Calling all old fogies: Is a two prong cord that dangerous?

[66Strat]

Anyway, if you are sure your guitar and your amp are grounded properly using your guitarstrings to touch anything you might get zapped from first should flip the fuse and prevent you from geting zapped.

Fuses are there to protect electrical equipment from damage, not people. By the time the fuse flips, potentially lethal current will already have passed through your body.

except for it would flow through the guitar strings and ground. Ok this only works if the fuse blows before the guitar grounding desintegrates.

Where do you think the guitar is grounded?

[shaun]

Thanks all - this was a great read and a timely reminder of safety issues. I got zapped on the lip once - probably my own fault for taping the mic to a metal pole. The stupidity of youth - it's a wonder I'm still breathing.

I don't know if this is the right place to ask the question, but I'm attempting to restore a hot chassis portable motorola radio. It has 2 bumblebees that I believe are acting as protective caps (can't find a model #, let alone a schematic). I'll probably replace the BBs with X2 caps, or perhaps an X and a Y. I need to have a closer look to figure a few things out.

The client wants an "old fashioned looking two prong cord" for the vintage effect - the old one fell to pieces. Using a 2 prong seems dangerous as hell to me, but I'm not sure that a 3 prong can be used with a hot chassis - is it as simple as connecting the neutral plus the ground to the chassis?
Thank you, as always.

UPDATE: Just found some good info on youtube and antique radio restoration sites. I grow less ignorant by the minute:).

[thetragichero]

also keep in mind that unlike guitar amps where the end user has easy access to half of the power cable via the input jack, which is connected to the bridge, strings, etc
this is why AA5 radios encased in bakelite were not nearly as dangerous as widowmaker guitar amps
that being said, it's 2021 and everything should have a 3 prong plug and chassis safety ground in my incredibly biased opinion

[Williamblake]

Anyway, if you are sure your guitar and your amp are grounded properly using your guitarstrings to touch anything you might get zapped from first should flip the fuse and prevent you from geting zapped.

Fuses are there to protect electrical equipment from damage, not people. By the time the fuse flips, potentially lethal current will already have passed through your body.

except for it would flow through the guitar strings and ground. Ok this only works if the fuse blows before the guitar grounding desintegrates.

Where do you think the guitar is grounded?

I guess you already know a Faraday cage so i wonder what your question refers to.

[shaun]

that being said, it's 2021 and everything should have a 3 prong plug and chassis safety ground in my incredibly biased opinion

I agree. I haven't found an answer to my original question, which is this: is it possible to convert a hot chassis using a 3pin power plug and cord? And if so, would the plug's round ground pin be connected to the chassis? I guess it seems obvious it would, and share the chassis with the neutral. But I wonder whether the neutral would would then need to be floated somehow?

[pdf64]

that being said, it's 2021 and everything should have a 3 prong plug and chassis safety ground in my incredibly biased opinion

I agree. I haven't found an answer to my original question, which is this: is it possible to convert a hot chassis using a 3pin power plug and cord? And if so, would the plug's round ground pin be connected to the chassis? I guess it seems obvious it would, and share the chassis with the neutral. But I wonder whether the neutral would would then need to be floated somehow?

No, that would be a breach of regs and will trip a safety breaker if the installation is wired to current standards. Rather you need a 1:1 isolation transformer to float the chassis from mains.

[shaun]

Aha. Thanks pdf64. Very good info for when I ever do another radio restore. This is a tiny bakelite radio with an AC line in as well as a battery pack - no room for anything else. So I guess it'll stay a 2 pin plug, albeit the modern version.

[66Strat]

Anyway, if you are sure your guitar and your amp are grounded properly using your guitarstrings to touch anything you might get zapped from first should flip the fuse and prevent you from geting zapped.

Fuses are there to protect electrical equipment from damage, not people. By the time the fuse flips, potentially lethal current will already have passed through your body.

except for it would flow through the guitar strings and ground. Ok this only works if the fuse blows before the guitar grounding desintegrates.

Where do you think the guitar is grounded?

I guess you already know a Faraday cage so i wonder what your question refers to.

My question is in regards to the highlighted text. What ground are you talking about? And when did the subject drift to faraday cages? I thought that we were discussing two prong wiring vs the need for dedicated earth ground (three prong wiring).

[EL34]

But truly, for those who remember using regularly a two prong cord, has anyone known anyone getting electrocuted using a two pronger? I haven't. Maybe I'm the lucky one. But I played a truck load back then. (still do!)

I remember getting shocks touching Fender amps on the chassis straps
I also remember lots of people getting shocks when they touched microphones

[Williamblake]

Much US 1950s residential wiring was plastic cable, no conduit.

This can be legal and safe IF a GFI is first in the run; then 3-hole outlets may be installed.

This does little or nothing for guitar buzz, of course.

> where to connect safety/earth to. Answer being not to any wire from the power company

AFAIK, you *always*, all places, connect Safety Earth to a power company wire. The connection may be indirect in some systems. But if truly not connected then "minor" company faults can blow out your walls.

I wrote that where i live you dont connect the neutral to earth at the breaker board and this was from memory and i am not sure about this any more. I remember having a hard time when figuiring out how to do the house wiring and i am having the same experience once again trying to find out what is right. In a fail state you would want the mains fuse to blow so you would have the neutral connected to safety/earth at the breaker board but i cant find this information again. To whom it may concern i dont feel bad about beeing a dumbass, it is all about getting this straight.

[sluckey]

Go buy a copy of the NEC. It will tell you exactly how the neutral shall be bonded to earth ground in the main entrance box. Please note there may be additional restrictions and rules imposed by local government.

But NEC has nothing to do with the wiring inside your amp. NEC rules stop at the convenience outlet.

Oops! Just realized you are in Germany. Never mind.

[PRR]

Read the NEC (or local equivalent). Or hire an Electrician. I'm not going to get involved in home wiring on-line.

If you are in Germany; unlicensed electric work is ILLEGAL, I believe. (Even telephone needs a degree.)

[Williamblake]

The difference for germany may be that you have your earth/safety which you have connected to your heating and plumbing and maybe bath tub to the neutral at one point only but little difference may this make. The faraday cage entering here is you would want your chassis to short things and flip the fuse before youself short things. So you could be a happy camper with to prong but why would you push your luck?

[pdf64]

Please can posts of a speculative nature, eg how earthing and phase arrangements may be, just stop?
Of course queries and good, solid info in response is the point of tech forums.
But mains electricity can easily kill, especially if the differing arrangements, regs and codes of different regions get all mushed up in the heads of people that don’t have a specific competence in the topic.
And once folks get an idea in their head it can be hard to shift it, no matter how wrong / dangerous it is.

[PRR]

> connected to your heating and plumbing and maybe bath tub to the neutral

Does Germany use TT, IT, TN-S, TN-C, TN-C-S, PME, MEN, or other earthing system?

[Williamblake]

> connected to your heating and plumbing and maybe bath tub to the neutral

Does Germany use TT, IT, TN-S, TN-C, TN-C-S, PME, MEN, or other earthing system?

As i already said i hired an electrician to install the breaker board and did this for a reason. What i do know though is you do not get earth/safety from the power supply and you do have one point where everything that should have zero volts is connected (Potentialausgleichschiene). You are required to connect your heating and plumbing there.
I am quite sure nobody is taking this as advice to wire their home. Its just thinking about what the difference between two- and three-prong is. Also i do not think you get zapped in bars because i write stuff on the internet. I do appreciate the advice to not tinker with home electricity and am happy i didnt.

[Williamblake]

Well, sorry to have messed this up, thought i was saying a safe earth is a good thing but was just talking loud saying nothing.