Possible dangerous electrical issue... Please help.

[masterchafed]

You mean the DC output to the Ramps board?

[ServiceXp]

all outputs.

[masterchafed]

The only output from the power supply was to the Ramps board, which then takes the DC voltage from the PSU and distributes it to all the other components.

But yeah, when I disconnected the DC output I didn't see much of a difference. It's a bit lower, but not by enough to say that it was anything other than background/inductance

Kind of scary then, to think that this thing may just short out and shock me every now and then. And I am absolutely sure I was shocked, and it wasn't just static, because when you discharge the static the first time you are at the same energy potential as the object that you touched, so it wouldn't have shocked me again a half second later. The shock felt almost exactly like static though (both times), so it wasn't a very strong shock.

Unfortunately I only get shocked where I have to grab to put the filament in, which means I will probably get shocked quite a bit. I haven't tried touching it since I got shocked, so I may just hook everything back up, and then try to load some filament. If it shocks me, I know something is definitely wrong.

[ServiceXp]

You need to install a GFCI outlet for that printer.. You have a problem, and until you sort it out you should not let anyone around that machine, and certainly don't leave the unit plug-in unattended.

You should not be getting cabinet voltage (> then say 500mv) to ground period. If the only thing that is plugged into that PSU is power input and the wiring is correct and your still getting high voltage to ground from any component on that machine, I would replace the power supply.

[ServiceXp]

Oh and I forgot to say... measure the outlet between neutral to ground (don't make a mistake here, if your plug is polarized it will be between the large slot and ground). Your meter should be in the mv range. Use that as your base line.

[masterchafed]

I don't understand how the components could have any voltage (aside from the voltage in the air) without the power supply plugged in. This whole situation baffles me. So you are saying, you want me to measure the voltage between Neutral and Ground to get a good baseline ground reading? Use that as my zero point essentially? Or are you saying, if that measurement is above 500 mv that the ground is not set up properly? I have a gfci plug in the kitchen, should I try that one out? Will it just trip if the ground is not correct? Or will it trip in case something goes wrong, so that I don't have to worry about getting electrocuted. Is there a solution to this problem? lol

[masterchafed]

I just tested between Neutral and Ground and I am getting about 675 mv which is about what is floating around in my machine. I do live in a dry climate, so maybe static charge is a big factor here

Did a little reading, apparently this is a pretty good value. It should be no higher than 3 volts am I correct? 3 volts on 120v AC corresponds to about a 3% voltage drop, which is acceptable, I measured .675V

[Mjolinor]

You need to either go and learn about voltage and electricity in general or you need to take it somewhere and have them look at it.

The measurements you are taking are totally meaningless and provide no information
You cannot have a positive AC voltage.
You should be measuring the resistance of things with the printer unplugged.
3% voltage drop on 120 is 116.8 volts or so.

As a general rule you cannot feel anything less than 50 volts, this is why telephone systems use 50 volts.
It is extremely rare for anything under 100 volts to cause death.
Just because your filament is not in a plastic tube does not mean you are not developing static. If plastic moves against anything at all then an exchange of electrons and ions will take place.

Is your DC negative rail connected to your house ground wire?
Does your house have an earth spike?
Is your house connected to a PME system?
Do neutral and ground connect together at your meter?

[ServiceXp]

I don't understand how the components could have any voltage (aside from the voltage in the air) without the power supply plugged in. This whole situation baffles me. So you are saying, you want me to measure the voltage between Neutral and Ground to get a good baseline ground reading? Use that as my zero point essentially? Or are you saying, if that measurement is above 500 mv that the ground is not set up properly? I have a gfci plug in the kitchen, should I try that one out? Will it just trip if the ground is not correct? Or will it trip in case something goes wrong, so that I don't have to worry about getting electrocuted. Is there a solution to this problem? lol

1) Don't pay any attention to any (voltage) values measured with the unit unplugged, it's just a waste of time and is of no value.
2) Used as your base line (empty socket). So values above that is where your attention needs to be focused on.
3) It will do both. The GFCI will monitor the current between Line and Nueteral, if there is any imbalance it will fault and break the circuit to the machine. I suspect (if you truly have a component leaking voltage) your printer will just trip the GFCI when used.

I just tested between Neutral and Ground and I am getting about 675 mv which is about what is floating around in my machine. I do live in a dry climate, so maybe static charge is a big factor here

Did a little reading, apparently this is a pretty good value. It should be no higher than 3 volts am I correct? 3 volts on 120v AC corresponds to about a 3% voltage drop, which is acceptable, I measured .675V

Forget about the base value, there are a lot of reason that number will be higher and lower at any given time. You are more interested in using that value as your base. I would think, (if it is truly static electricity) after you shunt to earth (discharge the static build up) you would not get repeated shocks. I don't know your setup, but generally static doesn't build up to those levels given the surface area of the filament and tubes. You are much more likely to build up on your body just walking to the machine on carpet. Not only that, I don't think you would be measuring AC voltage with your meter to ground when the unit is running if this was a static issue.

You need to either go and learn about voltage and electricity in general or you need to take it somewhere and have them look at it.

As a general rule you cannot feel anything less than 50 volts, this is why telephone systems use 50 volts.
It is extremely rare for anything under 100 volts to cause death.

Depending on type (AC vs DC), you can most certainly feel current to ground with much lower voltages. It just depends on how well you are grounded and the current involved. I've had the piss shocked out me with 12vac before. (HVAC/R HA Tech.) As you know, voltage is almost irrelevant in terms of fatalities. The body type, and area of body being effected with the amount of amperage plays a much greater roll in life or death.

[Mjolinor]

1) Don't pay any attention to any (voltage) values measured with the unit unplugged, it's just a waste of time and is of no value.
2) Used as your base line (empty socket). So values above that is where your attention needs to be focused on.
3) It will do both. The GFCI will monitor the current between Line and Nueteral, if there is any imbalance it will fault and break the circuit to the machine. I suspect (if you truly have a component leaking voltage) your printer will just trip the GFCI when used.



Forget about the base value, there are a lot of reason that number will be higher and lower at any given time. You are more interested in using that value as your base. I would think, (if it is truly static electricity) after you shunt to earth (discharge the static build up) you would not get repeated shocks. I don't know your setup, but generally static doesn't build up to those levels given the surface area of the filament and tubes. You are much more likely to build up on your body just walking to the machine on carpet. Not only that, I don't think you would be measuring AC voltage with your meter to ground when the unit is running if this was a static issue.




Depending on type (AC vs DC), you can most certainly feel current to ground with much lower voltages. It just depends on how well you are grounded and the current involved. I've had the piss shocked out me with 12vac before. (HVAC/R HA Tech.) As you know, voltage is almost irrelevant in terms of fatalities. The body type, and area of body being effected with the amount of amperage plays a much greater roll in life or death.

You are going to be confusing this guy. This needs sorting with it unplugged.

Current cannot flow without voltage and under normal conditions you need at least 50 volts for it to flow through a human. The most important thing regarding mortality rate is the path the current flow takes not the current. 2 ma through the heart will easily stop it dead but finger to finger on the same hand 3kv will be little more than a tingle and around 2ma will flow .

Death from electrocution is almost always where the current path goes through the heart. If you die from a non-through the heart shock then it is a terrible death that doesn't happen for days after the accident. Death occurs because the muscles are cooked and you will wake up feeling fine, over a few days your body begins to ache and you become unable to move. Fairly quickly after that you will die because your blood has congealed.

This is why they teach you to keep one hand in your pocket when messing with live cables. It is very unliklely that current will pass through the heart if you do not have the voltage across your chest.