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GX connectors (unofficially called "aviation") are used for a wide variety electrical applications, including supplying power to soldering irons and motors. Usually, the voltages are low, around 5V to 24V, but they are also used to supply much higher voltages, such as 90VDC. The design of the connectors, however, poses an electrical hazard.

The male pin connector (pictured right) is designed for installation at the source, such as the front panel of a soldering station, while the mating female connector (pictured left) is attached to the ends of the cable. This leaves the male end exposed leading to a short if something conductive happens to brush against its pins. Even worse, if fingers brush against them it can result in a shock. If genders were in the opposite configuration, the pins on the cable connector and the pin sockets on the panel connector, it would be safer since the pins are never exposed when live.

Female Connector, Left. Male Connector, Right.

Are GX connectors being misused for power applications, is this hazard a design oversight, or is there another reason I might be missing? Oddly enough, I've never seen the connectors available in opposite gender configuration.

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    \$\begingroup\$ If there were to be high voltage to become present on the pins of the panel-mount receptacle, it should be the case that those voltages only become developed once the plug is inserted and should be removed quickly if the plug is removed. An extra pin or two may be required for this. Perhaps the plugged device includes an inductance or capacitance that is fundamentally required for oscillation to occur, to develop the high voltage, and that without it the device's circuitry simply can't oscillate and won't develop the high voltage. \$\endgroup\$ Commented Nov 6, 2023 at 0:19
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    \$\begingroup\$ A quick search for "GX connector" yields lots of results with the opposite gender configuration. \$\endgroup\$
    – jcaron
    Commented Nov 6, 2023 at 11:35
  • \$\begingroup\$ The connectors pictured may be useful when the cable is supplying the power to the device. \$\endgroup\$ Commented Nov 6, 2023 at 14:01
  • \$\begingroup\$ @jcaron could you link a few from your quick search? I don't see any female bulkhead connectors on at least the first pages when I put 'GX connector' in Google image search. \$\endgroup\$
    – BrtH
    Commented Nov 7, 2023 at 2:36
  • \$\begingroup\$ @BrtH renhotecpro.com/product/… (not sure exactly which series your connectors are though). probots.co.in/… but they only have a limited number of types in that style. elecbee.com/… again not sure of the exact series you need. Adding "reverse" to the search helps a lot. \$\endgroup\$
    – jcaron
    Commented Nov 7, 2023 at 10:50

6 Answers 6

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The connectors themselves will be fine up to their rated voltage/current (subject to temperature or altitude derating). Using them for power isn't necessarily a "misuse" of the connector but having hazardous voltages exposed on touchable pins is just plain bad design.

The other consideration is whether the potential exists for another cable with a matching connector to be accidentally plugged into the system. We see this a lot with people trying to use e.g. RJ-45/8p8c, XLR, or DE-9 connectors to supply power or nonstandard data configurations. While understandable, as "proper" connectors can be expensive and hard to find, this is also frowned upon.

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  • \$\begingroup\$ RJ-45/8p8c is commonly used to supply power; see Power over Ethernet (PoE). In general, it can be safely used for 48V because pretty much every Ethernet device will withstand that, and non-Ethernet users of RJ-45 tend to adopt similar tolerances. \$\endgroup\$
    – MSalters
    Commented Nov 7, 2023 at 15:08
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    \$\begingroup\$ @MSalters: As is XLR, with 48V "phantom power" for mics being standard... Unfortunately, even Ethernet RJ-45 jacks seem to have no tolerance for PoE – I almost fried my new laptop with the wrong cable from Ubiquiti "passive 24V PoE", judging from the smell that lingered for a while. \$\endgroup\$
    – user1686
    Commented Nov 7, 2023 at 15:47
  • \$\begingroup\$ @MSalters yes I am aware of PoE. I am talking about people who want to use these connectors for nonstandard configurations. \$\endgroup\$
    – vir
    Commented Nov 7, 2023 at 17:18
  • \$\begingroup\$ PoE was invented when people realized you could safely add power to a standard Ethernet connection, so it was non-standard before that. The key point is that existing standard Ethernet equipment and hardware was already tolerant of these voltages. \$\endgroup\$
    – MSalters
    Commented Nov 8, 2023 at 11:18
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OP said

The male pin connector (pictured right) is designed for installation at the source, such as the front panel of a soldering station, while the mating female connector (pictured left) is attached to the ends of the cable

That may be true for the connectors pictured, but is not true in the general case.

and

If genders were in the opposite configuration, the pins on the cable connector and the pin sockets on the panel connector, it would be safer since the pins are never exposed when live.

Yes that's correct.

There's almost always an option for a pair of mating connectors as to which side will house pins and which will house the mating receptacle, particularly in MIL/AERO world. I can't this with 100% certainty (because I can't claim to have personally seen every connector type that exists ), but most connectors come with the option of having either the male (pin), or female (receptacle) on either the fixed part of the interface (where it uses a J nomenclature) or on the movable part of the connection (where is uses the P designation). Having this flexibility reduces the chance of shorting out power should male pins be used on the power source end.

And as to your "high voltage" comment, a cursory perusal of the Amphenol catalog gives a typical dielectric withstanding voltage of 1000 VDC, at sea level for their high density (non-power) connectors.

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  • \$\begingroup\$ There are connectors where you don't get that choice, though--a number of wire-to-board connectors have one polarity that you can only get as the PCB-mount part, and one that only comes as the wire-mount part. For anything that's sufficiently standardized, though, someone will probably make all possible configurations, even if the standard explicitly disallows them. \$\endgroup\$
    – Hearth
    Commented Nov 5, 2023 at 22:22
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    \$\begingroup\$ For a connector application where a choice of male/female is not available in the configuration you need, then chose another connector. \$\endgroup\$
    – SteveSh
    Commented Nov 5, 2023 at 22:30
  • \$\begingroup\$ The common DC barrel jack is close to a counterexample. You can get inline sockets, but panel mount plugs are vanishingly rare, unknown in many common sizes \$\endgroup\$
    – Chris H
    Commented Nov 6, 2023 at 9:44
  • \$\begingroup\$ The panel, or chassis mounted part of a connector pair - the less movable part of the pair - is generally referred to as a jack, not a plug. \$\endgroup\$
    – SteveSh
    Commented Nov 6, 2023 at 11:26
  • \$\begingroup\$ @SteveSh with hollow connectors, the male/female distinction can get rather vague, so plug/socket becomes more sensible. The use of "jack" in this sense is anyway one I have to translate a bit - it's more common in American English. But regardless of terminology, my point stands \$\endgroup\$
    – Chris H
    Commented Nov 6, 2023 at 11:43
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Any connector with touchable high voltages are unsafe. But that's not the fault of any connector, but how some designer decided to use it.

If the connector itself is rated for 500V and 10A then in theory you could use it for mains voltage, but it would not be wise to do so, it might not be approved for mains. It just means it can be used for an isolated data interface where there can be 500V between chassis and data wires, like Ethernet.

However, if you see an aviator connector on a cheap device, it is really not an expensive aviation rated connector, but simply a matching looking cheap clone with only rating for small voltages and currents. And cheap devices might have design problems anyway, there should never be any dangerous voltages present on touchable parts on a device.

So any connector and their cheap clones can be used for any purpose, even unsuitable and dangerous purposes.

For example it seems to be a craze to buy USB cables with these aviator connectors in the middle (for gaming purposes, to save USB connectors and wear out the aviator connector when swapping between gaming keyboards).

The problem is, USB connectors are specifically designed for hot-plugging and have a specific sequence that ground and supply wires mate first and when everything is settled then the data wires mate last. These aviator connectors do not guarantee that and you can damage your PC USB port or the keyboard with hot-plugging a connector not designed for hot-plugging USB.

And some cheap smoke machines use 3-pin XLR connectors for mains voltage.

The same applies with using these for high voltages. They may be suited for high voltages when mated, but obviously, you should not allow people to come in contact with exposed high voltage, because then you are doing something wrong. You as the user should also understand not to unplug these if they are used for high voltage, unless the system is turned off.

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This configuration was probably designed this way because the external thread offers protection to the male pins on the chassis side, whereas on the cable side the ring with internal thread doesn't offer this protection. If the male pins where on the side with the ring, they would not be protected and they could bend. So they choose to put the ring on the female connector.

It happens that the ring is on the cable because it's easier to screw it on. If the ring were on the chassis side, you would have to turn it counter-clock wise which is not intuitive, and hold and press the cable forward with the other hand. Here you can mate the cable with one hand without applying pressure on the cable. This construction is designed to avoid pressure on the cable.

In this sens, it makes the so called female like a male, and the male like a female.

It's of course not suitable for potentially hazardous voltages.

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  • \$\begingroup\$ Whether a connector is a plug or a receptacle and whether it uses pins or sockets are not necessarily related. The choice of pins vs sockets is typically based on which side has the potential to be "hot" in a demated configuration \$\endgroup\$
    – Tristan
    Commented Nov 7, 2023 at 15:38
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They're unsafe at any voltage unless you can track down their manufacturer and get an underwritten guarantee of their specification.

Do not trust random stuff bought via Amazon, eBay or Ali.

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The connector voltage ratings seem to vary from manufacturer to manufacturer (and they also vary with the number of pins in the connector- those with 5+ pins have a lower rating than those with fewer pins.

I don't anything less than 125VAC rating according to manufacturer's specs, with test voltages in the 1.5kV-2kV range for 60s (less for higher pin counts).

Similarly, the current rating is lower for higher pin count connectors, as you might expect, decreasing from 7A to 5A to 4A depending on number of pins.

Putting dangerous voltages on exposed pins is bad design, of course.

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