APC UPS Open Ground on Taichi X670E

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   I have an APC 1500-Pro UPS with a new battery.

During testing,I turn off the 120V circuit breaker to the UPS, and the battery beeps accordingly.

This does not turn off the 120V test lamp connected to the UPS Battery Backup outlets, but it does shutdown the computer.

I have since learned that turning off the power also breaks the UPS ground ??I get an open ground reading through my outlet tester when it's plugged into the UPS Battery Backup outlets. 

In fact, I am unable to power on the computer through the UPS Battery Backup outlets unless I turn the breaker back on and the ground closes.

Is this due to the open ground? Is this normal?

Is there a way to solve this problem?

Thank you.

AMD Ryzen 9 7950X
Radeon RX 6600/6600 XT/6600M

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charles Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 Jun 2023 Location: Ashtabula Status: Offline Points: 180	Post Options Post Reply Quote charles Report Post Thanks(0) Quote Reply Topic: APC UPS Open Ground on Taichi X670E Posted: 25 Sep 2023 at 9:00am
	I have an APC 1500-Pro UPS with a new battery. During testing,I turn off the 120V circuit breaker to the UPS, and the battery beeps accordingly. This does not turn off the 120V test lamp connected to the UPS Battery Backup outlets, but it does shutdown the computer. I have since learned that turning off the power also breaks the UPS ground ??I get an open ground reading through my outlet tester when it's plugged into the UPS Battery Backup outlets. In fact, I am unable to power on the computer through the UPS Battery Backup outlets unless I turn the breaker back on and the ground closes. Is this due to the open ground? Is this normal? Is there a way to solve this problem? Thank you. AMD Ryzen 9 7950X Radeon RX 6600/6600 XT/6600M

charles Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 Jun 2023 Location: Ashtabula Status: Offline Points: 180	Post Options Post Reply Quote charles Report Post Thanks(0) Quote Reply Posted: 25 Sep 2023 at 9:29am
	The two question marks in the fourth line are typos. They should be either a period or a colon. Sorry about that.

charles Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 Jun 2023 Location: Ashtabula Status: Offline Points: 180	Post Options Post Reply Quote charles Report Post Thanks(0) Quote Reply Posted: 25 Sep 2023 at 11:41am
	Would just adding another ground wire between the computer and the UPS, like a T into the ground, work? I suppose this would be a lightening risk, but it can be fused. What's the deal? And I have a whole house suppressor that I forgot to add to this comment. Maybe the UPS unit is bad?? The previous battery was just causing shut offs, they were not even shutdowns lol. Maybe I should just get another unit, it's about 7-8 years old.

kerberos_20 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Dec 2017 Location: czech republic Status: Offline Points: 3657	Post Options Post Reply Quote kerberos_20 Report Post Thanks(0) Quote Reply Posted: 29 Sep 2023 at 4:44am
	both ground or neutral lines should be unchanged independently whether breaker is turned on or off if you get open ground with breaker off, then your breaker wiring is incorrect
	userbenchmark

charles Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 Jun 2023 Location: Ashtabula Status: Offline Points: 180	Post Options Post Reply Quote charles Report Post Thanks(0) Quote Reply Posted: 29 Sep 2023 at 5:19am
	Thank you for your response. The breaker wiring is correct. I get an open ground only from the back of the UPS device, and not from anywhere else on the residential branch circuit. I have since purchased a new APC UPS, and I'm hoping this will resolve the issue.

charles Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 Jun 2023 Location: Ashtabula Status: Offline Points: 180	Post Options Post Reply Quote charles Report Post Thanks(0) Quote Reply Posted: 23 Oct 2023 at 12:55pm
	Sorry if this comment is in the wrong place. It seems the motherboard and computer will run from the battery alone, but it seems to shutdown if the power (breaker) is shut off. It is a hard something, sleep, idk. But it definitely happens. However, if the breaker is off, and you boot from the battery alone, it is okay.

charles Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 15 Jun 2023 Location: Ashtabula Status: Offline Points: 180	Post Options Post Reply Quote charles Report Post Thanks(0) Quote Reply Posted: 23 Oct 2023 at 12:57pm
	I have not tried this with a disconnected RJ12 yet.

eccential Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 10 Oct 2022 Location: Nevada Status: Offline Points: 5050	Post Options Post Reply Quote eccential Report Post Thanks(0) Quote Reply Posted: 23 Oct 2023 at 7:03pm
	Ground is just ground. Not sure what you mean by "open ground." Normally, Ground is tied to the Neutral at the source, as a standard practice. Most quality UPS's also include isolating transformer, so the output Hot wire won't be directly connected to the input Hot wire. As for Neutral wire, I've no idea. Never really studied it. But I guess it's entirely possible that UPS also supplies its own Neutral wire when on battery power. Basically 100% floating AC. This could actually make sense, in case the AC power has gone wanky and one of the UPS's job is to protect the equipment. Ground should always be hard-wired to Ground, since it's a safety thing. Does your PC shut off, or go through proper shutdown sequence, when you flip the breaker off? If it shuts off immediately, I'd say your power supply is unable to keep the DC outputs going when there is a short glitch at the AC input side. You can try adjusting the UPS's sensitivity level to HIGH. All APC UPSs I know of have this control, but the adjustment depends on the model. HIGH setting can make it switch to battery more often, if AC power is even slightly inconsistent, but I think it might help with the glitch duration. Not sure. Another possibility is that your power supply just doesn't handle the simulated AC power (stepped AC). I believe only the SMART UPS class outputs true sine wave output under battery, at least from APC brand. But I haven't kept up with the brand specifics in ages. If it goes through software-initiated shutdown sequence, I'd think there's a software involved, whatever that may be. Edited by eccential - 23 Oct 2023 at 7:06pm