DC power plugs & jacks - suitable for use with AC power or no?

**Scoobysnacks** · 01-10-2017, 08:58 PM

Those with more AC electricity knowledge- please chime in on this one.

Do you see any reason why these style of common power connectors typically used for low voltage DC applications could not/would not be suitable for interconnects on a 120V AC situation where weather-proofing is NOT an issue?

Big picture: in true DIYC spirit, I want to design a way to have a compact, pluggable setup for 120V AC LED light strings into my own enclosure for an AC light controller. I don't like how all the SPT wire+vampire plugs hang out of the enclosures the way most people build them. They don't store very well with all that (crap) hanging out of them, so I found myself thinking there's gotta be a better way.

Using an intermediate cable with a female vampire socket to one of these DC plugs, I could then have a modular (and compact way) to plug AC lights into my controller box. Since LED lights pull very little current (~4.8W = 0.04A = 40mA) on average, I don't consider that to be an issue for these connectors.

Polarity should be irrelevant. Thoughts from those more experienced?

**iflights** · 01-10-2017, 09:31 PM

DIY Spirit also means doing things in a safe way. This is not a safe solution.

**ChiefKC** · 01-10-2017, 09:50 PM

Having spent 20 years working in the electrical field, this is not safe. I understand the desire for ease of setup and appearance, however safety must come fisrt and using those plugs is not safe at all.

8th Commandmant of Electrical Safety
Verily I say unto thee, never service high-voltage equipment alone, for electric cooking is a slothful process, and thou might sizzle in thy own fat for hours on end before thy Maker sees fit to end thy misery and drag thee into His fold.

**pjones** · 01-10-2017, 10:24 PM

The insulation may not be sufficient to isolate the higher voltage. Also it looks like your dangly bits could touch the pixies in the ends of those connectors pretty easy. That would be my first concern. If that is a standard stereo jack then you will short out the pins as it plugs in and out which makes the pixies mad.

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**algerdes** · 01-11-2017, 02:20 AM

The thing that scares me is if someone who doesn't know that is 120v AC plugs in a DC type appliance.
Short work of a trip to releasing the magic smoke - at minimum.

**Scoobysnacks** · 01-11-2017, 02:54 AM

These are standard 2.1mm ID x 5.5mm OD power jacks that everyone in this hobby should be familiar with, just like those found on your wifi routers, cable modems, network switches, and so on.

Although a number of you said you felt it wasn't safe, I was looking more for a factual substantiation for why or why not they would be acceptable for 120v AC usage. Many of us here are of the scientific/engineering mindset, so we do things based on fact/logic, not feelings.

The wire gauge that they can accommodate certainly isn't the issue. Heck, most big box store LEDs (and even incans) use flim-flam 22 or 24AWG wire. Is it the insulating properties between the 2 conductors that is the actual concern?

That's the only difference I see between these and AC wire plugs and mating receptacles. The conductors are much further apart.

**TED** · 01-11-2017, 04:27 AM

Originally Posted by Scoobysnacks

Big picture: in true DIYC spirit, I want to design a way to have a compact, pluggable setup for 120V AC LED light strings into my own enclosure for an AC light controller. I don't like how all the SPT wire+vampire plugs hang out of the enclosures the way most people build them. They don't store very well with all that (crap) hanging out of them, so I found myself thinking there's gotta be a better way.

You could install proper female AC connectors/receptacles into your enclosure. Then you could just plug in whatever you want (zip cord, lights, whatever) when it's in use and there would not be any dangling wires when it's not. I found several options by doing a quick search (for "flush AC female connector"). I'll post a couple below. (I'm sure you could find them cheaper than allelectronics or mouser.)

http://www.allelectronics.com/item/a...-outlet/1.html
http://www.mouser.com/ProductDetail/...Xj1Dqy4lU1Q%3d

If you want something that will work with a round hole like the connectors you posted the picture of, you could find something similar that is rated for AC. Here's another idea. You could rewire a power strip so that each socket is wired independently and attach it to the bottom of your enclosure (with the sockets pointed down to keep water out). There are many different options you could come up with so why not start with parts that are rated for AC?

TED

**pjones** · 01-11-2017, 04:46 AM

Originally Posted by Scoobysnacks

These are standard 2.1mm ID x 5.5mm OD power jacks that everyone in this hobby should be familiar with, just like those found on your wifi routers, cable modems, network switches, and so on.

Although a number of you said you felt it wasn't safe, I was looking more for a factual substantiation for why or why not they would be acceptable for 120v AC usage. Many of us here are of the scientific/engineering mindset, so we do things based on fact/logic, not feelings.

The wire gauge that they can accommodate certainly isn't the issue. Heck, most big box store LEDs (and even incans) use flim-flam 22 or 24AWG wire. Is it the insulating properties between the 2 conductors that is the actual concern?

That's the only difference I see between these and AC wire plugs and mating receptacles. The conductors are much further apart.

I should have looked closer at the picture, I saw the black body and made an assumption of a phono jack. I was trying to get a quick reply in during an oil change but the mechanic kept asking questions so didn't get to zoom in on this tiny screen.

It's the type and thickness of insulation that concerns me. As I'm sure you know, thickness of the wire determines the ampacity where as the insulation determine the wires voltage rating. Thicker insulation (or different insulation material) will provide better resistance to arking and allow for higher voltages.

That being said, I have not looked up the voltage specs for those connectors.

Polarity will make a difference only in the sense that it would be easier to touch the outside jacket when inserting and removing than it would be to touch the inner pin. The hot wire should always be the hardest to make contact with. Neutral is after all in essence just an insulated ground wire when we're talking about household AC power. It's the hot wire that bites.

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**Utimgr** · 01-11-2017, 01:39 PM

Two words...creepage and clearance, similar to when a PCB is laid out, and as a previous post said...the conductors are further apart. The dielectric breakdown of the plastics could allow voltage to actually pass thru the insulators, so you need to read the specs of the connectors carefully. In fact, many of these barrel jacks are only rated to a fairly low voltage so just thinking...its DC, isn't good enough. You need to make sure its rated for the voltages your using, and the current of course.

**todd1814** · 01-11-2017, 02:34 PM

Exposed conductors are always dangerous. That's why AC plugs have hidden conductors on the live side. All you have to do is touch the outside of these to receive a shock. You might consider yourself wise enough to make sure there's no power when handling the enclosure but it may expose a child, neighbor, spouse, pet, etc. Heat dissipation and arcing are also going to be a problem.

The solution you're looking for will undoubtedly cost more than having pig tails. You could always try something like this.