When I plug my 12v dc power jack into the panel 5.5mm x 2.1mm socket, the metal panel becomes grounded. I have a metal case (panel) that I have drilled a thru hole in for my socket. The socket has a metal body and threads. The negative (outside) is not connected to the thread body until I push a jack in, then it is connected, thus making my panel part of the ground.
I can't seem to find a metal threaded socket that doesn't do this. A plastic body one works, except that when I tighten the nut, the plastic threads strip.
Can someone point me to one or two that will work ? Hopefully inexpensive ones. I can't find them on e-Bay.
Well, it is low voltage to begin with, so a chassis ground isn't a must have. And secondly, I don't want a dangling DuPont jumper from my breadboard touching the case and shorting out.
But to help, your problem is solved simply by using insulating plastic of fiber washers. You will have to enlarge the metal hole to fit the shoulder on one washer.
If you want to follow code, it is required that any panel of conductive material be grounded if the panel contains any electrical components. Just an FYI.
I must say that I am disappointed in some of these comments.
Yes, what you see is a disjointed set of posts, but that is because one of the forum bigwigs, who was replying to me, exercised his ability to remove his posts, leaving only mine which do indeed seem confusing. Looks like a fool talking to himself. I think that was the intention.
It is the first time I've seen someone high up in this forum (maybe he is a moderator) use the system to sabotage another member. Or maybe he is just sulking.
As for 'pearls of wisdom', neither of his comments was germane or helpful. If someone asks for advice about which shoes to buy, there is always somebody whose response is "why do you walk so much" ?
Yes, I know of the NEC requirement for chassis grounding, but I am not sure if that applies to low voltage dc. But even if it does, I expected a friendly post from someone mentioning it, as adwsystems did.
This is for my benchtop mockups. If I want to build it this way, that is my business. I appreciate a friendly caution, but not a rant. I was looking for technical advice in a technical forum.
grumpy mike seems eager to condemn without knowing the facts. Ask the skulker to repost his comments. I am attaching a photo of my final design, which he said 'never includes a breadboard'.
JohnRob & Paul, thanks for the suggestions. I will follow up.
They were, but if the OP thinks I was getting at him, that will explain his response which was puzzling me. I wasn’t blaming the OP for anything, I was just trying to explain to others the sequence of events that probably lead to the start of the thread sounding confusing.
Incidentally, in the EU the low power directive applies to voltages of 50V or under, and does not require metal panels to be grounded providing there is isolation in the power supply.
In the US, the UL inspector bounced the panel for violation of NEC by having a powered component mounted to the panel while the panel was not grounded. The new component was a 12v indicator lamp to show the power was on. Specifically this was a door but I inquired about the rest of the box. If a cable runs through a cable gland to power the panel then the box must be grounded. Unless the box is internally powered and nothing electrical touches or passes through the box then the box does not need to be grounded. So it is possible to not need to ground the box is everything is only attached to the back panel and the back panel is electrically isolated from the enclosure box.
I do not know the EU regs but do know these panels are sold worldwide.
To sell anything in the EU, it has to meet CE standards, which in the end is self certification that the product meets all the "relevant" standards. Something that has UL approval does not necessarily meet CE standards for that class of product. For example products whose main use involves electricity are required to meet the RoHS standards, sometimes called erroneously, "lead free". UL dosn't give a stuff about RoSH so will happy pass something that does not meet the standards. So despite having UL approval the product can't be sold in the EU.
Optional is relative, as in optional except when required by your customer. LOL. I do know the panels are also fully RoHS compliant. Again, I’m not fully versed on the EU requirements but it is sold worldwide so those people that do know have made sure it is EU compliant. The point was on the NEC requirement for grounding. It would appear in this case, maybe, the US is the more stringent requirement.
I realize this as drifted a little off topic but I have two thoughts I wish to share.
In the US, "ground" is the 3rd wire often called equipment ground. Not sure how that could work in the UK.
I have a number of lamps (type = sits on a table and plugs into the wall) that are UL listed, have two wire power cords and metal housings. So I guess there is more to the requirements that I am aware of.
Lamps = different UL specification. Electrical enclosures are under UL 508A or a number of others (that I can’t recall at the moment but are sitting on the shelf at work)
Optional is relative, as in optional except when required by your customer.
Yes but only because customers think it is a legal requirement. In fact a lot of technical people I have come across in the US are adment it os a legal requirement. It is not.
