[Cerrado] Replacement PSU question  

Re: Replacement PSU question

There's a mains voltage sensor/monitor in the PSU, that hooks to the main board (this is your other cable).

So you would lose functionality of power panic.

Re: Replacement PSU question

Eh. You just design a new case and move the power panic board over. Pretty simple. No functionality lost. The board will hook to any 24v psu

Re: Replacement PSU question

Eh. You just design a new case and move the power panic board over. Pretty simple. No functionality lost. The board will hook to any 24v psu

You can do this fairly easily, I agree, however this is messing with mains voltages, as power-panic, monitors the mains going into the power supply. So as per normal internet warnings, and where I worked. "Danger, WILL result in DEATH."

Honestly, Prusa just needs to get their PSUs working.

Re: Replacement PSU question

Eh. You just design a new case and move the power panic board over. Pretty simple. No functionality lost. The board will hook to any 24v psu

Anybody know how this works?
I don't have a MK3 yet, so i couldn't take it apart and poke around in it's guts.

I'm a repair guy, and repaired electrical equipment for 15 years now, so i'm sure i can whip up a schematic and something on a perfboard fairly quick.

The MK2 PSUs weren't that good, with all the rattling and parts loose inside of them. (have 3 MK2s, in all 3 there were ferrits loose and on one a mosfet wasn't screwed to the housing) Had to open up all 3 of the PSUs and fix them manually. But at least they worked.
The MK3 board is just a catastrophic failure waiting to happen down a few weeks of usage from what i can gather.

I'll trust a Meanwell any day over Prusa's bottom barrel PSUs that they sell for +200% markup.

Re: Replacement PSU question

Eh. You just design a new case and move the power panic board over. Pretty simple. No functionality lost. The board will hook to any 24v psu

Anybody know how this works?
I don't have a MK3 yet, so i couldn't take it apart and poke around in it's guts.

I'm a repair guy, and repaired electrical equipment for 15 years now, so i'm sure i can whip up a schematic and something on a perfboard fairly quick.

The MK2 PSUs weren't that good, with all the rattling and parts loose inside of them. (have 3 MK2s, in all 3 there were ferrits loose and on one a mosfet wasn't screwed to the housing) Had to open up all 3 of the PSUs and fix them manually. But at least they worked.
The MK3 board is just a catastrophic failure waiting to happen down a few weeks of usage from what i can gather.

I'll trust a Meanwell any day over Prusa's bottom barrel PSUs that they sell for +200% markup.

There's no need to create a perf board project. The power panic board is attached to the iec socket and then screwed onto the plastic cover. It's only attached to the power supply with crimp on terminals and wire jumpers. Right on the switching terminals. It's an easy swap out. Just turning some screws.

Re: Replacement PSU question

89 dollars is a ripoff for that PSU. Good god. I'm still waiting on my replacement PSU after my second failure. My guess is even with the power panic chip, and the quantity they purchase, they pay no more than 20-25 dollars.

Re: Replacement PSU question

89 dollars is a ripoff for that PSU. Good god. I'm still waiting on my replacement PSU after my second failure. My guess is even with the power panic chip, and the quantity they purchase, they pay no more than 20-25 dollars.

Likely less than $15

Re: Replacement PSU question

So Prusa's (somehow prone to fail) 24V 240W PSU can be purchased here for a measly 100 dollar/euro.

https://shop.prusa3d.com/en/mk3-printer-parts/207-mk3-PSU-24v-240w.html

A really good meanwell 24V 320W (RSP-320-24 ) can be pruchased for just half of it, around 50 dollar.

Or a really good XKTTSUEERCRR 24V 15A 360W that CoreXY builders use for a long time can be pruchased with just 25 dollar.

Would the power panic funktion work with these as well, and just what is that black and white cable that's coming from the original PSU?

The power panic works with the meanwell (single test).

The pp board is attached to the plug receptacle in the base of the PSU. It has a single small wire that gets +24v from the PSU. The black/white pair come from that pp board and signal the einsy quickly when the 120/240 mains fail. This will be a bit before the 24v droops.

Re: Replacement PSU question

Has anyone measured the actual output voltage of the ps? The reason I ask is I have a pair of high quality 12v server supplies in series to power my lipo charger. The voltage is closer to 25v than 24v.

Re: Replacement PSU question

Has anyone measured the actual output voltage of the ps? The reason I ask is I have a pair of high quality 12v server supplies in series to power my lipo charger. The voltage is closer to 25v than 24v.

I have measured the output of my 1st replacement. It was 24.03 (low current, measured at the Einsy end). The Rambo can handle 12-28VDC, so you should be fine if they can supply the current.

At 25V you'll be putting ~4% extra current through the heated-bed, so make sure your supplies can exceed the 240W of the original supply by at least a bit.

Re: Replacement PSU question

The power panic works with the meanwell (single test).

The pp board is attached to the plug receptacle in the base of the PSU. It has a single small wire that gets +24v from the PSU. The black/white pair come from that pp board and signal the einsy quickly when the 120/240 mains fail. This will be a bit before the 24v droops.

Is there a schematic for the power panic board?

Re: Replacement PSU question

The power panic works with the meanwell (single test).

The pp board is attached to the plug receptacle in the base of the PSU. It has a single small wire that gets +24v from the PSU. The black/white pair come from that pp board and signal the einsy quickly when the 120/240 mains fail. This will be a bit before the 24v droops.

Is there a schematic for the power panic board?

Schematic can be found here: https://github.com/prusa3d/MK3_Power_Panic/blob/master/rev.04/power-panic.pdf

You can also find the board layout files here: https://github.com/prusa3d/MK3_Power_Panic/tree/master/rev.04

Re: Replacement PSU question

The power panic works with the meanwell (single test).

The pp board is attached to the plug receptacle in the base of the PSU. It has a single small wire that gets +24v from the PSU. The black/white pair come from that pp board and signal the einsy quickly when the 120/240 mains fail. This will be a bit before the 24v droops.

Is there a schematic for the power panic board?

Schematic can be found here: https://github.com/prusa3d/MK3_Power_Panic/blob/master/rev.04/power-panic.pdf

You can also find the board layout files here: https://github.com/prusa3d/MK3_Power_Panic/tree/master/rev.04

Thank you!
Will make one on a perf board for the meanwell when i get the PSU.

Re: Replacement PSU question

So Prusa's (somehow prone to fail) 24V 240W PSU can be purchased here for a measly 100 dollar/euro.

https://shop.prusa3d.com/en/mk3-printer-parts/207-mk3-PSU-24v-240w.html

A really good meanwell 24V 320W (RSP-320-24 ) can be pruchased for just half of it, around 50 dollar.

Or a really good XKTTSUEERCRR 24V 15A 360W that CoreXY builders use for a long time can be pruchased with just 25 dollar.

Would the power panic funktion work with these as well, and just what is that black and white cable that's coming from the original PSU?

The power panic works with the meanwell (single test).

The pp board is attached to the plug receptacle in the base of the PSU. It has a single small wire that gets +24v from the PSU. The black/white pair come from that pp board and signal the einsy quickly when the 120/240 mains fail. This will be a bit before the 24v droops.

My Mean Well has great capacitors. The printer stays on for 5 seconds before it finally loses power lol.

Re: Replacement PSU question

Has anyone measured the actual output voltage of the ps? The reason I ask is I have a pair of high quality 12v server supplies in series to power my lipo charger. The voltage is closer to 25v than 24v.

I have measured the output of my 1st replacement. It was 24.03 (low current, measured at the Einsy end). The Rambo can handle 12-28VDC, so you should be fine if they can supply the current.

At 25V you'll be putting ~4% extra current through the heated-bed, so make sure your supplies can exceed the 240W of the original supply by at least a bit.

They're 40A supplies, so don't think that'll be a problem. Thanks for your reply.

Re: Replacement PSU question

Hello,

i'am searching a bigger PSU too, and i found a cheap MeanWell PSU NES-350-24.

What do you think about it ? It has the same dimension like the original PSU but is more powerful. Are there any issues to use it with a MK3 ?

THX

Chris

Re: Replacement PSU question

i'am searching a bigger PSU too, and i found a cheap MeanWell PSU NES-350-24.

What do you think about it ? It has the same dimension like the original PSU but is more powerful. Are there any issues to use it with a MK3 ?

The Mean Well NES-250-24 is what I'm using, but the dimensions and more importantly mounting holes aren't the same. You'll have to print some sort of mount... I'm using this cover I made with the brace from this mount. You'll need to make some longer wires to connect the power supply.

Here's another option. I haven't tried it, but it should use less plastic and mount close enough to the original power supply to reuse the existing wires.

Re: Replacement PSU question

Are the Mean Well units as quiet as the Prusa PSU? (I'm thinking of the fan, not the horrible rattling... I assume they don't suffer from that).
Would the 350 be louder or quieter than the 240? I assume it has a bigger fan but probably runs less often?

Is it worth thinking of it as an "upgrade"? Anyone had a Mean Well PSU fail yet?
(My PSU died and I'm waiting for an replacement... just thinking about alternatives while I wait)

Pat

Re: Replacement PSU question

My psu just went out, and from reading here I should save myself the trouble and just get a nice mean well PSU. I'm a little new to all this, and just wanted to be sure I understood a few things before I move forward. First, the extra wattage is just extra capacity and won't harm my printer, correct? Second, swapping out the power panic board is easy? Does anyone have any instructions on how to do this so I can be sure I"m doing it right?

Thanks!