SoylentNews is people
SoylentNews
First, I debated whether to put this on stack exchange or here, but it seems like it is a tech question that suits this site fine.
Background
I have a room with a 115 V, 6000 BTU window AC unit plugged into one outlet. Then a bunch of electronics (~800 W measured) plugged into a 1500 VA, 900 W UPS plugged in to a second outlet across the room. Finally, I have two 50 W strands of Christmas lights in series (100 W total) I tried to plug into various outlets around the room.
Problem
The first problem is that whenever the room gets too hot, the compressor for the AC unit turns on and the Christmas lights will all flicker. This is not just an annoyance, because the first strand of lights I had in the room actually got burned out one by one, starting at the light closest to the wall outlet.
So I got another strand and was surprised to see the flickering happens even if they are plugged into the UPS (which does have an internal automatic voltage regulator). This made me concerned for the electronics plugged into the UPS, which includes a PC and monitors. However, I do not notice any flicker on the monitor when the compressor turns on. On the other hand, I have been getting some strange pc crashes lately (which would make some sense because only recently did it cool enough for the AC to not be running constantly) that may be related. This could also be due to installing a second gpu recently, etc though.
Questions
I have two main questions:
1) What is the best way to stop the flickering?
2) If the lights are flickering even when plugged into the UPS, should I also be concerned about the other electronics that are obviously also experiencing a momentary power reduction?
Some secondary questions:
3) Does it make sense to put another AVR between the UPS and the wall, eg something like this?
4) Is there something I can put between the AC unit and the wall to help?
5) This is a rental so I would prefer not to do any maintenance on the AC unit, but is this an issue you would report to the landlord?
Any ideas?
(Score: 2) by RS3 on Monday November 11 2019, @03:26AM
Yes, same here, I'm always finding and tightening loose lugs and wire terminal screws. Occasionally they're already really tight.
For those who don't do this stuff, on bigger wires you use a torque wrench, which measures how much rotational force you're putting into the screw / lug. It's always a lot more than I think it should be, but you follow the spec. I've been stunned at how loose I've found some. In one case, 208 3-phase 350A breaker, the resistance due to the loose lug heated up the wire and breaker so much it melted back the high-temp insulation (it was at least THHN if not higher temp rating) and tripped the breaker. Breakers will trip for both short-term peak current, and also longer-term heating.
I think some people just don't tighten terminal screws / bolts enough the first time. I'll do a bunch of them, circle back to the first one, and find it can tighten some more.
"Cold flow" is a term I've heard for metal deformation, and it makes sense.
All that said, I did a service call in someone's house where many circuits were intermittent. I found many of the neutral (returns) in the main breaker panel had been over-tightened so as to cut the wire off. So somewhere there's a happy medium.