Power Set up for ungrounded outlets (rental apartment)

Great, thanks!

 

jea48, I've seen wires run in the original GAS PIPE....... Which the building from 1880 definitely still has in the walls & ceilings. The house I grew up in was built in the 30s & had live feeds of gas capped off in the ceilings @ the pancake box

 

Yup, fire protection. (Rats gonna eat—and there are something like 2 million of ’em.) Anyway, this is the kind of stuff I meant by “unreliable grounding method”—thanks, @jea48

What would it mean to have a neon tester fail, but have a multimeter succeed, in finding a ground?

Also, is it correct that reversed-polarity AC receptacles prevent hot wires and component fuses from meeting—and thus imply safety concerns?

 

The plug in tester will not show OPEN GROUND if the Hot and Neutral are reversed.

Post #10:
jea48 said:
On the reversed hot and neutral outlet.
When you plug in the tester do you get only the org light for reversed polarity or do you get the red and the orange lights lit? I just ran a test using my plug in tester. I bench tested a duplex outlet with the hot and neutral reversed. With hot and neutral reversed and ground wire connected both the red and orange lights lit. (HOT /NEU REVERSED). I then disconnected the ground and the red light went out. Only the orange light remained lit.

By chance do you have a multi meter? If yes set meter to AC volts auto or above 150V. Because the hot and neutral are reversed insert one test lead probe in the bigger of the two mains slots/contacts and the other test probe in the equipment ground U shaped contact hole. Make sure you make a good contact on both contacts. If you have an EGC earth ground you will measure 120V nominal volts. You can also use the metal supporting back strap or the wall cover plate center support screw/hub for the ground connection.

With reversed AC polarity the equipment AC fuse and switch would be fed from the AC mains neutral conductor. In the event of an overload in the equipment the fuse will still blow. The fuse is still in series with the closed circuit. No different than the early days before the polarized two prong plug. You had a 50/50 chance of plugging in a piece of equipment with the fuse and switch on the AC mains hot conductor.

Throw in the mix the safety EGC (Equipment Grounding Conductor) then there are a few scenarios where reversed AC polarity could cause problems in the event of a ground fault. For one with the hot conductor directly feeding one side of the power transformer winding and there was a ground fault to chassis on the other end of the primary winding a few things could happen.

1) If the ground fault was before the load side of the switch and the switch was open the piece of equipment would still be powered up. Circuit would be completed through the EGC back to the neutral conductor in the main electrical service panel.

2) If the EGC is open and a ground fault were to happen on the load side of the switch and the switch was open the chassis would be hot, energized. Same if the fuse was blown the chassis would be hot.
As a rule when an EGC is connected to the chassis of a piece of equipment the power supply B- /signal ground of the audio equipment circuit is not connected directly to the chassis. In many cases through a low ohm resistor. Well if the EGC is open then the chassis is hot, 120V will be present on any wire interconnects signal ground that are connected to the ground faulted equipment.

Of course IF that were to happen... IF...

 

Ok, so I got my multi meter out today and did some quick tests.

The outlet I would like to plug my Zero Surge into that produced the Red and the Orange light on my tester plug tested at 120 volts through my multi meter with the pos prong on the pos side of the outlet and the neg prong on the ground.
It also tested at 120 V with one prong on each side.

All of my other outlets test at 120V with one prong on each side but don't do anything if you have one prong in the ground.

And really none of them tested at 120 V they're all at 117.

 

So only one outlet is grounded?
Weird

did you try hot to screw?

 

Hot to screw also 117 V, on that outlet.

Nothing on the others

 

There's nothing wrong with 117V. Measure the voltage at the wall outlets above the counter tops in the kitchen.

The outlet with the EGC ground is probably on a different home run BX. Or the outlet is up stream from the ones without an EGC.

Turn off the breaker that feeds the outlet you want to use that has the EGC ground. Check for voltage to make sure it is dead. Next check the outlets without a ground for voltage. Are they dead or still live?

What else is on the convenience outlet circuit, that you want to use for your audio system? With the breaker turned off walk around and check what else is dead. Check for ceiling lights as well that are dead.

 

I don’t think that’s unusual for Brooklyn on an 80-degree day. Not sure what neighborhood you’re in, but power in Greenpoint can be a little erratic.

As a comparison, here are the last three days:



And here’s an especially low-voltage (for us) week in mid-July:



I wouldn’t be surprised if you were to measure something different than 117 tomorrow (and the next day…)

And I’d definitely trade a steady 117 for our occasional peaks of 125-126.

 

There are only 3 outlets in this whole apartment and they all measured 117V. I'm not real worried about the dip under 120 as I know that to be normal.

The outlet that I want to use is the one that measured 117 with one prong in the hot and one in the ground, and also 117 with one in hot and one in neutral. Does that mean this outlet is grounded, and not hot neu reversed??

I have to look around the basement of the building to figure out where the breakers are. I'm somewhat curious if this whole apartment is on one circuit?

Right now, plugged into the same outlet I'd like to use is an extension chord going to an AC window unit with a power strip coming off that powering my computer equipment.

 

/ / / /

Scroll down page to the image of a 5-15R duplex receptacle.
https://www.se.com/us/en/faqs/FA156527/

You stated the plug in polarity/ground tester shows the hot neutral is reversed. Therefore the branch circuit Hot conductor is connected to the neutral contact on the duplex receptacle. The branch circuit neutral conductor is connected to the hot contact on the duplex receptacle. Correct?

 

So I guess I tested wrong after looking at that diagram. The right side, which should be hot, does nothing with one prong in the positive and one prong in the ground. The left side, or neutral side, shows 120 with one prong in and another at the ground. So it does seem like the polarity is reversed, right?

 

If the longer slot shows 120 to G or the screw it is reversed.

 

That is the case indeed. I believe I will just make the polarity reverser as I love the idea of not messing with any of the wiring, plug the zero surge in and be done with it.

 

It sounds like you know what you are doing but I might have an electrician take a look at it.

You can't tell if the others are reversed since there is no ground.

Be careful.
Plug a lamp in, turn it on.
Kill the circuit (lamp goes off) and confirm with the meter.

 

Buy a good quality plug and female cord cap. Hubbell are pretty good.

https://www.amazon.com/Hubbell-HBL5266C-5-15P-Black-White/dp/B081K21MZ9

https://www.amazon.com/HUBBELL-WIRI...29453&pd_rd_wg=Psef0&pd_rd_i=B00DJUH7XG&psc=1

 

And after you build the "polarity reverser" plug it into the wall outlet and plug the polarity/ground tester into the female receptacle cord cap. If you did the job correctly the tester will show CORRECT.

 

Will do, thanks! Any tips on where to get the 14AWG chord? I used the Home Depot link you provided but when I go to checkout it says it's not available to ship. I could buy somewhere locally or order elsewhere. It seems like it may be tricky to buy less than 25' but I guess I could make another high quality "stinger."

 

Any hardware stores close? If yes you might try calling them. Of course Home Depot sells it buy the foot but I'm not sure how far you would have to travel to get to the one nearest you. You also might check an online outlet.

Got an eBay account?

SOOW Portable Cord 3 Conductor Rubber Insulated 600V -Choose AWG Size and Length | eBay

1 ft 14/3 $1.10 + tax. Free shipping...

 

Awesome, thanks for that. Just ordered off eBay.

 

Still waiting on my wire from eBay but I went to Lowe’s yesterday and picked some 14/3 up (they only had 300v). I went ahead and wired up the polarity reverser and the test light reads “correct”.

I think I’ll build another 600v reverser and keep this 300v reverser and plug the less important stuff I have (not stereo equipment) that’s in the other outlet - am I correct in thinking that this equipment should be relatively protected by a MOV type surge protector?

For now I’ll plug the zero surge into it and play my stereo equipment and swap it out to the 600v wire when it comes- hopefully it’s ok for now with 300v (I assume whatever extension it’s on now is probably something like that)

 

300V is fine. A lot of cheap to medium priced Listed extension cords are only 300V.

Should be good to go. The conductivity of the EGC is unknown though.
See my post, post #19.

Line to neutral will not be a problem. A line to neutral connected MOV will absorb a transient voltage surge/spike.

 

Thanks! So while we don't know the conductivity of the EGC a surge protector should protect just fine. Just out of curiousity- would a mov still work with the polarity reversed? As in just plugged straight into my wall where the polarity seems to be reversed, without the polarity adapter I built?

 

Just wanted to follow up on this- I built the polarity reversing cable and connected it to a ZeroSurge with isolated outlets and a custom 15' cable to run it to my stereo. Maybe not surprisingly there was a notable sound quality increase then from before when I was just running without the zero surge and on a power strip coming out of the reversed neutral outlet. Not like crazy changes or anything, but even my non audiophile, usually not caring partner noticed a better sound quality after the change. Thanks everyone here for all the help and I'm quite satisfied.