(Topic ID: 85226)

Holy Flirking Cow I got 120 Volts from the rails!


By shimoda

5 years ago



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  • 48 posts
  • 20 Pinsiders participating
  • Latest reply 5 years ago by CNKay
  • Topic is favorited by 4 Pinsiders

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#1 5 years ago

So I'm just showing my son the EBD-LE I just got working as he was visiting for a bit and a brushed my hands between that and the Dr Who sitting across from it. I got a jolt but was luckily able to pull back. I knew that was electricity. Pulled out my DMM and surely enough rail to rail from the EBD to the DR Who (on two different plugs in the room) read just above 120 volts. Guess I'm lucky I just brushed and didn't get more of a shock.

At any rate, I haven't pulled plugs but considering that neither game has ever given me a shock I'm guessing before looking into it that someone swapped the wiring and that perhaps one of the floor plugs has hot wired to the common plug so that the ground for one side of the room is actually the hot for the house. Any other ideas on why my rails are wired to power more machines?

#2 5 years ago

I think you have a handle on what could be going on. Keep probing with your meter. Sounds similar to the handicap door I fixed the other day that had 115v between the handrail and the door.

#3 5 years ago

Do your plug-ins have grounds on them?

#4 5 years ago

i would start with unplugging both machine, set my dmm to continuity and probe from the rails to the wall plug (on machine) to first find what machine is shorted out and then find out why. i am not an electrician by any means but i think one of your machines has non working ground and a pinched wire somewhere on the hot side that is contacting your rails and when you touched both, current went through you to ground on the machine with a working ground.

#5 5 years ago

I know EBD is a fun classic machine, but that is a bit too exciting.
Glad you or anyone else didnt get fried.
Important to get your elec pwr (or grounding) issue fully resolved.

#6 5 years ago

Just had this problem on a 1966 EM. When it was built, some ?!$& engineer designed the neutral to be switched instead of the hot. Thus, even with power switch off, but the machine plugged in, I still got the ()$&@ shocked out of me. Check the power cord to make sure it has been wired right.

#7 5 years ago

Check each plug on the machines if it is the kind you can take off and make sure its a 3 prong and the white is in the silver screw.

Household electricity has neutral and hot. Well in theory both are hot because its AC but in the house one lead is designated neutral since in the panel it connects to ground.

You will not get shocked on the white only the black. That is why on 2 prong (in the last 20+ years) there is one plug that is wider. This is so, like on a lamp when you touch the screw part when screwing in a bulb on a live lamp you wont get shocked.

Check the plugs first. Then check the outlets.

Home Depot sells a plug tested for a few bucks that will tell you if the outlet is wired wrong.

Do these 2 things first then you can move on the machines inside (Maybe the 120 is wired backwards in the machine)

#8 5 years ago

Funny coincidence (or suspicious, whichever you prefer), the latest Pinheadz Pinball Podcast warned about this exact thing just 2 days ago.

You should have listened!

#9 5 years ago

Agree with checking the plugs and wall outlets. I have fixed a couple of games where the previous owner had clipped the ground wire and wound up with one game that had a floating ground on that machine that had a nice voltage drop to the game next to it. Depends also on how the transformer is tapped as well.

#10 5 years ago

Polarization. The game does not recognize polarization. It will work regardless. However, your body WILL feel reversed polarity in the form of a shock.

#11 5 years ago

Checked the wall plugs already. Proper continuity between neutral and ground there so has to be an issue with one of the machines. Frightening really.

#12 5 years ago

Using an extension cord, plug them both into the same duplex outlet.

Test (with meter, not your hands) for voltage between them.

#13 5 years ago
Quoted from mario_1_up:

Do your plug-ins have grounds on them?

Theoretically yes, however it is an old house and only the newer wiring I have added has three-wire romex going to it. This excludes much of the wiring in this room, unfortunately. I really need to add some wiring but can't owing to the location of the room. I mostly have to check what is there but it is starting to seem to perhaps be an issue with one of the machines, though I could see two wire wiring that was 'backwards' or reversed polarized causing the issue.

#14 5 years ago

The side rails on my Pin*Bot used to give me a nice tingle. I found it kind of relaxing. You know, like a massage.

#15 5 years ago
Quoted from vid1900:

Using an extension cord, plug them both into the same duplex outlet.
Test (with meter, not your hands) for voltage between them.

Don't know why that test didn't occur to me. 60 volts differential on the same circuit. Definitely an issue with one of the machines. Okay, so this is weird. Put another game on then tested between the three - no voltage between any and they read continuous. Plug the other back into the wall and voila 120 volts plus rail to rail. So I try continuity between grounds from one wall to the next and as I suspected, continuity chirps at say about 60 hrz chirp. Hmmmm, sound like one of those outlets is wired house hot to ground. Don't understand the 60 volt thing, but when they are on the same circuit no problem, and theoretically I shouldn't ever get 240 as long as both rails are on ground, so now I have to pull the plates on those tomorrow and try to figure out which is wired backwards. That would seem to be the issue since all machines ground to each other on the same circuit.

#16 5 years ago

In old bars with 2 wire "romex", I've seen where an idiot will put a little jumper wire from the neutral screw of the receptacle jumping over to the ground screw.

This fools those little $5 plug testers into saying that it is a functioning, grounded outlet.

Stupid and dangerous, but I've seen it more than once.

#17 5 years ago

Yeah, but the question here is, if the wiring is two wire, can I safely power these games or not. Rewiring this particular part of the house is not, unfortunately, an option. Funny thing here is that in the house power box, the neutral and ground wires are actually connected. The little cheap trick to fool testers is really a shorter version of the same thing. Usually with lower rated wire mind you.

#18 5 years ago

Looks like Shimoda narrowed down the problem.

Not trying to teach anyone else here how to be an electrician, but if you have 2 games shocking you while plugged into the same duplex, open the high voltage metal box inside the cab.

With the game off, but plugged in, check if your incoming blue wire is somehow hot with your meter.

So, meter set on AC:

One probe on blue wire, one on green. Voltage (hopefully 0v)? (if 120v blue is HOT)

One probe on brown, one on green. Voltage (hopefully 120v)? (if 0v, ground is faulty)

One probe on brown, one on blue. Voltage (hopefully 120v)?

-

If your old EM only has a 2 prong cord, replace it with a 3 prong and run the green (ground) wire to the case of the transformer.

#19 5 years ago
Quoted from shimoda:

Funny thing here is that in the house power box, the neutral and ground wires are actually connected.

Yes, that is correctly installed.

#20 5 years ago
Quoted from shimoda:

The little cheap trick to fool testers is really a shorter version of the same thing. Usually with lower rated wire mind you.

Not really, if you think about it.

The safety ground is giving an easy path for the electricity back to the panel.

The cheater wire is just trying to kill you.

#21 5 years ago
Quoted from shimoda:

Yeah, but the question here is, if the wiring is two wire, can I safely power these games or not.

Well........

Are the boxes that the 2 wires run inside of grounded back to the panel? (meter on AC, probe to black wire, probe to metal box = 120v ?)

#22 5 years ago
Quoted from shimoda:

Yeah, but the question here is, if the wiring is two wire, can I safely power these games or not.

You could also replace the duplex with a GFCI. They still trip on a fault, ground conductor or no.

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#23 5 years ago

Not sure if this may come into play for you as from how I read the posts it's a electrical outlet/house wiring problem?

I was getting jolted from a C V I had when touching rail(s) or game next to it if hand placed between them. The end result was I found that the coil for the ball release plunger on the high wire ramp had just a slight pc. of the paper wrapper missing from the coil and it was touching against the coil bracket that held it.

Just a thought for ya'. Good luck w/the resolution.

#24 5 years ago

If you have a old 2 wire system in your house (hot and neutral with no ground conductor), you can replace the old 2 wire system (12-2 w/no ground) with a 3 wire system (12-2 w/ ground) or just replace the ungrounded receptacle with a GFCI receptacle. That would make it up to code. NEC 406.3 Your neutral and ground are bonded together in the fuse box / circuit breaker panel and shouldn't be bonded anywhere else.

#25 5 years ago

Check the power cords on both machines and see if the ground pin is missing. If so that is your problem.
If not, your wall outlet on on of the machines (or both if on the same breaker are wired incorrectly)

You can buy a wall plug tester at Lowes or Home Depot to check the outlet to see if its wired right if you aren't electrically inclined.

As always with electricity, be careful. If you are a novice around 110 volts ac, be REALLY careful.

#26 5 years ago

Our electrician did shortcuts like the jumper trick- it was in a 3 way wall switch- nearly caught fire- and one in the bathroom too- had to pull all the plug s and switches and remove the dirty hacks...

what a pain...

Hope you cure your issues- GFCI are wonderful!

#27 5 years ago

Well, as I suspected from my chirping ground to ground, the suspect socket had the white and black swapped. I figured if that was the case, since ground tied back to where it should, that it meant that the socket must also be locally tied, ala Vid's description. I figure that the other sockets were similarly wired to tie neutral into ground as they test continuity between the neutral and ground, only on this occasion neutral and hot were swapped. I'll be picking up some GFCIs tonight for sure. Sure enough, pulled the socket:

2014-03-25 17.18.49.jpg

#28 5 years ago

You might have saved much more than an unpleasant playing experience by diagnosing that problem fully. Well done!

#29 5 years ago
Quoted from shimoda:

Well, as I suspected from my chirping ground to ground, the suspect socket had the white and black swapped. I figured if that was the case, since ground tied back to where it should, that it meant that the socket must also be locally tied, ala Vid's description. I figure that the other sockets were similarly wired to tie neutral into ground as they test continuity between the neutral and ground, only on this occasion neutral and hot were swapped. I'll be picking up some GFCIs tonight for sure. Sure enough, pulled the socket:

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Lousy SOBs....

#30 5 years ago

GCFI replaced that socket but I am a bit concerned that I don't know have a proper ground wire. Not really feasible to add in this location either. Any concerns using the machines here if GCFIs are installed in the requisite sockets?

#31 5 years ago

You should be fine.

GFCI will still protect you, even without the ground wire returning back to the panel.

When I do onsite service, I carry a GFCI extension cord in case the tester says the outlet is actually ungrounded.

#32 5 years ago

Man that is scary stuff. I would be re-wiring my house if I was you. People are so afraid of 220 but more people get killed by 110 than 220. I am sure it has a lot to do with more 110 out there. 110 can be deadly so be careful.

#33 5 years ago
Quoted from shimoda:

Well, as I suspected from my chirping ground to ground, the suspect socket had the white and black swapped. I figured if that was the case, since ground tied back to where it should, that it meant that the socket must also be locally tied, ala Vid's description. I figure that the other sockets were similarly wired to tie neutral into ground as they test continuity between the neutral and ground, only on this occasion neutral and hot were swapped. I'll be picking up some GFCIs tonight for sure. Sure enough, pulled the socket:

2014-03-25 17.18.49.jpg 131 KB

Wow, it's a good thing that you didn't lose your neutral back to the panel because then the neutral load would back feed through the machines ground and then YOU would be the one taking the dirty natural load when you make contact with the machines metal parts. Thats so dangerous. I see this all the time when people that have no fucking clue about electricity, they should not be touching it. Leave it to the professional.

#34 5 years ago

Sure, and think when these hack wired outlets are at the bar on the wet concrete floor.

#35 5 years ago

So what is the problem with machines? Did you check that the black is the small spade neutral white and ground pin is tied to the braid on those machines. I did not notice an answer.

#36 5 years ago

None of the outlets in my house are grounded(built in 1959) and I have no problems with machine operation or shocks from the siderails, etc.

#37 5 years ago

that is what i was thinking he showed a pic of outlet with neutral to ground but I think i missed something.

#38 5 years ago
Quoted from LOTR_breath:

None of the outlets in my house are grounded(built in 1959) and I have no problems with machine operation or shocks from the siderails, etc.

That means there is no electrical faults with your machine BUT if the hot would happen to touch the grounded metal parts on your machine, then there is a potential for a electrical shock. For example, if there is a electrical fault with your pinball machine or any appliance with a ground prong, the breaker would kick off if the receptacle was properly wired. If you had non grounded receptacle and game had a fault then the breaker would stay on. If you were to touch a faulty games metal parts ( i.e. rails, legs, coin door ) and stand on a wet concrete floor or grab a grounded metal pipe or duct work at the same time, you will feel that shock since you will be completing that path to ground. Electricity will find a path of least resistance. A GFCI receptacle will trip when a fault is detected, even if the outlet is not grounded. The GFCI senses how much current is going through the hot side and on the neutral, if there is more current going through the hot side than on the neutral side (i.e. a person being shocked due to touching a faulty machine) then that's a fault and the GFCI with trip out. All vending machines are required to have GFCI protect built in with the cord.

#39 5 years ago
Quoted from IntralotTech:

with your machine BUT if the hot would happen to touch the grounded metal parts on your machine,

Wouldn' t that be a dead short and pop breaker immediately? I guess if he was leaning against pin at the same time the hot happened to touch. ??? But not sure i am following you. I do understand GFCI but I guess a little confused on the stuff you mentioned before.

#40 5 years ago
Quoted from CNKay:

So what is the problem with machines? Did you check that the black is the small spade neutral white and ground pin is tied to the braid on those machines. I did not notice an answer.

There wasn't a problem with the pins. I knew there wasn't for sure when I plugged them both into the same socket and had no voltage from 'rail to rail'. I also figured almost immediately, knowing the age and some of what I've found in the house that it was likely that someone just wired things backwards (hot to neutral/vice versa). That is what I found. Wiring in the machines was fine. I replaced the outlet with a GFCI - properly wired. I have two more to replace the others in my house and plan to do the same.

I bought a tester but haven't opened it as I figure I'll just take it back. I'd rather do a visual inspection of the wiring in the older sockets I haven't been in as I am now concerned this might be a problem elsewhere. Additionally, I want to make sure the trick they used in the pic I posted - wire from neutral to ground on the outlet - wasn't used elsewhere so I'm going to probably have to purchase a few more GFCI outlets. Little cost considering the potential for personal harm or house fire. I've been in the house for eight years, added wiring here and there and know that there was some suspect wiring in places. I added new breakers and circuits just for my electronics in the front rooms because I was concerned about grounds but with pins drawing more amps, and players touching metal surfaces that are supposed to be grounded I want to be extra safe.

I'm really just lucky this didn't happen after I had been jogging or with people over.

#41 5 years ago

With crazy wiring, even though the breaker has the hot wire and the duplex in question has the black wire on the hot side, it does not mean that at some other junction box, someone has not mixed up the wires - reversing the hot for all the duplexes downstream.

#42 5 years ago
Quoted from CNKay:

Wouldn' t that be a dead short and pop breaker immediately? I guess if he was leaning against pin at the same time the hot happened to touch. ??? But not sure i am following you. I do understand GFCI but I guess a little confused on the stuff you mentioned before.

It would be a dead short if the hot was touching the neutral or if hot was touching a grounded conductor. I had a refrigerator that was old in my basement. I went to grab a cold beverage out it, my hand was on the metal handle of the refrigerator and was also touching my washer at the same time. I felt a shock and when I let go nothing happened. I touched it again and felt a jolt. I used my meter between the fridge and washer and had 120 volts ac. Come to find out my ground prong on my fridge was broken off and it had the hot wire pinched in the back of the fridges metal casing. My washer casing was properly grounded but the fridge wasn't. I made a path for the current when I touch both appliances. So if my fridge was property grounded, it would have instantly tripped the breaker once that wire was pinched. A breaker will not trip if a human was being electrocuted. Breaker only trip when it detects a dead short or when it senses a overload. Now if I had a GFCI on that frige, it would have tripped that GFCI, not the breaker.

#43 5 years ago

OH i get ya now. Two different outlets one wired reverse and you were touching both pins and you just completed the circuit. damn. Good thing you found that one. yeah i was thinking all the outlets would have been fine and that someone had replaced a line cord on one of the machines backwards.
Thanks for the clarification.

#44 5 years ago

Thanks for that as well Tech. Now if i had a explanation of the circumstances needed for the neutral to ground outlet hack to be such a bad thing I would be totally cool. As in my mind the neutral and ground are tied together in the panel. More please! Ready for seconds.

#45 5 years ago

Funny story. I was at the Houston Pinball Expo and I was leaning against a pin watching a friend work on someone elses machine and I accidently touched the siderails of both machines at once. It shocked and scared the shit out of me and I screamed like a girl and threw my beer all over my friend and the machine. It was embarrassing but all I could do is laugh.

#46 5 years ago
Quoted from vid1900:

In old bars with 2 wire "romex", I've seen where an idiot will put a little jumper wire from the neutral screw of the receptacle jumping over to the ground screw.
This fools those little $5 plug testers into saying that it is a functioning, grounded outlet.
Stupid and dangerous, but I've seen it more than once.

I seen a lot of crazy wiring in bars. The equipment I put in don't always work due to improper wiring, the ups that my company uses is very sensitive to grounding. If there isn't a true ground then the equipment will not turn on, until that ground is fixed. I went to a place yesterday that 16 power strips being used as extension cord, to power neons and tv's.

#47 5 years ago
Quoted from CNKay:

Thanks for that as well Tech. Now if i had a explanation of the circumstances needed for the neutral to ground outlet hack to be such a bad thing I would be totally cool. As in my mind the neutral and ground are tied together in the panel. More please! Ready for seconds.

I seen where a ground conductor was being used as a neutral in a conduit raceway. I was in a existing j-box pulling a new circuit in a walmart for some lights. I was tying in the ground to the existing ground and notice a existing lights shut off, then I notice an arch when connecting the grounds back together. That was 277 volt lighting circuit, that's not a good feeling when u touch the neutral load of a fluorescent ballast. Damn that hurts a lot.

#48 5 years ago

My first shock was when i was 7 or 8 sitting on the tiles breezeway floor screw driver in hand and just having to see what the hell was behind that plate, I think i got the screw half off and my screwdrive well ya know which hole i poked into. My Dad was cool though he mounted a bunch of boxes switches and stuff under the pingpong table downstairs and told me i could take apart as much as i wanted.

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