Grounding machines

[chrisg]

I know that there has been some discussion in the past concerning grounding of machines. I have owned six pachislos, and I have felt a tingle on the case on all of them. What I am looking for is someone to help me with directions to install external grounding wires. Past threads have not answered my questions to the point where I feel comfortable doing this.

Any help will be very much appreciated.

[luckydog]

maybe your outlets aren't grounded properly.

or static from a rug???

I've got machine all over my house and have no problems.

[Tulsa]

I can't say I've ever had any problems either.

[arbycoffee]

you have grounded wall jacks ?

[chrisg]

My house is only 12 years old. I keep my machines in my remodeled basement and in the garage. Same feeling in both locations. While the plugs are grounded, they are not of the variety with the test and reset buttons. By the way, this tingle only comes when I brush against part of a machine lightly.

[logicprobe]

On the machines that I converted, I used an old computer power cord. You can usually find these just lying around any ol' computer lab. Even if they're still connected to computers, just wait until nobodys looking. :smirk:

Anyway... cut off the female end of the cord that plugs into the computer, strip back the black insulation sheath from the cable, and that will leave you with three wires... with white, black, and green insulation.
The black and white wires will go to where your two wire power cable is now connected... if it's a model with a transformer, they lead to the primary side of that. If it's a model with a power supply, then you'll probably need to remove the old cord from a connector that attaches to the PS. Be sure to leave enough room to strip back the insulation when you cut it.

The green wire of the new power cord is the ground. This you want to connect to a spot on the metal chassis. I've found that crimp type terminals work just fine... you can pick up an assortment at Radio Shack. Strip back a bit of the green insulation, crimp a connector on it, and find a good screw to attach it to.

If your door isn't already connected to a metal chassis somehow on the frame (usually with a braided ground wire), you might also need to run a wire from the door to that chassis spot you just grounded. That should draw any stray voltage to ground... and not into you.

People react differently to that stray voltage. Some with very dry skin don't notice it at all. I knew a guy that could hold 110v live wires... one in each hand... and his skin was so dry it wouldn't bother him (hmmmm.... come to thnk of it, I haven't seen him around lately! ) That's pretty rare, AND stupid.
When my kids were playing my pachislos in my basement, and when they were in their stocking feet, they used to feel it all the time. Even if they had shoes or slippers on... one of my machines sat on a metal stand, and just touching the stand with one hand (or foot), and the case with the other hand would give them a little bite.

Better to be safe than sorry.

[arbycoffee]

one may not need it, but it never hurts and it don't eat no hay or drink water.

[chrisg]

Thanks to everyone so far. Logic, that is a great start for me. I have seen those braided wire cords on the door and wondered what it was for. Is there any way to run a thin grounding wire and leave the existing plug in place?

[logicprobe]

You probably could... but officially, I'd have to recommend the other way, for sure.

If you want to give it a try, use that same green wire from a three-prong plug... just don't connect the white and black. Tape white and black off, separately first, then together, for safety sake.
Strip back the green wire, and connect the chassis grounds of the machines to that with your individual wire(s).
Another spot that you can sometimes use for a ground is the metal screw in the outlet faceplate. You could try to back that out a little, wrap a wire around it, then tighten it back in. Take the other end of the wire to your chassis. If the outlets are properly wired, that screw... if it's metal... should be a connection to ground.

And... OF COURSE... make sure none of this stuff is plugged in when you're doing it. I think that's obvious, but just wanted to add that disclaimer.

Let us know if it helps!

[chrisg]

Thanks!

[slotter]

A good thread to read thru re grounding:

http://www.pachitalk.com/forums/showthread.php?t=3480

[chrisg]

I thought I'd pass on what I did for grounding my machines. Please tell me if this was adequate, as I don't want to fry myself. I opted for an external wire. I ran 16 AWG primary wire (rated to 600 V)with crimp-on ring terminals fastened to either end. I fastened one end to an otherwise unused screw near the power supply and the other end to the screw on the plug faceplate. It appears to have worked. Am I safe with this?

[arbycoffee]

…fastened one end to an otherwise unused screw near the power supply… Am I safe with this?

Do you mean you have this metal in contact with the metal of the power supply ?

[Tulsa]

Is the wall plate plastic? Is the screw painted? Like Arby mentioned, it's needs to be metal on metal.

[chrisg]

Plastic faceplate, but I think I'll buff the outlet screw with a little steel wool to make sure there is good contact.

[napster]

Time to add my 2 cents. Logicprobe is right...each machine should have its own 3 prong plug attached to it. This is the only true proper way to do this. But if you feel the need to ground the machines together then take a long enough piece of wire and run it inside the machine. Strip back enough insulation and connect it to your main chassis via a suitable screw. Continue this wire to the next machine and repeat this process until all of your machines are "daisy chained" by this one wire. Go to the hardware store and invest a couple bucks on a replacement plug. Connect this wire to the ground terminal (The lower round one, NOT the 2 side by side spade terminals) Put the cover back on so that no screws are exposed, and plug into the wall.

The reason why some people feel this tingle and some people don't is due to the "resistance" that exist between the person and the machine. Electricity always takes the path of least resistance to ground. There is a certain amount of "Current Bleed" that comes off of these machines...and your body is being used as a ground wire that satisfys the rule "Least resistance to ground" You increase the resistance in your body by wearing shoes and socks and standing on carpet. These are the members that don't feel the tingle. (But its still there) I live in a very humid area of the country, and play my machines in the garage while in bare feet. Needless to say that all of my machines really bite! When you ground the machine properly, the ground wire becomes the path of least resistance, not you. I never understood why the venders didn't bother to ground these machines. I doubt that these machines would ever get a UL approved rating. But as I said before, Logicprobe is right...You should consider grounding each one by itself. Years ago when I was in electronic school we had a saying that simply stated "When in doubt, ground it" Grounding protects you from being the ground if something shorts out. Hope this helps.

[photos8484]

There are plugs available that have 3 buttons on the back that light up when plugged in to see if the wires are hooked up correctly. Electric shops carry these, I think walmart & sears do, too. If the wires aren't hooked up right, it will glow red, if they are, it will glow green. You would be surprised at the amount of wires that could be hooked up incorrectly. These things are only a few dollars & good insurance.

Bottom line: IF IT TINGLES, SOMETHING IS WRONG!
!!!

And ALL SIX tingle???

[napster]

ALL twelve of my machines tingle. You notice it more when you lightly brush up to the metal parts of the machine. The device that Photos8484 is talking about is a good idea for checking your wall recepticle. I had one for years and had found some miswired outlets in my lifetime. But the problem is still coming from a machine that is not grounded. Even if the neutral and hot were reversed at the outlet...this would not affect the operation of the machine. All of my machines use nonpolorized plugs...Which allows me to flip the plug around and insert it the other way. (Which would be the same as reversing the neutral (white) and hot (Black) wires) Those polorized plugs are used mainly for "so-called" hot chassis. Since the machines have transformers in them, it provides isolation (For you) from the 110 volts at the outlet. Grounding the machines will solve the tingle problem. I would bet that a lot of people have this problem.
BOB

[luckydog]

I don't get any tingles from my machines!!!!

Is that because I'm too old to feel them????

[cwstnsko]

I only feel the tingle on my 100V machines, none of the 24V machines with transformers bleed enough voltage to notice. All of my 100V machines bleed enough voltage for me to feel. The 1st time I noticed the tingling was when I happened to lightly brush my cheek against the door frame when loading/unloading tokens. I added a ground wire and the feeling completely went away. Now I ground all of my machines by either replacing the power cord with a 3-prong cord, or adding a ground wire to the outlet screw as described above.