Recent content by Ammarmalhas

It will take me some time but I will try to test with battery, I will report back here when I have something. Thank you for your advice and help.

Good info, I had no idea that PSUs prioritized their outputs. I will have to find a battery and try it sometime, but for now the SS relay solved the problem (so far). It must have been the connect/disconnect current (Inrush or whatever it is called) which I think is not there with SSRs?

But operating the mechanical relay (powered from a computer power supply (220/12/5/3.3v) without any load (no converters) connected, still produced interruptions to the monitor and to the USBs on the other completely separate electricity circuit! I did change the relays from mechanical to solid...

OK, i did not know that! So what can I do to prevent the interference and noise from affecting my USBs and my circuits in general?

I know the UPS's are 6000VA. Did not know there is a difference between W and WH! W and VA I know that much :-) Chassis ground are all OK everywhere. I do not know how one can get return through USB cables! USB cables and devices are not grounded. I have diodes on the USB cables to prevent...

OK I have done some quick reading and selecting these suppressor methods will be a hassle for me! I am not electrically savvy and i would rather buy me some ready solution. What relays do you recommend to pass 220V up to 1500W (7Amp) and operated with 12VDC that will not produce electric noise...

Can you please tell me some more about the use of surge suppression, diode or mov? What is an mov? How do I use these items? What sizes? Thanks.

Hmmm, my UPS's are 6000W each! What u say is absolutely correct, but the issue I have is even without the 220V side on the relay (no load on the circuits) and only the 12V operating the relay itself, I still get effects on one monitor (minor) and the USBs, all on a completely separate circuit...

Update 2: The wires from the UPS's are running in the same conduit. Would drawing from one line cause interference on the other? BUT still even without power on the relay , powering it with the 12V causes interference on the monitors and loss of USB on the other circuit

Update: Changing the mains to two different phases did not make a difference.

circuit 1http://files.engineering.com/getfile.aspx?folder=d2c5d461-194e-46db-919d-07272e4f4bf9&file=PC_Circuit_1.jpg

May I begin with an apology for hand-drawing the attached circuits, I am no wiz at drawing tools. I am facing a very strange (interference) case that has kept me busy for three days trying all I can think of with no use, My problem in short: I have two circuits as shown (1/2), when I operate...