HDMI blinks when UPS switchs voltage

Question

I have an RX580 and two monitors; one connected to the HDMI output and the secondary to a DVI-D port through a DVI-D to HDMI adapter. The PC and the main monitor are connected to an UPS and the secondary monitor, that also is a TV, is connected directly to AC mains.

Around here the mains is 220AC and when the voltage drops to 208V the UPS change its internal transformer coil to compensate the output voltage and some times the secondary monitors goes black for about 5 seconds and in some situations, when the secondary monitor tries to reconnects to HDMI, makes the main monitor goes black too for a couple of seconds. It seems like the UPS generates some kind of EMF spike or so.

There's something that I can do to avoid or at least reduce this effect?

Answer 1

As implies in @John post the issue is highly unlikely to he EMF but rather the transfer time of the UPS switching to/from mains.

There is not much you can do about this without changing/adding hardware. The most correct approach would be to change to (an unfortunately much more expensive) type of UPS - the double conversion UPS @gronostag mentioned.

Other (less likely to work/less optimum options/mitigations)

• It is also possible that you could replace your existing UPS with another one if the same type but focussing on reducing the switching time.
• You could try move your devices onto another electrical circuit. It is conceivable you have something which is drawing a lot if power on the particular circuit its plugged into. This could be pulling the voltage lower for longer tipping the scales.
• Depending on your country laws infrastructure you may be able to complain to the electricity provider. It sounds like they need to upgrade their equipment as its out of spec. In many countries the power output requirements are legislated - and their output is breaking the law.
• If you have a long extension cord feeding your devices you might be able to improve things by getting a heavier duty one - heavy duty extension cords have lower resistance/power loss - especially under high load. The longer the cable the higher the loss.

Answer 2

You need a true UPS (a unit that always supplies power from the battery). Simple consumer units do not always do that.

Eaton, APC and others make true UPS units.

Then anything powered by the UPS will not blink at all.

Devices connected to the AC Mains and not UPS may blink in a brownout and will blink off in a short (or long) power outage.

Make sure all your computing devices and also your UPS are properly grounded to AC Mains or earth ground.

I have an APC true UPS and the network gear and main computer connected to it survive power outages and brownouts very smoothly with no glitches at all.

I trust this helps.