Power supply smoking -- HELP PLEASE!

[john_100]

as the data sheet for the S-350-48 doesn't indicate that it can be used in parallel , I would look at the PSP-300 supplies

http://www.meanwell.com/search/psp-300/psp-300-spec.pdf

Meanwell Power Supply Products


otherwise why not use one power supply for one or two servo's
depending on the load ?


one thing to watch with multiple power supplies is the small leakage currents
that can add up to a level that can give you an unexpected shock

I've got the T shirt !!

I would connect the common negative outputs to earth

In the day job I have used and repaired switch mode power supplies
that are "hot swoppable"
the power supplies are designed to work in parallel and still
work correctly when one is changed with the power on !

http://www.trcelectronics.com/Meanwell/pdf/rcp1000.pdf



John

[mactec54]

john_100

There has been no trouble with this before, there are more than 2,500 packages sold & in use, put together with the 3/4 power supplies in parallel, no cap are needed

Ideal is a Single power supply, Dmm is offering a single power supply, but the cost is almost double for a single 1000W power supply, To get a single 1000W power supply at the same cost as the 3 is the problem but is being worked on

[mactec54]

firstyear

I just did some numbers & you should only be using a max of ( 3 ) of these Power Supplies
in Parallel, The fourth will be over load, your system is a 20amp max & with the ( 4 ) power supplies this will give you around 30amps

Remove the fourth power supply & you will be running

[john_100]

Hi Mactec54 ,

as you have proved with so many power supplies used in parallel

Firstyear must be unlucky to have a faulty power supply

even if a single 1000W power supply cost the same as three 350W supplies
three power supplies that work in parallel would be the the better option

keeping a spare 350W supply is less expensive ! If you need the machine
for business and not a hobby


John

PS the circuit I posted was an alternative for any one
that has power supplies that don't work in parallel

[mike_Kilroy]

Mac, perhaps it would be useful to explain why you state 3pc 350watt power supplies are required to power 3pc 400watt power supplies on a cnc machine rather than 1 (I could argue that about 1pc rated about 600 watt max is the correct size).

[mactec54]

mike_Kilroy

The peakpower for these 400W AC servo motors is around 800W, so Imax *48 = 800W, Imax = 16~17A

So firstyear will need the 3 power supplies to run his system, could he use (1) power supply, yes at around 1000W would be about right for the job, but will cost a lot more for the (1) power supply

[firstyear]

mactec54, mike_Kilroy, john_100, Al_The_Man, TrickyCNC, doorknob and epineh

First up I'd just like to say a massive thankyou to you all for all your help - You have given a newbie the courage to fix the problem with insight and knowledge beyond his hope and years!

I bit the bullet, prepared for a sacrifical P.S; started from scratch and hoped for the best.

sequence of events..

* I hooked up 1 P.S only - all ok

* I hooked up 2 P.S only - all ok

* I hooked up the 2 P.S and bridged the 48VDC V+ & V- connectors - all ok - holy CR@P it's working!? ooooooh....

* I hooked up the 3 P.S and bridged the 48VDC V+ & V- connectors - preapared for a bang, but nothing sweet nothing !! it's working!!!

Even though I will only be using 3 P.S's....

-With confidence riding high I hooked up the 4th P.S (now known as smokey the bandit) to the circut for sh/ts n giggles

Called some help over expecting a bang and winced as I flipped the switch..and...

it's working perfectly!!!!?????? WTF?
it's humming along nicely

Only thing I can say is that something was loose somewhere? We checked and tripple checked that nothing was loose the first time, but I guess we missed it??

Here are the pics of all 4 working in parallel.

After this hiccup I'm wondering if it's better to go for a single P.S? I have found a reasonably cheap one on Ebay.. It would be great if you could have a quick look at it and let me know what you think?

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

I'd look at buying it and using the current 4 P.S's until it arrived (couple weeks) and then selling the 4 that I have. Might be able to break even?

[firstyear]

Hi guys,
The power supplies are all up and working, but make a buzzing noise - is that normal?

[mike_Kilroy]

mike_Kilroy

The peakpower for these 400W AC servo motors is around 800W, so Imax *48 = 800W, Imax = 16~17A

So firstyear will need the 3 power supplies to run his system, could he use (1) power supply, yes at around 1000W would be about right for the job, but will cost a lot more for the (1) power supply

Good to hear you are up and running Firstyear!

Ok on your design methods Mactec; I see now why you call for the higher wattage supplies. Like transformers, oversizing does not generally hurt, so your scheme of course works too; I'll leave it at that and back into the woodwork....

[mactec54]

firstyear

No they should not be making a loud noise that you can hear, unless the fans are running

The 1000w power supply on ebay will only support a max of (4) of the servo motors, you would need 1400w to do the (5) axes set up you have

I still think that you should only be running a max of (3) of the power supplies wired in Parallel as that is more than what you need to run the (3) XYZ Motors

So take the 4th one out & see if they are still making the noise you are hearing

[Al_The_Man]

Go with the Linear supply advice in post #24. You won't regret it.
Especially with servo's.
Al.

[gslcnc]

One thing I don't see in this thread (did I miss it?) is, what are the motors rated at? voltage and current, please (or Watts if current missing)? The load is what determines the size of the power-supply.