Power Supply failure  

Re: Power Supply failure

Just wanted to add another name to the list of failed power supplies. Mine died last night during a 10 hour print. Talked with support today and am hoping them will send a replacement. US 110V

Re: Power Supply failure

Just wanted to add another name to the list of failed power supplies. Mine died last night during a 10 hour print. Talked with support today and am hoping them will send a replacement. US 110V

Wow this sucks. If this is truly a US 110V issue then I hope we can rally and get Prusa to consider a replacement that will work better in the US. I imagine that a have a pretty good customer base in the US that will eventually have a problem with this PSU over time.

Re: Power Supply failure

MK3 has independent CE testing from AKPtesting. It is attached. We have CE certificates from T-led for the PSUs too. They made all the PSUs for MK2, so they are pretty reliable. Please let us investigate and cooperate with the support. We did our homework before the release.

I haven't been able to find any data that shows that AKPTesting is a Notified Body legal entity within the EU / Czech Republic. Can you please clarify?

Given the Directives/Harmonized Standards referenced on your Declaration of Conformity, I am requesting a copy of the relevant formal Test Reports and other applicable data from the Technical File that shows that the Original Prusa i3 MK3 (and specifically the 24v power supply) is indeed in compliance with the stated Directives and Standards listed.

Thank you!

Re: Power Supply failure

http://www.akptesting.cz/

Re: Power Supply failure

Yes, I'm aware of the website.

Since PR referred to them (when J. Prusa stated "MK3 has independent CE testing from AKPtesting" on page 5 of this thread), I must assume that PR is not self-certifying for CE and relying on AKPTesting.

I would like to see the formal Test Reports, generated by a Notified Body, that shows evidence that the power supply and/or printer is truly in compliance with the Directives and Harmonized Standards as stated in the DofC.

If the power supply itself has not been properly tested by the supplier such that it can carry a Notified Body's certification mark (it may, I don't know...that's why I'm asking), then I would have thought extensive testing of the supply and/or printer would have been required by a Notified Body (and therefore a Test Report available, as part of the required Technical File) especially since the supply is coming in from outside the EU.

However, I cannot see anywhere on the AKPTesting site where they state that they are a Notified Body. I also cannot see where they are listed on the European Commission's list of Notified Bodies.

For example, the Meanwell supply someone listed on page 3 of this thread carries the CE mark...along with the symbol of TUV Rheinland, a Notified Body. There's enough data printed on that Meanwell supply to give me the right to call up Meanwell and request a copy of their Test Report (in this example, per the CB scheme) for that device to see how it was tested and how it performed, and be confident that they have a report from TUV to provide.

I'd like to see proof that the MK3's power supply can be similarly traced back to a Notified Body and the Test Report that they certified, whether they followed the CB scheme or something else.

Re: Power Supply failure

I now have 16 and a half days print time. And 650M filament. All PLA.

No issues what so ever with the stock PSU at this point. It doesn’t get hot at all.

The longest print I have done is 18.5 hours.

Again being in oz, we are on 240v. This leads me to the conclusion that this problem mostly effects 110v users.

So far I only have heard of one failure that was on 240V. I do have the 350w Meanwell supply and have printed all of the parts required for it should the need arise.

At this stage it looks like I won’t need them. Fingers crossed anyway.

Jason.

Re: Power Supply failure

That's why I'm asking...I want to see that the proper testing was actually done by a proper legal entity allowed to do so. It would show the voltages and frequencies actually used in a test.

I just did EMC testing with TUV Rheinland on a half-a-million dollar piece of equipment. It had to be checked under all applicable voltages and frequencies.. And that's just the EMC test, not even considering the other Directives and Standards that pertain to safety.

PR and AKPTesting are declaring that the product meets all the proper Directives and Standards. I'm asking for the objective test evidence that backs up that statement.

Re: Power Supply failure

That's why I'm asking...I want to see that the proper testing was actually done by a proper legal entity allowed to do so. It would show the voltages and frequencies actually used in a test.

I just did EMC testing with TUV Rheinland on a half-a-million dollar piece of equipment. It had to be checked under all applicable voltages and frequencies.. And that's just the EMC test, not even considering the other Directives and Standards that pertain to safety.

PR and AKPTesting are declaring that the product meets all the proper Directives and Standards. I'm asking for the objective test evidence that backs up that statement.

I agree this would be very useful indeed to see the actual charts used for the certification.

There is a very small % of people who have access to a oscilloscope and load tester to check out the quality of the PSU themselves.

Im sure it would make alot of people feel better if we had access to the info to see for ourselves that this PSU performs well.

Re: Power Supply failure

That's why I'm asking...I want to see that the proper testing was actually done by a proper legal entity allowed to do so. It would show the voltages and frequencies actually used in a test.

I just did EMC testing with TUV Rheinland on a half-a-million dollar piece of equipment. It had to be checked under all applicable voltages and frequencies.. And that's just the EMC test, not even considering the other Directives and Standards that pertain to safety.

PR and AKPTesting are declaring that the product meets all the proper Directives and Standards. I'm asking for the objective test evidence that backs up that statement.

I very highly doubt you are going to get that information. Based on the current reaction and communication from Prusa, it doesn't seem like they consider this a real problem. After all, thousands of printers have been shipped all over the world and only a small percentage seem to have this issue, all clustered in the US. Therefore, they have no interest (and, probably, desire) to release such internal information.

I, too, am worried about this as I am based in the US and despite the reported problems with the MK3, I keep coming back to it as my first printer (mostly due to perceived cost/value ratio). However, I hate the fact that the PSU is underpowered or underspeced for this application. I also hate that we (US-based customers) are in this position where the heart of the printer is faulty.

Re: Power Supply failure

Yeah, I don't think I'll see it either. But the whole point of CE is that somebody doesn't just get to make the subjective call about whether something is safe or not. If the product warrants it because of falling into a certain category, only certain legal entities can actually do the testing and state that. I don't think AKPTesting is one of those entities, and so I don't put any stock into their Declaration of Conformity until I can see the actual test data.

For example, going back to the Meanwell Power Supply SP-240-24 mentioned on page 3...here's the CB certificate for that supply that:
- states the supply truly meets IEC 60950-2,
- lists the Test Report number,
- and is signed off by TUV Rheinland, a true Notified Body that can LEGALLY author such a certificate and perform the testing.

http://www.meanwellusa.com/webapp/product/search.aspx?prod=SP-240&pdf=U1AtMjQwLUNCLUNFUi5QREY=&a=3

That took me less than 3 minutes to find.

I want to see the same thing for the power supply PR is using in the MK3. PR should have this handy.

Re: Power Supply failure

Hi Thomas,

As AKPTesting have been identified as the testing body, have you considered asking them for their accreditation information? and perhaps the Prusa accreditation...

regards Joan

Re: Power Supply failure

Hi Thomas,

As AKPTesting have been identified as the testing body, have you considered asking them for their accreditation information? and perhaps the Prusa accreditation...

regards Joan

I'd be willing a wager the OP is just trying to stir the pot.

I read a Google translated version of the AKPTesting website and based on a very quick read they seem legit to me but I'm not an expert in this area.

Re: Power Supply failure

sometimes the trick is to find the correct pot to stir! 🙂

regards Joan

Re: Power Supply failure

I'd be willing a wager the OP is just trying to stir the pot.

I read a Google translated version of the AKPTesting website and based on a very quick read they seem legit to me but I'm not an expert in this area.

Nope, not at all. J. Prusa made a statement and I'm asking him to back it up. There is no evidence on AKPTesting's site that they have any legal authority to certify testing, and no other regulatory compliance info is available on PR's site (that I can find), so I was just looking for some objective data to know that the MK3 power supply is safe to bring into my home.

You said you're not an expert, so I'm not sure what your opinion about "they seem legit to me" is based on. I'm not sure how to comment further on what you saw.

Either way, it doesn't matter. I had ordered a MK3, but am going to cancel that order. It was going to be my 2nd printer next to my TAZ 6. (and, by the way, Lulzbot lists their full BOM including the exact make and model of the Meanwell 500W power supply that is easily proven to be properly certified. That took about 3 minutes to find also.)

Re: Power Supply failure

I'm not sure asking for certificate will change anything. In my opinion they definitely got all the required certifications but don't put all this documents public (because PR don't have to or whatever reason PR have).
The power supply works like intended. In case of any failure, non-critical parts are melting and/or fuse is blowing. Once damage happened, you shouldn't replace the fuse or try it many times again. This is exactly when the funny part is starting with Smoke and Fire. That's why I don't think there is any issue in the power supply design itself.

The current PR power supply might be under-powered in certain conditions but this is something none of the certificates are checking which were mentioned in this thread.

Re: Power Supply failure

Hey everybody, the waiting list is about to shorten by one!!!! 🙂

Re: Power Supply failure

Nope, not at all. J. Prusa made a statement and I'm asking him to back it up.

How did Joseph respond to your request to back up the statement? Did you contact him through support or some other mechanism?

Re: Power Supply failure

I'm not sure asking for certificate will change anything. In my opinion they definitely got all the required certifications but don't put all this documents public (because PR don't have to or whatever reason PR have).
The power supply works like intended. In case of any failure, non-critical parts are melting and/or fuse is blowing. Once damage happened, you shouldn't replace the fuse or try it many times again. This is exactly when the funny part is starting with Smoke and Fire. That's why I don't think there is any issue in the power supply design itself.

The current PR power supply might be under-powered in certain conditions but this is something none of the certificates are checking which were mentioned in this thread.

A properly designed PSU will never melt any parts and have them burst into flames or otherwise explode before the fuse blows.

The fact that parts are blowing up before the fuse trips is a issue, that's how fires start.

Re: Power Supply failure

A properly designed PSU will never melt any parts and have them burst into flames or otherwise explode before the fuse blows.

Of course it can. Any part in the PSU can fail due to many different reasons. That's why there are regulations for the PSU enclosure and non inflammable parts are being used.

Re: Power Supply failure

A properly designed PSU will never melt any parts and have them burst into flames or otherwise explode before the fuse blows.

Of course it can. Any part in the PSU can fail due to many different reasons. That's why there are regulations for the PSU enclosure and non inflammable parts are being used.

Sure any part can fail, but in this instance it appears to be the same part blowing up consistently before the fuse trips, this indicates to me there is an issue with the design.