SMPS and grounding

[sandyk]

Just now, rickca said:

If you're talking about MOV surge suppressors ... that's what the APC C5 is that gave me the whole problem in the first case!

 

 It seems likely that there may be a little more to it than just the use of  MOV/VDRs in the APC C5. 

Are you sure that it wasn't faulty due to previous high voltage spikes/surges ?

[rickca]

4 minutes ago, sandyk said:

 

 It seems likely that there may be a little more to it than just the use of  MOV/VDRs in the APC C5. 

Are you sure that it wasn't faulty due to previous high voltage spikes/surges ?

I agree with you, just having a device with MOVs shouldn't cause this kind of thing.  I was wondering myself if it was faulty due to previous surges.  It's plausible because I've had it for years, but the Protection On and Wiring OK indicators are both lit.  It's possible that those indicators are unreliable.

 

Question is what kind of fault would give me this problem with a SMPS with -ve output grounded?  How could it affect other outlets on the same circuit? 

[One and a half]

Just now, sandyk said:

 

 We can't always do what we would like to do in this area,. when renting.

The leakage of a VDR may be insignificant compared with transformer efficiency losses ?

John was quite specific in ruling out any power strips with surge suppression devices like Vdr, since they are usually connected to earth and they don't have gigohms resistance.  So there's leakage from them which then spreads. 

 

A 'large' isolation transformer can be hidden behind the equipment rack, about the size of a shoebox. 

Two of them would create a great base for a turntable,  they can weigh up to 30kg. Kinda ugly but functional.

[rickca]

1 minute ago, One and a half said:

John was quite specific in ruling out any power strips with surge suppression devices like Vdr, since they are usually connected to earth and they don't have gigohms resistance.  So there's leakage from them which then spreads. 

I better go back and review John's post.  I missed that point, thanks.

[One and a half]

Just now, rickca said:

I better go back and review John's post.  I missed that point, thanks.

Have a look here:

 

 

[rickca]

17 minutes ago, One and a half said:

Have a look here

I remember what John said about not using anything but a clean power strip with an isolation transformer.  I thought you were talking about my issue with a MOV device messing up John's recommendation to ground the -ve output of SMPS to eliminate high impedance leakage.  OK, I think I understand you now.

[sandyk]

33 minutes ago, One and a half said:

A 'large' isolation transformer can be hidden behind the equipment rack, about the size of a shoebox. 

Two of them would create a great base for a turntable,  they can weigh up to 30kg. Kinda ugly but functional.

 Garry

 In a Rental situation you will need to conceal such items, as Real Estate and Owner regular inspections are extremely unlikely to sanction any alterations whatsoever with the A.C. mains supplies, and will order you to remove them, no matter how safe they are, for Insurance reasons.

Incidentally, I don't normally connect VDRs from Active to Earth, only between Active and Neutral, as in a previous older house, even the typical high voltage capacitors used in filters to earth, occasionally helped to trip the ELCB.

Alex

[rickca]

No Topaz incoming here due to WAF and space.  Maybe get an Equitech unit when we get a real house.  Anyway, we better get back to the thread topic.

 

No worries about inspections here.  It's a joke, they let people BBQ on their balconies.  This is Florida.  It's against fire code, but there are no inspections.

[sandyk]

1 hour ago, rickca said:

Question is what kind of fault would give me this problem with a SMPS with -ve output grounded?  How could it affect other outlets on the same circuit? 

 

That's a bloody good question  !

 Perhaps Garry can answer that one ?

[sandyk]

24 minutes ago, rickca said:

No worries about inspections here.  It's a joke, they let people BBQ on their balconies.  This is Florida.  It's against fire code, but there are no inspections.

 

Lucky you ! At least the Gators are unlikely to attend BBQs on a balcony after smelling cooking meat !

 

I don't have that problem anymore, as I moved north with my family to a 4BR house they had purchased.

[One and a half]

1 hour ago, sandyk said:

 

That's a bloody good question  !

 Perhaps Garry can answer that one ?

None really. Take this situation. A 9V, 12V, 7V power supply each driving different devices. Join all three 0V together and then one cable to ground, done.

Some power supplies (rare event) have 0V bonded to the chassis of the PSU. If the bond is made again, no big deal, even if the PSU has a three pin AC plug, also no big deal, but those rotten 2 pin AC switchmodes, essential to ground the 0V.

[sandyk]

11 minutes ago, One and a half said:

None really. Take this situation. A 9V, 12V, 7V power supply each driving different devices. Join all three 0V together and then one cable to ground, done.

Some power supplies (rare event) have 0V bonded to the chassis of the PSU. If the bond is made again, no big deal, even if the PSU has a three pin AC plug, also no big deal, but those rotten 2 pin AC switchmodes, essential to ground the 0V.

 

 None would have been my answer too, but rickca is saying he has a problem.

It doesn't make much sense to me .

[One and a half]

8 minutes ago, sandyk said:

 

 None would have been my answer too, but rickca is saying he has a problem.

It doesn't make much sense to me .

No, really struggling to think why the Protection LED is on and grounding the output. If it were a short circuit, the SMPS shuts down. Some protection LEDs are always on, to tell you it's active, others it's a fault, so RTFM s'pose.

Or there's a cap to ground that's shorted perhaps on the input side, but now we are looking at equipment failure, can be anywhere now.

[oneguy]

On 11/17/2017 at 12:17 PM, MikeyFresh said:

In my video system I run short of available AC receptacles.

 

Which is the better approach in adding more ground shunts?

•  a so-called hydra JSGT with more than one device connected to the same AC plug, or
• A 3 for 1 AC adapter allowing one outlet to connect 3 JSGT equipped AC plugs

I'm thinking an outlet adapter like this one below is maybe easiest and most flexible to use?

 

You could just use the same outlet and wire in multiple grounds to it. I am running the ground from my ultraRendu and SU-1 to the same plug. Yeah yeah, I know it’s not green wire. It’s what I had available. 

 

[Boomboy]

^^^  looks good . i did the same today . 2 wires off 1 plug but , my network switch didnt work . il try another power board tomoz .

[sandyk]

10 minutes ago, Boomboy said:

^^^  looks good . i did the same today . 2 wires off 1 plug but , my network switch didnt work . il try another power board tomoz

 

 Didn't it work at all ?

Please keep us all informed, as another member had a failure due to earthing a supply.

[Boomboy]

7 minutes ago, sandyk said:

 

 Didn't it work at all ?

Please keep us all informed, as another member had a failure due to earthing a supply.

 

will do .. i even tried a separate plug each for the 2 devices i was wanting to do .. even changed the green / black thingy plugs in case 1 was faulty . raspberry pi worked but red light wasnt coming on so i put it back to normal .. switch had no power . il pop into bunnings and buy a standard 4 plug board and see how it goes ..

[oneguy]

34 minutes ago, Boomboy said:

^^^  looks good . i did the same today . 2 wires off 1 plug but , my network switch didnt work . il try another power board tomoz .

Which network switch (model #)?

[Boomboy]

its a netgear gs-105 box says year 2014 

[rickca]

7 hours ago, One and a half said:

Some protection LEDs are always on, to tell you it's active, others it's a fault, so RTFM s'pose.

OK I RTFM.  My unit was indicating that it was functioning properly.

 

Protection On Status Indicator When lit, the C5 is functioning properly. If the light is extinguished, the C5 has been hit by a surge and the protection circuitry may be damaged.

[watercourse]

On 11/12/2017 at 5:12 AM, octaviars said:

 

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.

 

This is what I am doing as well. Just happened to have the extra parts lying around that fit the 5.5mm barrel.

 

The reduction in high frequency hash is very noticeable. I may need to make some iZotope adjustments in A+ to take full advantage of this, but I just added the tweak last night and will let it sit for a while before doing anything more.

[rickca]

I'm really impressed with the effect of grounding the -ve output of a Mean Well energizing an LPS-1.  This is definitely worth doing.

 

It's more than I anticipated.  Certainly a lower noise floor, so you can hear low level details more easily and the music seems to flow more freely.  I'm just using it with an ISO REGEN.  Also, no dropouts at all with GI on.  I have no idea if that's due to the grounding.

 

I also got rid of my surge suppressor/power filter at the same time.  Somehow it was incompatible with grounding the Mean Well.  The combined effect was really remarkable.

 

Thanks, @JohnSwenson!

 

 

[tboooe]

Need some help...I am trying to do this grounding tweak to my LPS-1, however when I plug the grounding ac plug into my PS Audio P3 ac regenerator the LPS-1 does not power up.  If I remove the ac plug from the P3 the LPS-1 Powers up.  Any ideas?

[JohnSwenson]

42 minutes ago, tboooe said:

Need some help...I am trying to do this grounding tweak to my LPS-1, however when I plug the grounding ac plug into my PS Audio P3 ac regenerator the LPS-1 does not power up.  If I remove the ac plug from the P3 the LPS-1 Powers up.  Any ideas?

See the post right above yours, it seems there are some power conditioners that do not work well with grounding scheme, I have no idea why, I don't have any of these to try out, and personally I don't really want to get into testing such things right now. If the grounding doesn't work with the power conditioner and it does work when plugged into a regular (non-conditioned) outlet, then listen to both ways:

 

non-grounded SMPS plugged into conditioner, powering the LPS-1

grounded SMPS into regular outlet, powering LPS-1

 

Whichever sounds best, go with that.

 

John S.

[watercourse]

This shunt to ground tweak is sounding pretty great with the MeanWell and ISORegen, without making any adjustments to iZotope filters. The soundstage depth and imaging are pretty phenomenal.

Thanks @JohnSwenson!!!