SMPS and grounding

[octaviars]

4 hours ago, JohnSwenson said:

I have been doing other tests on networks and leakage, I will be making a post on that in a few days (probably in the thread on the Sonore forum).

 

Really looking forward to what you have found regarding networks and leakage? Do you by any chance also involved fiber optics in the test to see if that will solve all problems or will there just be another problem with the FMC at the end? I am about to go down a route of new network equipment and endpoint so the input that you share here will be usefull for me.

 

Another question have you done any measurments on linear PSU regarding the leakage when the DC minus is connected to earth?

[octaviars]

1 hour ago, Cornan said:

Since the Gopherts safety ground is not passed through to the case of the Gophert I am not sure it will work.

 

Are you really shure about that? If the case is not grounded then it should have a dubble isolated symbol. 

 

If you look at the picture of a Ghopert you see a ground connection screw next to the incoming ground wire from the IEC inlet. Have you measured between the case and the ground pin in the IEC to see if there is any connection? 

 

 

[octaviars]

9 minutes ago, Cornan said:

 

Yes, I am 100% sure. I have both got it confirmed from the manufactorer and confirmed it myself using a hand-held battery powered multimeter between safety ground pin as DC output and chassi.

 

Ok good to know that. Do you know what the chassi is connected to on the PCB? 

 

[octaviars]

1 minute ago, Cornan said:

It is the IEC fuse (soldered) as far as I can see.

 

No I mean the screw next to the green and yellow wire that is soldered to the PCB? If you look at other photos of Ghopherts there is a metal flange going up from the PCB which is attatched to the screw on the chassi. To me this did look like the chassi was grounded but if you have measured it I belive you so hence my question what the purpouse of connecting the chassi to the PCB if it is not for safety grounding?

[octaviars]

9 minutes ago, Cornan said:

The green/yellow cable is a ground wire ofcourse. It would be really dangerous without the IEC inlet grounded.

 

Yes but what is the ground used for on the PCB? If the chassi is isolated why would it be dangerous if there was no earth? 

 

I just want to know what they use the earth for if it is not connected to the chassi for safety reasons and if the chassi is not grounded it must be double isolated. I suppose the connect the filter capacitors to ground.

[octaviars]

45 minutes ago, Cornan said:

The safety ground connection should be there for personal safety if something goes wrong.

 

Yes that is of course the main purpose but if the chassi is not connected to safety ground how will it protect anyone if something goes wrong inside. If the unit was double isolated it would not have any ground connection.

 

This got really of topic so I will leave it for now and check when my own Ghopert arrives. 

[octaviars]

8 minutes ago, R1200CL said:

JSGT done simply:

 

 

I think this is as is as good as anything else. 

 

Just wrap the wire around the barrel of the Marvell 5,1 plug, and insert it. 

 

Anyone disagree ?

AWG 14

 

This is the easiest way of trying grounding the negative side of the PSU. I have a cableshoe that is 5,5mm inside that I put on the DC plugg before I inserted it in to my Netgear GS108 that feeds my music system. When my system is fully built I will make more permanent connections but to try it the cableshoe works really well.

[octaviars]

9 minutes ago, R1200CL said:

If no one yet hasn’t confirmed:

I just plugged LPS-1 into a 12V Netgear ProSAFE GS108.

And it works. 

 

Most network stuff have a DC/DC converter that will work at lower DC voltages than the PSU that came with it. At a serten point the converter will stop regulating and the switch turns of. I have a GS108 and I can test it with my adjustable DC aggregate if you would like to know how it behaves at serten voltages and what happens to the amperage.

[octaviars]

Did a quick test with my GS108 switch before your answer @R1200CL As you can se I have 4 connected ethernetcables and 3 of them were in use when I did the test.

 

12V

 

 

9V

 

 

7V

 

 

Stops regulating around 5,2V and starts back up again at 5,5V.

 

Amperage is 0,13A at 12V and 0,21A at 7V but that is just the DC/DC regulator doing what is does. If it is a good thing to run it on 7V for a long time I dont know.

[octaviars]

16 hours ago, R1200CL said:

Is it a Gophert you have ? (Yes, I see now from answer below)

I have one myself. Have not used it yet. The plan is to test it on my SonicTransporter i5, as two LPS-1 in series didn’t manage. 

 

 

Yes I have a Gophert but only bought it to have as a PSU to test equipment what volt and amperage they work with. Tested my NUC with ROON ROCK the other day and that worked well between 19-12vdc and 0,5-0,8A I will use linear PSU on my equipment. 

[octaviars]

On 2017-11-11 at 8:52 PM, JohnSwenson said:

Note that this is from leakage, if you stop the leakage from flowing through the cable, all this cable stuff above makes no difference.

 

Just some more food for thought.

 

John S.

 

So if you put a Netgear GS108 in the middle of the network and router, NUC with Roon ROCK and endpoint is connected to the GS108 with grounded PSU solve all leakage in the system?

 

My question is based on my thoughts about grounding more than one PSU (I have a 4 rail PSU that have separate ground for each output) and grounding all 4 will make all connected equipment have the same ground and no isolation between the connected equipment on the DC voltage.

 

As you write if leakage is stoped the used ethernetcable will have less impact and the use of ordinarie UTP cable is ok?

 

What are your thoughts on this @JohnSwenson? 

[octaviars]

40 minutes ago, R1200CL said:

 

Is those plugs really connected to the shield ? Did you measure ? The Vodka is not.

 

The old Supra CAT7 have the shield connected to the plugs so I think it is the same on the new CAT8.

[octaviars]

4 hours ago, sandyk said:

 Hi Alex

 I have a friend with a 300W HDPlex PSU that also owns an LPS-1

 I have forwarded this post to him and asked if he is able to check the actual output voltage of it's 12V rail.

IIRC, he also had a module fail some time back, and that later revisions provided some protection.

Do you know from these customers if their HDPLex PSU modules failed at the same time, with perhaps a series voltage regulator failure resulting in full unregulated output voltage to the load ?

 I believe that this may have happened.

 

Kind Regards

Alex K

 

I have the newest HD Plex 200W 4 rail PSU and I measured all outputs and they are what they are suppose to be.

 

As there are four different HD Plex PSU the old 160W and 300W and the current 200W and 400W so it would be good to perhaps sort out what modell of PSU that fried the LPS-1 @Superdad if you know that? I dont want to use the HD Plex if there are this sort of problems with them.

[octaviars]

Ok I see @sandyk just bought the PSU secondhand to use with ISP fiber, router, switch and NUC but it gets rather hot so need to see if it will work in the long run......perhaps just use the SMPS that came with the equipment and just ground the SMPS to my GS108 and be done with it

[octaviars]

6 minutes ago, sandyk said:

 

 I could be wrong here, but I think that the adjustable output may be the one more likely to fail if the output voltage is turned down close to it's lower adjustable limit, which would result in more voltage being dropped across it's voltage regulator, causing it to run much hotter.

 

I run the adjustable at 19V and around 1.5A so that wont be a problem. 

[octaviars]

3 minutes ago, sandyk said:

What do you +19V for ?

 

My Asus router runs on 19V.

 

I use 5V to ISP, 19V to router, 12V to switch and 19V to NUC with Roon ROCK. 

 

[octaviars]

3 hours ago, One and a half said:

For each 0V of each power supply, bring them to a common point, and from that common point, ground that connection, if you haven't completed this already.

 

I dont think I will do that I will only ground the 12V to the GS108 switch and keep the other ones floating as the PSU is linear and the only place I need a ground is at the switch to shunt away leakage on the ethernet. 

 

I talked to Paul Hynes about connecting all -0V to ground and he thougt that was not something he recommend as all groundplanes from the equipment would be shared and also noise from each component could spill over to another. 

 

I also think @JohnSwenson wrote somewere that only grounding at one place could be a good thing. And as I have no SMPS the only ground I need is at the switch to shunt out leakage from the ethernet.

 

So my HD Plex will get one grounded output to my switch GS108 and the other 3 outputs will be floating. 

 

My Paul Hynes SR4 feeding my SOtM SMS Ultra will also be floting.

[octaviars]

28 minutes ago, One and a half said:

Understand where you are coming from. If all the 0V are tied to ground at one point, the 0V are guaranteed to be the same potential. If any load creates an impedance leakage (high or low), that current returns to the source that's supplying it. Each current from the 19V or 5V supply will always travel back to the source, that's the way it works. There won't be a spill from one component to the other, of course if everything floats, now spill is a very likely event.

 

 

Well I can only refer to what Paul Hynes told me regarding his floating multirail PSU that he would not connect togheter all -0V as the whole meaning of having seperate windings on the transformer would be lost.

 

As I dont have any SMPS at all in my system the high impedance leakage is not something that I would need to worry about and as I got the GS108 smitch grounded all my network equipment is connected to that so the low impedance leakage will be shunted out that way to the grounded 12V at my HD Plex.

 

I am not arguing that this is the best solution and I might ground all my PSU rails but my understanding reading what @JohnSwenson have written about a system only having linear PSU and the right switch to shunt out the leakage the need for grounding all PSU is perhaps not so critical.

 

I will start of with just one ground when I rebuild my network but that might change over time.

 

I will use Ghent sheilded (JSSG loop) networkcables and my AC powercables are sheilded using Johns sheilding JSSG loop.

[octaviars]

26 minutes ago, JohnSwenson said:

Note that the grounding the special switch (in order to shunt the high impedance leakage from network SMPS) does NOT count as the one earth connection above. This ground IS galvanically isolated from the rest of the system by the Ethernet transformers, you should have a different single earthing point.

 

My system is a HD Plex linear PSU that feeds my ISP fiberconverter, router, GS108 switch and NUC with Roon ROCK. 

Ethernet goes to  Sotm SMS Ultra that is feed by a coming Paul Hynes linear PSU, from Sotm SMS Ultra I go to my dac that is double isolated so no ground and only linear PSU inside. From dac to amplifier with balanced xlr the amp is also double isolated so no ground. 

 

I have two 230Vac feeds, one to the network stuff and one to my audio stuff (PSU for Sotm, dac and amp). No filters or anything like that in the powerstrips.

 

My plan was to only ground the 12v feeding the GS108 at the outlet that feeds the HD Plex PSU but perhaps a second ground in the audiorack so that I have one groundconnection and I suppose grounding the PSU feeding the SOtM would work if the -0V in that is connected to USB ground. Then the DAC and amp would se that ground or am I wrong here?

 

The only connection between the two 230v systems  (network and audio) is the ethernet cable from switch to Sotm SMS Ultra. 

 

This is a jungle

[octaviars]

54 minutes ago, Superdad said:

7 of those 10 were from people charging their LPS-1 with an HDPlex power supply.

We can not cover under warranty failures caused by third-party "energizing"/charging supplies.

 

Do you know exactly what HD Plex it was? There are more than one model.

[octaviars]

35 minutes ago, Superdad said:

 

The 100W and 200W (though from photos of their interiors it is hard to believe that the newer model really has twice the output capability of the older unit).

 

I think the old one was 160W and all outputs shared the same -0V, the new one is supposed to be 4 seperated rails but in my 200W I can only see 3 outputs from the transformer and 3 rectifiers so I think 2 outputs share the same windings on the transformer. 

I suppose the electronics in your LPS-1 is rated at a 12vdc maximum but at what voltage does it fry the circuits?

 

I have not yet connected my HD Plex 200W that will power my ISP fiberconverter, router, switch and NUC with Roon ROCK but this problem with over voltage have me a bit concerned about using it. Most of the stuff I will connect have their own DC/DC converter so perhaps they are not so sensitive to a short overvoltage input?

[octaviars]

12 hours ago, Superdad said:

 

12V is the max we approve of for continuous input.  A spike of 18V or more will quickly fry one of our input regulators.

 

Was this during normal operation that the HD Plex fried the LPS-1 or did something break in them? Did the users use the12Vdc output or the adjustable 5-19,5Vdc output if you have that information?

[octaviars]

15 minutes ago, Superdad said:

If you have further questions about this matter, please write to me.

 

Ok, I will do that.

[octaviars]

On 2018-01-02 at 2:16 AM, sandyk said:

It also seems likely that some of the failures may have been due to users fiddling with cables etc. with the power switched on, causing a momentary voltage spike or even failure of the HDPlex.

The 19V Adjustable voltage rail being set to +5V (as some members did) with a reasonably heavy load such as a USB card etc. , would also have caused this module to get quite hot, and in some instances did cause the voltage regulator to go S/C causing >19V to be applied to the powered device, which was also irreparably damaged ! 

Repaired/returned  modules came back with overvoltage protection fitted.

 

I have tested my 200W HD Plex and to me it gets rather hot just runing around 0,5-1,5A on each of the four outputs and the variable set to 19V.

 

Larry wrote that 70 degrees is ok as operating temperatur but to me that is not ok in the long term as my will power network equipment 24/7.

 

The 19V and the variable 19.5-5V output share the same winding and rectifier so not four seperate outputs.

 

So the 200W model do have overvoltage protection from the begining? 

[octaviars]

Modded my Netgear GS108 today, easy to connect ground to the -0V inside the switch. From the threaded insert a ground cable will go to the outlet feeding my PSU that supplies the 12Vdc to the switch.