DANGER WILL ROBINSON DANGER Dedicated ground outlet


(Jude Marleau) #1

I am standing up and declaring that I am wrong and could be DEAD wrong with my previous “advice” about my dedicated ground circuit. In my posts about electrical circuits and/or poorman’s enclosure I described how I built a dedicated ground circuit. Now I stand on the purpose of this ground circuit because it provides a separate place to ground the machine’s frame, the vacuum hose and even a wrist strap if I was so stupid, all back to the same ground. The outlet has each pole wired to the ground of the outlet so there is absolutely no electricity available to that outlet. But I just realized how dangerous that could be. I never planned on unplugging that ground plug which has a bare ground wire form the frame and the vacuum hose to each prong connecting each bare wire to a bare wire within the socket itself. I had to unplug it to move the machine out of the enclosure to work on it (maintenance). Now what will happen IF I plug that ground only plug into the wrong outlet. I will be DEAD wrong. DO NOT SET UP OR MAKE A DEDICATED GROUND CIRCUIT. Sorry for shouting but maybe I need to hear it also. I am still going to use my dedicated ground circuit but I am immediately going to hom depo to get a dryer plug and outlet for that purpose that is absolutely different from ANY other plug in my workshop. I DO NOT RECOMMEND THIS TO ANYONE!!! I may have been certified to design an electrical design for an entire city a long time ago but WOW was I wrong here. I hate social media and this is only one of two forums I belong to because of stupid advice anyone can give and not be responsible for. I respect the members of this forum and even though this may decline my respect from those experienced CNC machinists I know declaring this error is more important. It may be better that any reply from a noobie be background colored in yellow for caution sacks. Anyways BE CAREFUL about how you read advice. I am sorry. I no longer feel I should give advice or opinion on other than woodworking which I’ll probably keep to myself. That’s the other problem with social media, you can get carried away talking (not meaning to but) and sounding like you are an expert and some poor sole will take your advice and get hurt. To paraphrase one highly respected member here “put a fork in me, I’m done…”


(Roger Newmon) #2

Advice should always be taken at face value and then apply common sense to it. But these days common sense is less common then it used to be for sure!

I agree if you were to plug one of those plugs in because of your wiring design it would be a mistake. On the other hand you could re-wire the plugs to only use the correct ground terminal on the male side or you could use special plugs that will not fit any where else as you mention.

Don’t worry about it too much, many people post mistakes. Some are spotted, many go un-noticed. Just try to keep your self honest like your are doing from time to time and that’s all we can each do. No one has the perfect solution to any problem, we are just not designed to be perfect.


(James Carter) #3

Actually, having dedicated ground circuits are a good thing, if implemented properly. I worked in a chemical plant, and we had grounding circuits for the barrels (to avoid static sparks).

The outlets were bright green, and clearly labelled. Perhaps you should do that too, as anyone with even a little electrical experience will recognize it as a ground circuit. (green).

I have already considered a dedicated ground for my Nomad, as it seems to be extremely sensitive to static shocks. I’ve stopped the machine a few times simply by touching it. Yes, the ground on the plug is active, but the frame of the machine doesn’t seem to be grounded. I need to look deeper into the issue.


(Roger Newmon) #4

I think to his point, it’s not the outlet that is the issue it’s the male plug side. If you have ground connected to any of the other prongs in the male plug side and you plug that into a live socket you will be in trouble!


(Jude Marleau) #5

Yes Roger, that is exactly the point ! I did immediately change the outlet and the plug to a dryer socket and one that is also different than my 220 table saw socket even though the table saw is on the other side of the workshop. So there is no way I can accidentally plug it into a live socket. Thanks for the support, this turkey feels over cooked. To James’ point, I worked in a gas plant for many years and all they did was everyone kept their car keys in their ignition. Really they did, and a couple times all I saw was the foreman tearing out of the plant to get to a hilltop about a mile away to see (with his binoculars) what made the loud noise he had heard. It’s the long term damage from the constant gas fumes that has me disabled now and causes the memory laps and loss of mental focus which is why I need a physical way to distinquish the ground plug from the live circuits (colors and signage will depend on my recognizing and remembering) . The good thing is that this CNC adventure is so mentally intense that it causes the brain to rewire bad connections and all though it is slow, I have seen definite improvements. Worrying and fretting about the past is useless, be content , adapt , improvise and overcome .


(mikep) #6

Please don’t use a dryer socket for this…they’re pretty common on welders. You’re just going to pi$$ off the next guy who thinks you have an awesome 220 socket ready for him. A plain old 3-prong plug, nothing connected to the spades, will do just fine. Can plug it into a “live” circuit, and nothing untoward will happen.


(Jude Marleau) #7

Nothing against welders Mike, but if I sell my house and move, I’ll be taking my shop with me. YMMV