Getting shocked by g29 pedals, what do?

[2zqa]

Hello all,

It's been a while since I used the racedepartment website (or any real forum in general) but it's nice to be here again. I'm a casual g29/acc simracer with ambition to slowly get better over time. However when was racing last time I noticed I was getting a shock when I touched my radiator, and when I held my foot on a pedal and touched the radiator I believe I became part of a closed circuit and it hurt. Everything is fine without the pedals connected.

I think the cable is broken, considering the picture below, but could it perhaps be something else? Replacement cable is 36 euros, so if it could be anything else I'd prefer to check that first.

(Also since I'm quite a newbie to electricity but curious: what specifically happened/broke inside the cable that would cause this, assuming that's the problem? Maybe the ground wire broke in two or something, or touching another wire?)

 

[R8pilot]

Radiators are generally grounded, meaning actually connected to the earth, so that certainly could be one side of a short.

You don't really explain what that wire comes from or goes to, etc., except to imply that it's part of the pedals. However, almost all sim gear such as pedals operates on low voltage, i.e. 3.3 to 5V for most controls, which is generally too low to result in a shock. If that cable is a USB cable, or if it goes to a switch, it's unlikely to be carrying any more than 5V. It also doesn't seem to have a protruding bare wire anyway. If anything, it may be the absence of a proper ground (due to the cut cable) that is the problem.

Your wheelbase might use 12 to 48V (this info is probably on your base or its power supply), and could possibly result in a shock that could be felt (though not likely dangerous).

One thing to check right away: All of your electrical plugs that go into the wall should have 3 prongs, and they should all be in three-prong wall sockets. People sometimes use "cheater" devices that allows plugging a 3 prong plug into a 2 pronged socket. Don't do that without using the ground! If your sockets are only 2 prongs, then those "cheater" devices actually should be used - but only the ones with an extra tab on them. That tab is screwed into the screw on your wall socket, which is grounded. It's a way of connecting to ground without the plug having 3 prongs.

Another thing: "Ground loops." It's slightly technical, but these are currents that flow between two "grounds" that are not actually both at the same potential. To avoid them, plug all mains power into the same socket. You may need an extension with a box with several outlets. But all mains power should connect to one single point. Don't plug one thing into one socket and another somewhere else.

I recommend disconnecting all of your electronics from their power sources, inspecting everything, and redoing all connections in a systematic fashion, making sure everything is properly grounded, preferably to the same single point. (And obviously, if that cable needs to be used, then it needs to be repaired or replaced.)

 

[2zqa]

Radiators are generally grounded, meaning actually connected to the earth, so that certainly could be one side of a short.

You don't really explain what that wire comes from or goes to, etc., except to imply that it's part of the pedals. However, almost all sim gear such as pedals operates on low voltage, i.e. 3.3 to 5V for most controls, which is generally too low to result in a shock. If that cable is a USB cable, or if it goes to a switch, it's unlikely to be carrying any more than 5V. It also doesn't seem to have a protruding bare wire anyway. If anything, it may be the absence of a proper ground (due to the cut cable) that is the problem.

Your wheelbase might use 12 to 48V (this info is probably on your base or its power supply), and could possibly result in a shock that could be felt (though not likely dangerous).

One thing to check right away: All of your electrical plugs that go into the wall should have 3 prongs, and they should all be in three-prong wall sockets. People sometimes use "cheater" devices that allows plugging a 3 prong plug into a 2 pronged socket. Don't do that without using the ground! If your sockets are only 2 prongs, then those "cheater" devices actually should be used - but only the ones with an extra tab on them. That tab is screwed into the screw on your wall socket, which is grounded. It's a way of connecting to ground without the plug having 3 prongs.

Another thing: "Ground loops." It's slightly technical, but these are currents that flow between two "grounds" that are not actually both at the same potential. To avoid them, plug all mains power into the same socket. You may need an extension with a box with several outlets. But all mains power should connect to one single point. Don't plug one thing into one socket and another somewhere else.

I recommend disconnecting all of your electronics from their power sources, inspecting everything, and redoing all connections in a systematic fashion, making sure everything is properly grounded, preferably to the same single point. (And obviously, if that cable needs to be used, then it needs to be repaired or replaced.)

First of all thank you for taking the time for such a detailed response. To clear up the confusion:

> You don't really explain what that wire comes from or goes to, etc., except to imply that it's part of the pedals.

My bad, the connections are as follows:

Logitech g29 is connected by USB and has a power supply that is only two-prong (EU plug), so no grounding here. Unsure about power. However the issue only started recently so it shouldnt be the main issue I think.

There is a serial port for the pedals in the wheelbase. Picture (not mine): https://pcper.com/wp-content/uploads/2015/07/4646-dsc03148.jpg

Hope this explained it.

> I recommend disconnecting all of your electronics from their power sources

I disconnected the pedals from the base and this solved the issue, but I will try removing other devices to see if it helps. However I'm currently away from my rig for the following 2 weeks so it's going to be a while.

 

[GeekyDeaks]

My PSU only has the two connections, so I don't think it's likely to be a problem with a faulty earth.

Another thing: "Ground loops."

I suspect @R8pilot is correct and this is probably the cause. The G29 pedals have a ground connection to their frame, which will mean the pedal faces will be grounded. The wheel has in-built protection for a short and will reset, so if you haven't experienced it randomly re-calibrating, I don't the cable is likely to be an issue as it doesn't actually look too bad.

I second @R8pilot's advice about disconnecting everything and making sure the G29 power is plugged in as close as possible to the PC

 

[2zqa]

Thank you both for the replies. I might be able tot check this weekend but I will come back to this thread with results when I have them. (Rig is at my parents place..)

 

[Neilski]

Further to the advice above, I have a G27 and I have what I think is the same problem.
I first got bitten by it while clambering around under my desk to get at the back of my PC, and allowing my bare forearm to touch the pedal faces while my fingers were touching the metal PC chassis. OUCH!

It only happens when the wheel's USB cable is unplugged from the PC - as soon as I plug in the USB cable, it grounds the pedals and bingo, problem gone. (Desktop PC with an earthed cable to the mains.)

Basically, what's happening is that my wheel's PSU doesn't have a ground pin on the plug and although it's generating what's purportedly a floating DC supply at 24 V, sadly there's a wee bit of leakage from the AC side (for reasons I only partially understand) which is very happy to flow to ground, given any opportunity... e.g. through our flesh! Although the available current is very small (well under 1 mA [edit: actually I should say *probably* less than 1 mA but it could be a wee bit more]), the voltage it can reach without a load is pretty large and more than enough to give a significant tingle or even an unpleasant feeling like you've been stuck with a pin. (I've not measured the voltage from the supply on my G27, but I've seen voltages of a little over 100 V on another brand-new 12 V DC supply at my workplace, which I promptly discarded in favour of a grounded one! )

Note that the cable to your pedals doesn't need to be damaged to generate this issue (it's nominally only carrying 3.3 V anyway).
Since you are experiencing the problem even when driving, I guess your PC isn't grounded, so I'm gonna guess that it's a laptop. In this case, you may even find that the laptop itself is part of the problem... The second piece of kit in my home that exhibited this problem was my wife's metal-chassis laptop - which gave an odd sensation when you ran your finger over the surface while it was plugged into the charger... almost like a buzzing. Lots of laptops these days have the same issue, apparently.

On my G27, unplugging the pedals from the wheel doesn't totally cure the issue - the metal spokes of the wheel itself are also on the same internal ground and so have the same problem (I just don't tend to touch them with the more sensitive skin on my arms while also touching an earth, hehe). (NB: the shifters are NOT connected to ground on my wheel - just the three spokes.)

I have contemplated earthing the pedals, but not yet done it. My "solution" for now is to just unplug the wheel PSU when connecting cables at the back of my PC because I normally leave the USB cable unplugged (since I use my desk for other things and the wheel will otherwise go into orbit when I boot the PC!).

 

[2zqa]

Well I just tested the wheel with my college laptop and my suspicions were indeed incorrect (whew!). The wheel is fine! I tested it with GT Legends (poor laptop) and everything works without shock. Now it's the question what the culprit was instead.

 

[Neilski]

tested the wheel with my college laptop

Is this not the machine you were using at first?
(And does it have an earthed PSU?)

 

[2zqa]

Is this not the machine you were using at first?
(And does it have an earthed PSU?)

Oh, I totally missed your reply! Now you mention it, my PSU has a grounded connector, however it's plugged in a wall socket that isn't. For my laptop, I just simply didn't charge it while testing. I suppose using another outlet would fix it, but sadly there are none in this room. I also still find it weird that it worked fine for so long. Luckily I'm moving my rig to my own place in a few weeks.

Lots of laptops these days have the same issue, apparently.

Also mine when it's plugged in the charger, just like my previous laptop. Mildly infuriating actually..

12 V DC supply at my workplace, which I promptly discarded in favour of a grounded one! )

Way better! If mine ever breaks or something I should definitely keep this in mind as well.

My "solution" for now is to just unplug the wheel PSU when connecting cables at the back of my PC because I normally leave the USB cable unplugged (since I use my desk for other things and the wheel will otherwise go into orbit when I boot the PC!).

Smart! You could probably also get an extension cord with switch, bit more convenient.


As mentioned my PC/wheel is still at my parents place and I didn't have a lot of time today so I'll have to come back next week to see if I can perhaps find another solution, idk maybe some other device or extension cord is causing this (if that's even possible). Luckily I'm planning on moving my setup to my new dorm in a few weeks time.

 

[Neilski]

Way better! If mine ever breaks or something I should definitely keep this in mind as well.

If you do want to do this, don't forget that the wheel uses a 24 V supply - or at least the G27 does