But as I noted, it's not likely to make a difference which way you connect it.

Yes OK electrically, but it is not observing current safety wiring regulations.

 

Yes OK electrically, but it is not observing current safety wiring regulations.

True.
But with the case grounded there would only be a possible shock hazard if the safety ground connection were lost.

 

As already stated, the center with the green and yellow is the safety ground.
Since you can not connect to a plug as it is shown, you need to separate the three a bit.
I think that Mr Chips called them right in that post. so you are all set.
Given that one purpose of that extra "safety ground" wire is to trip the circuit protection if any accessible conductive part of the appliance connects to the line, you will be safe. AND indeed, the neutral side goes to the wider pin of the plug.

 

I'm of the opinion that it doesn't matter. If it did matter then they would have used cable that color codes the other two conductors. If the wire has no colors (except for ground) then how could even they wire it up correctly?

The people assembling the unit would have been staring at exactly what you are and there's no way they could distinguish one side from the other (unless they used a ohm meter but that sounds far more risky than just using color coded wires.

I suspect the unit switches both conductors on/off not just one.

 

Take a look here too

https://www.reddit.com/r/electricians/comments/mtkbi9/_/gv0agrc
and this

https://www.reddit.com/r/DIY/comments/1binvo9

 

I'm of the opinion that it doesn't matter. If it did matter then they would have used cable that color codes the other two conductors. If the wire has no colors (except for ground) then how could even they wire it up correctly?

The people assembling the unit would have been staring at exactly what you are and there's no way they could distinguish one side from the other (unless they used a ohm meter but that sounds far more risky than just using color coded wires.

I suspect the unit switches both conductors on/off not just one.

It DOES matter .

As said earlier, the fuse must be on the LINE and go before the switch, among other safety concerns.

 

I would say it SHOULD matter, first for the fuse reason, but you never know how is the wall socket wired.. so it... doesn't ?!

The original question was is it possible to determine hot/neutral of the device using only multimeter... so the answer I would say is NO. The fuse is the best way to determine it.
MAYBE if you know the internal circuitry, and there is some EMI filter between HOT and GROUND you could measure that. But in your case I would say no..

 

I think in short it's going to take you gaining access to the internal power connections. That should answer which is HOT and which is NEUTRAL. The ground - you already know which that is.

You said you don't have access to the internal's. Then nobody is able to use the AC. It's going to take the work to determine which is the correct wiring. I don't think there's a good way of determining with any accuracy which is hot and neutral via a test meter of any kind I can think of.

 

Connect the cable with the writing on the side to LINE (to the narrow prong, copper color).
Connect N to the wide prong, labeled W in the plug diagram, the screw is usually silver colored.

View attachment 347472

View attachment 347469

Since there is no ribbing on the exterior of the cable I've seen printed or inked markings on the Neutral or Negative leads. I've seen all black 2 conductor with white dash marks on one of the two conductors indicating (should the home holbiest need to know) typically either the negative or the neutral. I've also seen printing such as in the picture to POSSIBLY (I said "POSSIBLY"!) the neutral. I'm hoping others will confirm or debunk this statement, but if I had no choice but to proceed I'd use the printed side as the neutral.

A further example of wire identification such as speaker wires in a clear sheathing, one wire is bare copper while the other is (I think Tinned or) nickel plated. In such cases I'd assume the nickel plating is meant to indicate a polarity. In speaker wiring polarity is important because two speakers on the same line, one hooked up correct and the other backwards - the two speakers would tend to phonically cancel each other out.

I think - and someone correct me if I'm wrong - the printing on your cable indicates Neutral. I know this disagrees with @MrChips but ask anyone on this website - I've been wrong before.

 

I would say it SHOULD matter

"Should" - yes, it matters. For sure it matters. Even if: (next quote)

for the fuse reason, but you never know how is the wall socket wired.. so it... doesn't ?!

I've been shocked MANY times because of an improperly wired socket or plug. I lived in a house with old Knob & Tube wiring. The home owner thought AC meant it didn't matter. He half upgraded some of the wiring (poorly done at that) which before I knew about K&T wiring in the walls he inadvertently mis-wired a plug or a light socket. This is why you turn off the breaker - or remove the fuse as in the case of K&T wiring - before you THINK something is de-energized. A mis-wired socket is no reason to think it doesn't matter.

Out of convenience a former owner of my present home figured AC meant black and white didn't matter either. During a home improvement he accidentally cut the wires. It was more convenient the way they got severed was to wire back the two wires that meant he didn't have to stretch the wires to remake the connection. He wired Line & Neutral backwards. Black to white and white to black. THEN ANOTHER former owner decided he wanted to upgrade all the outlets to three prong. Not having a ground he decided to connect white and ground together so that when you plugged a tester in it LOOKED correctly wired. Here's what happened when I took ownership of the house: I plugged my computer into one outlet and my printer into a different outlet. When I went to plug the printer cable in I got a full on 120VAC shock as my finger was guiding the connector into the back of the computer. In my shocking moment I pulled quickly away from the energy, dragging the metal shield of the cable across the back of the computer. No breaker tripped! Potentially a shock hazard that had I been using two hands, one on the cable and the other on the computer - that current would have passed across my chest.

This is why you can't say "it Shouldn't" because it "MUST" matter. Modern electronics require proper polarity. If you need to be certain of your outlet - GET A TESTER! In my arsenal of test gear I have the plug in tester with the three lights. It also has a Ground Fault Circuit Interrupter TEST button. Press it and the GFCI should immediately cut the power to the outlet.

Don't discount your safety just because you don't know if the socket is properly wired. KNOW it's properly wired. It's not expensive or difficult to tell if an outlet is properly wired. Unless you encounter some fool who didn't know wires were reversed and didn't plug in a tester.

 

Followup to post #30: I really should have an electrician wire in a properly grounded ground source. For now the ground is disconnected and labeled "No ground". BUT: Polarity is now proper in all outlets.

 

It DOES matter .

As said earlier, the fuse must be on the LINE and go before the switch, among other safety concerns.

I'd agree IF we knew there was a fuse and the switch was single pole. He claims he cannot access the insides so it might not even have a fuse.

 

it might not

Would you base your safety and the safety of your family on that statement?

 

I understand you Tonyr completely.
My first job was electric installations, and I found out first hand (my hand that is) that there are talents who were wiring the neutral to the switch and the hot directly to the ligthbulb, so you have 220V above your head even if you turned off the switch.

My point was... according to electrical standards it MUST matter which is neutral or hot. Purely for the functioning of the device - probably not.

 

Would you base your safety and the safety of your family on that statement?

No, but then there are few things I would!

 

I understand you Tonyr completely.
My first job was electric installations, and I found out first hand (my hand that is) that there are talents who were wiring the neutral to the switch and the hot directly to the ligthbulb, so you have 220V above your head even if you turned off the switch.

My point was... according to electrical standards it MUST matter which is neutral or hot. Purely for the functioning of the device - probably not.

I'd open the unit up and replace the cable with color coded, better cable I think, resolve the matter and be done.

 

I'd open the unit up and replace the cable with color coded, better cable I think, resolve the matter and be done.

100% agree. Better solution than putting a "Fix-It" plug on the end of a cable when you're unsure what goes where. Even if you're 90% sure which is neutral and 100% sure which is ground. While you just might get away with it it's not worth the risk. Especially if this is in a rental unit. Someone gets a shock - gets mad - gets an attorney - gets rich just because of a stupid plug that accidentally got wired wrong?! Being the smart AND CROOKED kind of guy I might be - I would unplug the unit, change the wiring, make the ground poor, put it all back together then get a shock. Call the cops so they can then see there's a potential for injury, get documentation on it - then sue you. OK, that's not who I am. But - - - !

 

It's been four days since we last heard from the TS. Is this still a thing? Or have you resolved the problem to your satisfaction?

 

If nobody is going to be poking their hands inside the wiring of the window AC appliance while it is plugged in to a live source, AND if the green-wire safety connection is good from that AC unit's frame to a solid GROUND, then there does not exist a hazard, except in the minds of some folks.

 

If nobody is going to be poking their hands inside the wiring of the window AC appliance while it is plugged in to a live source, AND if the green-wire safety connection is good from that AC unit's frame to a solid GROUND, then there does not exist a hazard, except in the minds of some folks.

But this isn't a plugged in unit - it's a unit whose plug has been chopped off. The TS wants to replace the plug with a Fix-It 3 pronged 120VAC plug. The chances of wiring the plug wrong is very real. Swap the neutral and hot could lead to a potential shock IF the ground connection is not properly made.