i'm not, like, high or something, am i?

[solarbird]

godt

DAMMIT

Replacement new UPS is joining the previous new UPS by putting both 51V AC at 15mA

AND

8-20V DC (usually around 16V) at 16ma

...on the ground pin.

What the fuck, APC? This isn't like you.

Am I mad? None of the UPSes that don't trip GFCIs are putting current on the ground pin. Am I wrong in thinking this is a problem?!

It's like, I'm willing to put up with a little AC on the ground pin. There's a lot of way that shit can happen, a lot of inductive ways that say "this isn't really wrong, it's just not the tightest thing in the world and is losing some efficiency" and that WON'T trip GFCI. So I could kind of frown but tolerate that.

Not be fond! But... AC? Small amounts? Okaaaaaaay I gueeeeeeeeess...

But DC? Fucking DC?!

DC tells me it's not inductive. DC tells me it's past the fucking rectifier. DC tells me there is something broken in your circuit design or your component selection and makes me go, "How long do I have before this trips GFCI and throws my server rack onto battery backup again?"

APCs SHOULD NOT CAUSE POWER FAILURES, EVEN AT THE CIRCUIT LEVEL, EVEN IF GFCI.

(Particularly not if GFCI.)

I have three other APC UPSes that don't do this.

Both of the units I've received trying to replace the one that went bad do...

...just like the one that went bad started doing, when it started tripping GFCI.

What the fuck, team? Seriously, what do I need to do here?

Comments

[marahmarie]

Are you getting as far as you are in figuring out what's wrong by using a voltmeter or by some other method? Because I'm thinking if you're seeing a problem with DC then it's not plugged in when you're seeing that? And I mean no, I don't think you're high, just trying to picture what's going on here?

[solarbird]

...uh... no? I... okay.

I have a breakout box I built. It's for dealing with grounding issues like this. It plugs into the wall, standard three-pin plug.

It also has a standard two-outlet single-gang fixture. The hot and neutral pins are directly connected to the cord, and yes, I have electrician training, I'm not fucking up the polarity.

The ground pin of the outlet fixture goes to the hot pin of an medium edison socket, a.k.a., a medium light bulb socket. The shield of that socket is connected to the ground of the tool's power cord. This gives me access to the ground pin of any device that can be plugged into the tool, and with relative safety.

I have three devices I can screw into this socket. One is a dead short I built. This connects the hot and shield pins of the edison socket directly together, completing a normal ground connection.

The second is a resistive load with indicator, so that if something is dreadfully wrong with the equipment I am testing and it's shorting AC directly to ground, absolutely nothing bad will happen. It won't even blow a standard breaker.

("Resistive load with indicator" is a schmancy way of saying "light bulb." ^_^ )

The third device I can screw in exposes and elevates a pair of easily accessed 12-gauge wires with the insulation removed from the ends. One is attached to the hot pin, one is attached to the shield. This lets me securely attach alligator clip probes from a multimeter, so I can measure whatever the device is trying to put onto its ground pin against earth ground, in this case, voltage and current.

Here's a picture of those leads, if this helps:



It's a very simple device but rather useful in this context, because, well, ground faulting is the problem.

[marahmarie]

That is amazing. Good luck getting to the bottom of whatever's going on there!

[solarbird]

Well, I'm not going to open either New UPS 1 or New UPS 2, they're both under warranty and so on. So they're staying sealed up and it's a matter of figuring out what's going on from a more... customer service standpoint? Unless I can get through to someone who knows the engineering, which I have not yet been able to manage.

Old UPS ELDA, however, well. I've just found this little fucker:



...which is operating at about 10% of rated capacitance and also letting DC voltage through, which should absolutely fucking not happen, and pulling it from the circuit made me see hey! No more DC ground current, about 2% of formerly visible AC current. So hopefully if I replace that with a valid component, hopefully we'll be back in business with the old UPS!

Wish me luck.

[marahmarie]

I wish you luck! Glad to see you've made so much progress all-around. Hopefully you can get some good high-tier tech support that can actually help you troubleshoot/resolve the problems with your other UPSes or else get refunds on both.