Hey all,
the topic of Macs and UPS systems have been discussed many times in different threads here. However, I haven't been able to find a current thread containing my exact issues and concerns so thought I would start a new thread.
I have been having very frustrating issues over the last few months of random flickering in my apartment, and APC UPS systems always switching to battery and back ( randomly even on low sensitivity settings.)
I own a late 2015 27" 5K iMac, that has been the main target of protection.
I've done extensive testing and process of elimination, as much as possible as I don't own, but rather rent.
I've had maintenance check the breaker, check outlets, I've gone through process of elimination of unplugging all devices in the general area, between living room, and kitchen (bedroom, bathroom not effected)
The UPS model being used at this point was the APC 1500VA BN1500-M2. I would exchange for a new unit because I kept thinking I was getting bad units. It would be a day or 2, or even a matter of hours, then the random clicking and cycling would start again (again, sensitivity setting didn't matter.). The units are a simulated sine wave vs a pure sine wave UPS. The cycling was bad enough to cause power fluctuations in the apartment from living room to kitchen area (mainly flickering lights, and when I had it the oscillating fan would slow down too as under too much load.
I finally discovered the problem happened when either the iMac was plugged into the UPS (either side, or connected on the same circuit as the UPS). I returned the last APC unit yesterday to Office Depot, went to Best Buy, and got the CyberPower 1350PFCLCD pure sine wave unit, adjusted my sensitivity to low, and so far everything is quiet. My desk lamp may still flicker a tiny bit once and a while while the Mac is running, but so far none of the bad drama has taken place. I was concerned the iMac might have a power supply issue, but it runs fine and doesn't exhibit any strange behavior unless combined with one of those APC units.
It's also never been subjected to any surges or dangerous electrical conditions. If there were a bad storm coming, I would always shut down and unplug from the wall for extra measures of protection.
I did read various places, that while Macs will work with a simulated Sine wave UPS, they prefer pure sine wave.
By the way, my apartment complex was built in the late 60's so it's older, however outlet testers and ground testers have always shown proper wiring, and no faults. The power has always been reliable, other then in bad storms. It's only shown strangeness after combining the Mac and a UPS. If it's just the Mac on a surge protector, nothing was abnormal, if it was just the UPS without the Mac plugged in, also OK. So there has to be something going on between the Mac and a non sine wave UPS, as I mentioned, the problem seems to have gone away after getting rid of the APC and going with CyberPower.
I know this was a long post, but wanted to provide as much information in detail as possible.
I would be curious of feedback, because none of the other threads I've looked at discuss my exact issues.
the topic of Macs and UPS systems have been discussed many times in different threads here. However, I haven't been able to find a current thread containing my exact issues and concerns so thought I would start a new thread.
I have been having very frustrating issues over the last few months of random flickering in my apartment, and APC UPS systems always switching to battery and back ( randomly even on low sensitivity settings.)
I own a late 2015 27" 5K iMac, that has been the main target of protection.
I've done extensive testing and process of elimination, as much as possible as I don't own, but rather rent.
I've had maintenance check the breaker, check outlets, I've gone through process of elimination of unplugging all devices in the general area, between living room, and kitchen (bedroom, bathroom not effected)
The UPS model being used at this point was the APC 1500VA BN1500-M2. I would exchange for a new unit because I kept thinking I was getting bad units. It would be a day or 2, or even a matter of hours, then the random clicking and cycling would start again (again, sensitivity setting didn't matter.). The units are a simulated sine wave vs a pure sine wave UPS. The cycling was bad enough to cause power fluctuations in the apartment from living room to kitchen area (mainly flickering lights, and when I had it the oscillating fan would slow down too as under too much load.
I finally discovered the problem happened when either the iMac was plugged into the UPS (either side, or connected on the same circuit as the UPS). I returned the last APC unit yesterday to Office Depot, went to Best Buy, and got the CyberPower 1350PFCLCD pure sine wave unit, adjusted my sensitivity to low, and so far everything is quiet. My desk lamp may still flicker a tiny bit once and a while while the Mac is running, but so far none of the bad drama has taken place. I was concerned the iMac might have a power supply issue, but it runs fine and doesn't exhibit any strange behavior unless combined with one of those APC units.
It's also never been subjected to any surges or dangerous electrical conditions. If there were a bad storm coming, I would always shut down and unplug from the wall for extra measures of protection.
I did read various places, that while Macs will work with a simulated Sine wave UPS, they prefer pure sine wave.
By the way, my apartment complex was built in the late 60's so it's older, however outlet testers and ground testers have always shown proper wiring, and no faults. The power has always been reliable, other then in bad storms. It's only shown strangeness after combining the Mac and a UPS. If it's just the Mac on a surge protector, nothing was abnormal, if it was just the UPS without the Mac plugged in, also OK. So there has to be something going on between the Mac and a non sine wave UPS, as I mentioned, the problem seems to have gone away after getting rid of the APC and going with CyberPower.
I know this was a long post, but wanted to provide as much information in detail as possible.
I would be curious of feedback, because none of the other threads I've looked at discuss my exact issues.