolfram]

What type of load was applied when the unit failed? Did the load draw a constant current? How was the current measured?

[Faringdon]

how old is the PSU.
Is the fan still working?
Meanwell is from Taiwan.
They are probably the biggest supplier of PSUs in the world.

[ejeffrey]

That unit is a DIN rail mount unit designed for free convection cooling.  These types of supplies are normally installed in cabinets with a bunch of other equipment.  What was the ambient temperature inside the cabinet?  A supply like this could quite easily overheat at 75% load in a warm cabinet.

[Kjelt]

Meanwell PSU is in general quite reliable but not for loads that will deliver current back to them , they are only designed to be used in one quadrant.
Then they have different series also high reliability series, they use better brand higher temp elektrolytes.
I have seen them used in the field at 24/7 gate control and even in €0.5M PnP machines.

[floobydust]

It's got a 3-year warranty, send it back.
Could have failed due to blocked air vents, placing DIN-rail modules snug against the sides is a no-no. The unit's power output de-rates significantly above 40°C.
At 60°C it's good for 60% load or 57.6W or 2.2A at 26VDC. So "4A" rated... not really.

[Blue]

Thanks for all the answers.

I was testing a led system. The current was around 2.9A continuesly at around 27V. Current was measured with a clamp current meter. I placed the din unit flat on its side on a table. So only on one side the heat was able to escape.
It overheated and broke down. Never to be revived again.
Protection circuit inside did not its job of protecting itself.

According to the sticker on the box, I bought it in 2009, a while ago. It was never actively used - only sitting idle in a dry and dark wooden Ikea closet.

[nomead]

I have a smaller 40 W version of MDR-series. It's an interesting PSU, first switcher i've ever seen in which you can adjust the output voltage up to the over voltage trip. 
It resets if you return output voltage back to acceptable level and recycle power.

Does your supply still work at nominal 24 V?

[Swainster]

As a rule of thumb, electrolytics have a shelf life of 3 years before which they should either be discarded or at least reformed before being put into service. It would probably make sense to treat power supplies the same way.

We tried to source some XP power supplies for a project at my old job, and the supplier (might have digikey as it wasn't a particularly big order), came back to day that the only ones they had in stock had exceeded their shelf life - would we be willing to accept them? We declined.

[f4eru]

Yep. Typical failure of an electrolytic capacitor stored for too long.
They really need reforming after years of storage, especially when used at 230V, and especially Chinese caps, and especially Chinese caps from the 2000's

[wraper]

Yep. Typical failure of an electrolytic capacitor stored for too long.
They really need reforming after years of storage, especially when used at 230V, and especially Chinese caps, and especially Chinese caps from the 2000's

I really doubt it has anything to do with capacitors. In general you need to store them for decades without voltage applied before they start failing on applying power. Some low ESR caps bulged in storage after a few years, but it's more about capacitor plague times.

[floobydust]

OP should take it apart and do an autopsy. My first guess would be it failed due to electrolytic capacitors that dried out or needed reforming before jumping into service at full load.

[tunk]

Looks like it's made for convection cooling mounted vertically.
Putting it on the side may have led to sub-optimal cooling, and
if the temperature sensor is placed on the top, it may only have
measured inflowing air. This may have led to over-heating.

[f4eru]

I really doubt it has anything to do with capacitors.

Why doubt ?
Electrolythics are the single reason for the most failures on aged PSUs.

In general you need to store them for decades without voltage applied before they start failing on applying power.

Not really. Electrolytics start degrade(in the reforming sense) the moment they are switched off.
After a week, you can reliably measure a reforming current
After a month, it gets to be a significant pulse
After a year it starts to go in the territory of "low probability to blow the fuse"
After 10 years, you have a good chance of quick failure.
(This timeline is for 230V. In the US it is a nearly absent phenomenon, due to the huge margin on 110V for typical dual voltage PSU.)

All electrolytics have this, higher voltage are worse.
Some brands are like 10x worse, especially Chinese ones, because they don't have access to the advanced anti-corrosion formulas for electrolyt additives.
This is even worse in caps from the 2000's, but I got the same problem on modern ones.
I had to learn this the hard way.

[Black Phoenix]

All electrolytics have this, higher voltage are worse.
Some brands are like 10x worse, especially Chinese ones, because they don't have access to the advanced anti-corrosion formulas for electrolyt additives.
This is even worse in caps from the 2000's, but I got the same problem on modern ones.
I had to learn this the hard way.

They have access to such anti-corrosion formulas, but they choose to not use them since it is "extra cost".

https://youtu.be/SuJGXTFDqj8

Not related but if you watch just take a shot everytime profit is mentioned in this video...

As this most factories run such way, if it is extra cost and the end product works without such, then it is not used since it reduces the profit.

[floobydust]

I tried to follow ChongX, ChangX, ChengX etc. to see if this is one company or all knockoffs of knockoffs, or what.
Surprised to see many chinese electrolytic cap manufacturers go on the HK exchange, then they close down and flee once corruption charges come up. It seems to be a popular scam.
CapXon appears legit but are renowned world-wide as absolute pieces of shit capacitors. I notice massive lawsuits, they're still paying for the 2014 damages to Japanese cap maker  over HK$273,000,000 ref. pg.22 2020 Interim financial report so they can't just shut down to avoid the fines.
Very difficult to find reasonable quality capacitors.

[Swainster]

I tried to follow ChongX, ChangX, ChengX etc. to see if this is one company or all knockoffs of knockoffs, or what.
Surprised to see many chinese electrolytic cap manufacturers go on the HK exchange, then they close down and flee once corruption charges come up. It seems to be a popular scam.
CapXon appears legit but are renowned world-wide as absolute pieces of shit capacitors. I notice massive lawsuits, they're still paying for the 2014 damages to Japanese cap maker  over HK$273,000,000 ref. pg.22 2020 Interim financial report so they can't just shut down to avoid the fines.
Very difficult to find reasonable quality capacitors.

I have to admit to having a kit of those ChanX e-caps which I use for experimenting/prototyping, but I wouldn't consider using that brand for a permanent repair, or spec it for a production device.

Regarding the CapXon lawsuit, the damages are to a Japanese gas appliance manufacturer, which I assume was one of their main customers. https://www.palomaglobal.com/

[Kjelt]

Not only chinese capacitors.
It all depends on the design requirements and the actual environment they are used in.

[Siwastaja]

junk from china

As usual, arrogant and wrong "information" from jonpaul.

Meanwell, a Taiwanese company, is one of the most well regarded low- but not lowest cost power supply manufacturers. Might be manufactured in mainland China; just like almost everything from any brand.

Any company has failures every now and then. If it's a genuine product, work with your distributor/seller for a replacement.

EDIT: missed the 2009 remark. That's pretty old. Obviously it will be out of any warranty, like anything else.

[TimNJ]

I tried to follow ChongX, ChangX, ChengX etc. to see if this is one company or all knockoffs of knockoffs, or what.
Surprised to see many chinese electrolytic cap manufacturers go on the HK exchange, then they close down and flee once corruption charges come up. It seems to be a popular scam.
CapXon appears legit but are renowned world-wide as absolute pieces of shit capacitors. I notice massive lawsuits, they're still paying for the 2014 damages to Japanese cap maker  over HK$273,000,000 ref. pg.22 2020 Interim financial report so they can't just shut down to avoid the fines.
Very difficult to find reasonable quality capacitors.

I learned from my Chinese coworkers that the ChongX, ChengX, ChangX brands are all knockoffs of the OG "Chang" brand which is Changzhou Huawei Electronics Co. At least, that's what they think.

http://www.huaweiec.cn/en/.

We are using some Chang brand caps and see no problems. I mean, we are using their higher end series. They are actually not particularly cheap, even compared to other Chinese brands of reasonable quality, e.g. Aishi, Samxon, and so on.

I guess the original Chang brand must have had a lot of credibility (within China at least) to warrant so many ripoffs. Seems funny to me, as an outsider. At this point, if I was any of the aforementioned "X" brands, I would've changed my name about 15 years ago.

[wraper]

I've seen Chang caps in early 2000's, got to notice Chong, Cheng, ChangX, ChongX and similar much later. AFAIK currently ChengX has become quite popular and I've seen them is some not so cheap devices. So I guess it can be considered they grew out of knockoff status, but name reminds of its origins.

[floobydust]

"Changzhou Huawei Electronic Co., Ltd. is affiliated to Jiangsu Century Group which is a public company listed on Hong Kong Stock Exchange in name Tech Pro (3823.HK)"
... Accounting irregularities, losses, disciplinary action, de-listed...
Capxon International Electronic Company Ltd, incorporated in the Cayman Islands with limited liability. privatized, de-listed HKEX 2020/10/27 $0.60/share.  There are plenty of scam joint ventures.
Chong_X can be good depending on who you buy from. I find AiSHi are poor quality despite their pride. It's such a shell game.

In SMPS power supplies, caps are priced to the penny. It's common to undersize the parts as well.
LCD TV power supplies with 2 of 3 caps populated, and smaller diameter than the pcb footprint. So 3x1,000uF ends up being 2x820uF (54%) and of course the parts get trashed by the high ripple current. So a quality cap brand can fail due to overstress, abuse.
PC power supplies, I've never seen so many different makes/models of capacitors, all to save pennies yet make the warranty period.

I don't know what brand caps Meanwell used in OP's power supply, or how lean the design is. Even then, there are knockoffs of Meanwell to look out for.