Hello, I have SMPS Meanwell RPS 200.

I have same problem as in video

I removed XY blue caps that connect one pin of L or N line to GND.
But the effect (lower but) still is there. If I rotate power cord pins then it's fine (as you see from video was glowing both directions before).

There is no Ground, so I want this not happen as appliance GND will be connected to PC.

 

That supply is Class I and needs a safety earth. It is not designed to be safe without an earth connection.

 

Safe SMPS? Only transformer based PSU is safe, but who uses these nowdays everything is SMPS. Question is how to make neon lamp not glow both ways power plug is connected either way?

I have also tried laptop PSU with ground wire on low side (3pin plug vs. 2pin plug to laptop) and without, no difference. Neon lamp glows.

 

Yes it would.

 

That psu needs an Earth for the metal casing, there will be an X rated Blue Capacitor connected to the Mains Rectified Negative side to the Negative DC output side, and this will be connected yo the casing, this is causing the neon screwdriver to light up,..

 

That psu needs an Earth for the metal casing, there will be an X rated Blue Capacitor connected to the Mains Rectified Negative side to the Negative DC output side, and this will be connected yo the casing, this is causing the neon screwdriver to light up,..

As I said, I removed 3 blue X/Y type caps with one pin connected to Chasis, the problem remains.
"But the effect (lower but) still is there. If I rotate power cord pins then it's fine (as you see from video was glowing both directions before). "

 

It is not safe to use that supply without an earth connection for the metalwork.

 

That supply is Class I and needs a safety earth. It is not designed to be safe without an earth connection.

"RPS-200 is a 200W highly reliable green PCB type medical power supply with a high power density (21.9W/in)
on the 4 by 2 footprint. It accepts 80~264VAC input and offers various output voltages between 12V and 48V.
The working efficiency is up to 95% and the extremely low no load power consumption is down below 0.5W.
RPS-200 is able to be used for both Class 1 (with FG) and Class 2 (no FG) system design. The extremely III low leakage current is less than 130mciroA. In addition, it conforms to the international medical regulations (2*MOPP) and EMC EN55011, perfectly fitting all kinds of BF rated patient contact medical system equipment."

That said I wonder why neon light at all then?
I removed the Y caps and now the neon light only when phase is connected to neutral. Otherwise it is fine. But with leakage current is less than 130mciroA the neon should not light

 

(Some text removed for clarity)
That said I wonder why neon light at all then?
I removed the Y caps and now the neon light only when phase is connected to neutral. Otherwise it is fine. But with leakage current is less than 130mciroA the neon should not light

I use this neon lamp as a high voltage indicator in this power supply. It is clearly glowing orange when the power supply is on so I will be reminded to turn the power off before touching anything. The lamp only has 12.5 microamps DC flowing through it.

 

Get a Dvm and measure the voltage on the case to Earth and to Neutral, both AC and DC,...