Getting electric shocks from Logitech G29 + wheelstand

[Cantatablau]

I'm using a Logitech G29 with a GT Omega wheel stand. When I use it with my PlayStation, it doesn't give me any problems, since I just plonk it in front of the couch, turn it on, and game away. However, in the last few days I've started to use it with a PC, so sometimes I need to lean over it to use the keyboard or mouse. I've noticed that after 5-ish seconds leaning on the platform where the wheel is mounted, I get a painful pricking sensation in my forearms and "butterflies" in my stomach/chest. This effect is not replicated when the wheel is unplugged, so it's clearly not just static electricity from my body hair or anything like that.

I have dismounted the wheel from the stand and have inspected the power brick, cables and connections. The power brick and cables seem fine, but the barrel plug is wiggling around quite a lot when it is inserted. Is this likely to be a fault with the wheel? Could this be causing the shocks? Should I be worried about my health? I'm not sure if it's important, I live in Mexico and the power supply is 120V and we use North American plugs. The power supply that came with the wheel is not grounded.

Should I:
a) buy a grounded power supply?
b) put some kind of insulating material on the wheel mounting platform (like a sheet of rubber)?
c) wear long sleeves when I use it?
d) return the G29 for a replacement (it's still within the Amazon return period)?
e) something else?

Any advice would be very much appreciated.

 

[Neilski]

I think you're experiencing the same thing as is described here: https://www.racedepartment.com/threads/getting-shocked-by-g29-pedals-what-do.209246/
My feeling is that it's the same ol' mains leakage issue that many laptop power supplies exhibit, linked to capacitors whose role is to reduce emissions (EMI), or at least that's my understanding. I think it's really naff that this is regarded by manufacturers as being acceptable, but it seems to be compliant with the regulations so...

I have a similar issue with my G27, but only when I haven't got the USB cable plugged into my PC - once it's plugged in, the problems vanish because the PC is earthed through its power supply, and thus the wheel is earthed through the USB cable.

Your PC sounds like it isn't earthed? (Laptops are often not earthed through their power supplies, but I'd be pretty surprised if a desktop machine didn't have a solid earth, since most of them have shedloads of exposed metal.)

Earthing the PC (or anything in the circuit, including the pedals) might be the simplest option. Finding a new wheel PSU with an earth might be the least easy option but worth exploring.

 

[Cantatablau]

I think you're experiencing the same thing as is described here: https://www.racedepartment.com/threads/getting-shocked-by-g29-pedals-what-do.209246/
My feeling is that it's the same ol' mains leakage issue that many laptop power supplies exhibit, linked to capacitors whose role is to reduce emissions (EMI), or at least that's my understanding. I think it's really naff that this is regarded by manufacturers as being acceptable, but it seems to be compliant with the regulations so...

I have a similar issue with my G27, but only when I haven't got the USB cable plugged into my PC - once it's plugged in, the problems vanish because the PC is earthed through its power supply, and thus the wheel is earthed through the USB cable.

Your PC sounds like it isn't earthed? (Laptops are often not earthed through their power supplies, but I'd be pretty surprised if a desktop machine didn't have a solid earth, since most of them have shedloads of exposed metal.)

Earthing the PC (or anything in the circuit, including the pedals) might be the simplest option. Finding a new wheel PSU with an earth might be the least easy option but worth exploring.

Thanks for the reply. The "PC" in question is actually a Bootcamped iMac, and I'm pretty sure it's earthed (it has a 3-prong plug and is plugged into a Koblenz surge protector, which also uses a 3-prong plug). I only have basic knowledge about how electricity works, but could that leakage you mention mean that some of the electricity from the wheel/pedals is somehow "leaking" into my wheel stand and zapping me when I touch it?

 

[Neilski]

The "PC" in question is actually a Bootcamped iMac, and I'm pretty sure it's earthed (it has a 3-prong plug and is plugged into a Koblenz surge protector, which also uses a 3-prong plug).

OK, so then I'm puzzled. Is the iMac powered from a power brick with a DC output (in which case it may be floating rather than earthed), or an internal AC power supply fed directly by the mains?
Perhaps the earthing is faulty - if you have a multimeter then you could do some checks on this.

I only have basic knowledge about how electricity works, but could that leakage you mention mean that some of the electricity from the wheel/pedals is somehow "leaking" into my wheel stand and zapping me when I touch it?

Yes. If the wheel isn't earthed, then you should get the same pricking sensation effect if you lay (say) your forearm against a pedal or the exposed metalwork on the wheel itself (spokes, paddles?). And since the wheel is presumably bolted to the stand using the tapped holes on the underside, I'm gonna say that any leakage reaching the wheel circuitry will therefore be passed on directly to the stand.
You also have the option to just earth the stand itself, which will earth everything else linked to it (wheel, pedals, PC). You don't want ground loops, since they can cause issues, but the fact that you're getting shocks seems to be proving that nothing is earthed at present. (OR I could be just plain wrong... I'm not a qualified electrician.)

 

[trichens]

The mains voltage for the Logitech wheel only goes as far as the PSU brick, after that it's going to be low voltage - only 24V I believe.

What electrical cables are connected to the Omega wheel stand?

TBH I'd suspect your PC is the problem.
It could be that your earth from that that is connected to the USB earth is actually live? If the G29 wheelbase has an earth that is linked to the USB earth and one or more of the G29 fixings then that could make the frame live?

How is the wheelbase fixed to the wheel stand?
If you are using screws into the case try using the clamp mounts instead so there is no metel to metal connection.

 

[Cantatablau]

The mains voltage for the Logitech wheel only goes as far as the PSU brick, after that it's going to be low voltage - only 24V I believe.

Ok, so not high enough to be worried about? If I buy a third-party earthed PSU like this one, could it solve the problem?

What electrical cables are connected to the Omega wheel stand?

Basically I've got the PSU connected to the G29 wheel base, the pedals also connected to the wheel base via VGA, and the wheel base connected to the gaming device (PS3 or iMac) via USB. Just out-of-the-box G29 stuff. I have the pedal cable and the PSU cable cable-tied to the stand for cable management, but I checked all of that and found no problems.

TBH I'd suspect your PC is the problem.
It could be that your earth from that that is connected to the USB earth is actually live? If the G29 wheelbas has an earth that is linked to the USB earth and one or more of the G29 fixings then that could make the frame live?

I've just tested with my PS3 and the stand is not zapping me, so it seems like this could be the answer and the iMac is the problem. Possibly faulty earth?

Yes. If the wheel isn't earthed, then you should get the same pricking sensation effect if you lay (say) your forearm against a pedal or the exposed metalwork on the wheel itself (spokes, paddles?). And since the wheel is presumably bolted to the stand using the tapped holes on the underside, I'm gonna say that any leakage reaching the wheel circuitry will therefore be passed on directly to the stand.

Weirdly, it's only coming from one very specific part of the stand, where the wheel-mounting platform connects to the upright: here. The wheel rim and the pedals don't cause me any shocks, despite the fact that I play barefoot.

 

[Neilski]

Ok, so not high enough to be worried about? If I buy a third-party earthed PSU like this one, could it solve the problem?

That PSU seems to be suitable for the wheel itself, but even though it has a 3-pin mains cable, I can't see a way to be certain that the DC cable will actually have the 0 V line tied to earth (but there's a good chance of that).

NB: the underlying issue isn't the 24 V, it's the spikes of much higher voltage (I've seen over 100 V on other PSUs) that come through to the DC output due to the filtering capacitors in the PSU. The leakage current in a properly-functioning and safe supply is strictly limited to prevent it causing any real harm, but that doesn't stop it feeling quite seriously unpleasant if it touches the wrong part of your body... (Especially if your body is earthed by another path.)

Weirdly, it's only coming from one very specific part of the stand, where the wheel-mounting platform connects to the upright: here. The wheel rim and the pedals don't cause me any shocks, despite the fact that I play barefoot.

Yeah that bit you show in the pictures looks like a nice bit of bare metal, so a good place to feel the shocks.
I don't own a G29 but when I look at pictures of the wheel spokes, they look like they may be coated in something and that might explain the lack of issues there.
If you touch the delicate skin of your inner forearm to the bare metal of any of the pedals though, you should feel that same nasty tingle. If you don't then I'm at a loss to understand... (Edit: my feet don't feel the shocks either, so I guess that feet are a bit less delicate.)

If I understood your first post correctly, you've already essentially demonstrated that the problem isn't with the iMac, because it goes away when you simply unplug the wheel, right?
Just to put this part beyond doubt though: if it's coming from the wheel's PSU, it will go away (i.e. not give you a shock from the wheel stand) when you unplug the DC power barrel plug from the wheel, OR when you remove the wheel PSU's mains feed with a switch or by simply pulling out the plug.

 

[Cantatablau]

If I understood your first post correctly, you've already essentially demonstrated that the problem isn't with the iMac, because it goes away when you simply unplug the wheel, right?
Just to put this part beyond doubt though: if it's coming from the wheel's PSU, it will go away (i.e. not give you a shock from the wheel stand) when you unplug the DC power barrel plug from the wheel, OR when you remove the wheel PSU's mains feed with a switch or by simply pulling out the plug.

In my original test, I had the wheel unplugged from everything (mains and iMac) to test if the zap wasn't coming from my body's own static electricity.

However, I've just retested the wheel on the iMac, and I am now unable to reproduce the pricking effect. When I unmounted the wheel from the stand to inspect everything, I noticed that I had pulled the DC cable pretty tight through the mounting channels molded into the bottom of the G29 wheel base. Now that I've remounted everything, I didn't run the DC cable quite so tight as I had done the last time (ie the barrel connector is now not flexing as much as before), so I'm inclined to believe that's what may have been causing the leakage. I'll play for a while tomorrow and see if the problem is solved.

 

[trichens]

I'd be interested to know exactly how any electricity is getting to the wheel stand frame TBH. If you are completing the circuit to earth by touching the frame then where's the supply coming from to make the frame "live"?
If it's an issue with the Logitech PSU then it would have to be coming via the wheelbase presumably through the fixing screws.

I've had my G29 in bits to swap the steering wheel and there's no metal to metal contact between the wheel itself and the wheelbase so you shouldn't have an issue with the whel spokes.

 

[Neilski]

However, I've just retested the wheel on the iMac, and I am now unable to reproduce the pricking effect. When I unmounted the wheel from the stand to inspect everything, I noticed that I had pulled the DC cable pretty tight through the mounting channels molded into the bottom of the G29 wheel base. Now that I've remounted everything, I didn't run the DC cable quite so tight as I had done the last time (ie the barrel connector is now not flexing as much as before), so I'm inclined to believe that's what may have been causing the leakage. I'll play for a while tomorrow and see if the problem is solved.

Ah, it's always a pain when you can't reproduce a problem, but of course the upside is that your problem may be gone
Honestly though, I see zero chance that the routing of the DC cable has been playing a role.
If your issue was truly like mine, a "sure fire" way of reproducing it ought to be to have the wheel disconnected from the PC and then power it up and let some delicate skin touch the metal of a pedal face.

I'd be interested to know exactly how any electricity is getting to the wheel stand frame TBH. If you are completing the circuit to earth by touching the frame then where's the supply coming from to make the frame "live"?
If it's an issue with the Logitech PSU then it would have to be coming via the wheelbase presumably through the fixing screws.

I've had my G29 in bits to swap the steering wheel and there's no metal to metal contact between the wheel itself and the wheelbase so you shouldn't have an issue with the whel spokes.

Aha, so either the G29 is different from the G27 in this respect, or I've simply been mixed up about having managed to zap my arm on a wheel spoke. (The routine problem for me is getting zapped on a pedal while crawling under my desk to rearrange stuff at the back of the PC.)
For sure, my assumption is that the tapped holes in the wheelbase are electrically connected to the 0 V feed from the wheel PSU and the pedal faces - that would therefore pass the spikes on to the wheel stand. (My G27 definitely has the pedal faces linked to the 0 V line but I am not certain I ever checked the tapped holes.)

 

[trichens]

The G29 pedals are most definitely electrically connected to the baseplate chassis.
I stripped mine down so I could have them top mounted - hanging down with the pivot at the top. All the potentiometers have wires that connect them to their brackets - these would have to be a common connection so that would be 0V/Ground/Earth.

Without checking I believe that I recall that the fixings for the pedal base were screwing into these metal brackets so this would make a connection to the wheel stand if the pedals are fixed with screws.
Are you pedals fixed to the wheel stand?
Could that be what links the wheel stand to some electrical power?

There are screws that fix the pedal faces through plastic spacers into the pedal arm so it's possible that these faces could also be linked to the same 0V of the wheelbase and I'd guess to the PC chassis through the USB connection? The screw heads will probably be connected to 0V anyway so if you touch a screw head with your foot that would complete a circuit?

What surface is the wheel stand on?
Does it have rubber feet to insulate it?
Are you in contact with the floor somehow when you get the tingling feeling, ?

 

[Neilski]

Without checking I believe that I recall that the fixings for the pedal base were screwing into these metal brackets so this would make a connection to the wheel stand if the pedals are fixed with screws.
Are you pedals fixed to the wheel stand?
Could that be what links the wheel stand to some electrical power?

Ah, good point - even if the wheelbase tapped holes aren't connected to the 0 V line then yes I also recall that the tapped holes under my G27 pedals go straight into the metalwork of the pedals, and I'm very certain that this is connected to the 0 V line (as are the pedal faces).

There are screws that fix the pedal faces through plastic spacers into the pedal arm so it's possible that these faces could also be linked to the same 0V of the wheelbase and I'd guess to the PC chassis through the USB connection? The screw heads will probably be connected to 0V anyway so if you touch a screw head with your foot that would complete a circuit?

My interpretation of what happens with my G27: spikes on the DC cable (probably ballpark 100 V but short duration and with limited energy/current behind them) reach the metal structure of the pedals. (The spikes are probably common-mode on both the 24 V and the 0 V line from the PSU, but I've not checked.)
These voltage spikes are capable of driving enough current into your body for you to feel it, purely by dint of the body's capacitance to earth, without you even needing to touch an earth. (The effect is more noticeable when I do touch an earth though.)
Edit: my assumption that the leakage is in the form of spikes could easily be wrong - I may need to borrow an oscilloscope so I can see what the waveform looks like...

 

[Neilski]

OK, so having had a fuzzy/incomplete/broken understanding of the details of what was causing my shocks for all these years, this thread finally pushed me to read more and try to properly understand it. Thanks for that @Cantatablau

In short: the capacitors I mentioned are able to supress the spikes of electromagnetic emission that would otherwise come from a switched-mode power supply (like most power bricks for the last few decades), but the compromise is that they generally do this by directly linking the incoming mains cables to the DC output with their (tiny) capacitance.
Hence, if you use a high-impedance voltmeter to measure the voltage on exposed metalwork fed by such a power supply, you're likely to find a high voltage (this depends on the capacitor network but it's likely to be half the line voltage).

I just used my multimeter (10 M Ohm input impedance) on my G27 (pedals are disconnected at present) and checked the voltage to ground with the power supply hooked up and the USB cable disconnected.
On the paddles, I got only around 5-6 V (AC, 50 Hz). On the tapped holes under the wheelbase it was even lower, at around 3-4 V. But on the spokes of the wheel I got almost exactly 120 V (!).
In hindsight, this makes perfect sense, because I'm in the UK with a 240 V mains voltage. I also now suspect that if I were to hook up an oscilloscope I'd see a reasonably clean sine wave, since the entire job of the capacitors is to kill the spikes from the switching circuit (by overwhelming the stray capacitance in the windings of the isolation transformer). Btw, when I measure the current available from the spokes to earth, it comes out at 0.1 mA, which appears to be in the range where some body parts can feel it and others can't.

So, assuming the G29 and G27 are electrically similar or even identical (other than the 3.3 V vs 5 V for the internal electronics), this confirms @trichens suspicion that the wheelbase's tapped holes won't be the cause of your problems, and instead it's gonna be the tapped holes in the pedals that are linking your stand to the leakage voltage.
Btw, the 120 V I see on the wheel spokes drops to under 20 V if I firmly touch my nearest earth point (radiator) with one hand and the spokes with the other... nicely demonstrating that the impedance of my body is dramatically lower than the multimeter

Consequences of this: I'm guessing you will probably have 60 V AC on your wheel stand (given your 120 V mains supply), and that this is probably coupled via the pedals. It may be pretty easy to either earth your stand or isolate the pedals from the stand...

 

[trichens]

Maybe try nylon M6 screws/bolts to fit it down?
Or you might find that some tape under your current bolt heads might work?

The only image that I can see of the Omega pedal plate shows slots so have the fixing bolts scratched the paint off this to expose bare metal?

 

[Atak_Kat]

Hello. I had an issue several years ago with my T300 when connected to my PS4. I did a lot of trouble shooting, and in the end I'm convinced the current was coming from the PS4 USB port somehow. NOT the power supply. When connecting to a PC, or other device, everything was fine. But only when I connected the PS4 would this happen.
I was using an alcantara seat at the time, and I believe this made it somehow worse. When I would put a covering over the seat, the issue would go away.

 

[Cantatablau]

Thanks a lot for your help and advice, guys.

So I played again today and felt the shocks again, a little stronger than before, but only from the mounting point that I showed yesterday in the photo, not from the pedals, wheel rim or paddles. I was also getting very light shocks from the iMac's aluminium chassis. My girlfriend came home and didn't feel any shocks at all. She was wearing platform heels and I was barefoot, so I guess I was earthing and she wasn't. Would playing with shoes solves the problem? The reason I play barefoot is that my feet are so big (size 13.5) that it's almost impossible for me to use the brake pedal without clipping the clutch unless I'm barefoot (or socks only).

Are you pedals fixed to the wheel stand?
What surface is the wheel stand on?
Does it have rubber feet to insulate it?
Are you in contact with the floor somehow when you get the tingling feeling, ?

The pedals are fixed by metal bolts, and the stand is placed on a tiled floor, with screw-in plastic feet. Here is a photo of the bottom of the wheel stand. And here is a photo of the overall setup. Do you think nylon screws will fix this?

Consequences of this: I'm guessing you will probably have 60 V AC on your wheel stand (given your 120 V mains supply), and that this is probably coupled via the pedals. It may be pretty easy to either earth your stand or isolate the pedals from the stand...

Is this dangerous? My understanding is that the amperage is what matters when it comes to electrocution, not voltage. Is this correct?

 

[Cantatablau]

Once again I've tested the wheel and stand with my PlayStation, but barefoot this time, and I can confirm that it is not giving me any shocks, so the problem must be either from the iMac or the tiled floor. When I play on the PlayStation, both my feet and the wheel stand are on a rug, and the floor is paved with a linoleum covering. Pic.

What would be the best course of action?

1. Buy an earthed PSU
2. Nylon bolts for the pedal plate
3. Earth the wheel stand (I don't really have the expertise to do this but I'm sure I could figure it out)
4. Use shoes
5. Cover the mounting point with an insulating material
6. Something else?

 

[Neilski]

So I played again today and felt the shocks again, a little stronger than before, but only from the mounting point that I showed yesterday in the photo, not from the pedals, wheel rim or paddles. I was also getting very light shocks from the iMac's aluminium chassis. My girlfriend came home and didn't feel any shocks at all. She was wearing platform heels and I was barefoot, so I guess I was earthing and she wasn't. Would playing with shoes solves the problem? The reason I play barefoot is that my feet are so big (size 13.5) that it's almost impossible for me to use the brake pedal without clipping the clutch unless I'm barefoot (or socks only).

I'm trying to make sense of this. It depends on where your feet were positioned when you were getting the shocks. If they were on the pedals, then I'm entirely at a loss to understand it, because your body would already have been connected (via your feet) to the 0 V line of the wheel system and so your arm shouldn't have got any kind of a shock from touching the screws on the stand. If however they were on the floor, then you'll probably have been slightly better earthed than your girlfriend who had heels on, making it more likely for you to feel the shock than her... (But see recommendation below.) If you wear shoes yourself then you will be slightly less well earthed; that may not be enough to prevent you getting any shocks at all, but heck, why not try it?

The pedals are fixed by metal bolts, and the stand is placed on a tiled floor, with screw-in plastic feet. Here is a photo of the bottom of the wheel stand. And here is a photo of the overall setup. Do you think nylon screws will fix this?

Nylon screws might isolate the pedals from the stand (and thus might cure the issue) but would they be mechanically strong enough to hold the pedals in place? I'm not sure.

Is this dangerous? My understanding is that the amperage is what matters when it comes to electrocution, not voltage. Is this correct?

The level of leakage current I'm seeing on my G27 power supply is unequivocally not dangerous (0.1 mA) and yes the danger to humans is basically about current rather than voltage (but we're resistive enough that low voltages like the 24 V DC on the wheel simply can't push enough current to harm us). The net effect of the tiny capacitor is akin to holding one end of a high-value resistor (say a couple of million Ohms) and touching a live mains wire with the other end. NB: I do NOT recommend trying that

Once again I've tested the wheel and stand with my PlayStation, but barefoot this time, and I can confirm that it is not giving me any shocks, so the problem must be either from the iMac or the tiled floor. When I play on the PlayStation, both my feet and the wheel stand are on a rug, and the floor is paved with a linoleum covering. Pic.

What would be the best course of action?

1. Buy an earthed PSU
2. Nylon bolts for the pedal plate
3. Earth the wheel stand (I don't really have the expertise to do this but I'm sure I could figure it out)
4. Use shoes
5. Cover the mounting point with an insulating material
6. Something else?

Honestly, the very first thing I'd recommend you do is to put beyond doubt which bit of kit is the source of the shocks - the PC or the wheel (or something else ). Just so we're sure what issue we're solving...
The scheme I'd propose would be to set it all up, confirm you're getting the shocks, and then just switch off or unplug the Logitech power brick. If the shocks go away, I think you can safely blame the wheel. If they don't go away, then I'd unplug the USB lead to the PC, with the Logitech brick powered up again. If they go away now, it's the iMac PSU. If they still don't go away, then the sanity check is to verify that they go away with both the USB lead unplugged and the Logitech brick powered off; if they finally go away then, the conclusion is that BOTH the Logitech and iMac supplies are contributing to the leakage (quite feasible, now that I consider it, and I guess that with two power supplies providing leakage, the maximum current will basically double, though the voltage will be unaffected). If the sanity check fails (i.e. the shocks still don't go away) then it would seem that neither supply is the source (Btw, an alternative to unplugging the USB lead would be to unplug the power supply for the iMac.)

I must confess though that the solutions are probably independent of the source. Earthing any part of the whole shebang (= wheel, PC, stand) should prevent the shocks from any part of the system, unless the iMac is somehow not connecting its 0 V line to the USB cable (this seems very unlikely). If the vendor can confirm that that earthed PSU links the earth to the 0 V line of the DC cable then that is probably a nice way to tackle it. (It would be stupid to sell an "earthed" PSU that doesn't do this, but stupid stuff happens.)
Insulating the mounting point (if you can really prevent the screws making an electrical contact with the stand) could also do a decent job - it would stop you getting a buzz from the stand, but not from the iMac chassis, so it might still be a good enough solution. You could even just put some insulation (e.g. tape?) over the screws on the stand which have been delivering the shocks (again, no shocks from that bit of the stand but potential mild shocks from iMac).
(Damn, sorry for yet another essay... :-S)

 

[GeekyDeaks]

Wild ass idea, but do you have a spare bit of wire long enough to reach from the pedal mounting bolts at the bottom to the wheel base mounts at the top via the frame (to make it neat). If so, just try stripping the ends and crimping each one with the mounting bolt to give a decent connection between the two bits of kit

 

[blekenbleu]

I get a painful pricking sensation

Seriously, if you value life, at least borrow a Voltmeter
and sort out the issues instead of guessing and hoping
that, because you are still alive, there is no danger.