No Ground Wire(earth) - Dangerous? - Page 1
Forum section: electronics / beginners

author: THATguy
author_rank: Regular Contributor
timestamp: November 19, 2016, 03:12:23 am
content: I have a small Fluorescent light (as seen in the attached picture).It is quite old, has a metal housing, but when I connected a plug it works.However the cord I used does not have a ground wire (there is a place for ground wire inside of the light housing.Because there is a switch on the power cord, there is no reason for anyone to touch the metal housing.The whole thing is mounted on wood (as seen in photo), and that will be tied to a concrete pillar as a bedside light.Is it safe?Should I connect a different cord that has a ground wire?I do have a multi meter that I can test for any current on the metal housing.

author: SeanB
author_rank: Super Contributor
timestamp: November 19, 2016, 05:14:32 am
content: Best to replace the cord with a grounded one, and use a cable gland where the cord goes in to act as strain relief. You do get inline light switches that will accommodate small diameter 3 core cables, and there you only switch the active ( brown) conductor, the others passing through in a internal slot.Grounding the fixture is good from a safety point, and also has an improvement in enabling the lamp to start easier with the capacitive coupling along the tube length, though those small 8W tubes do have a short life, simply because they have a very low mercury dose, and tend to have a lot of power cycles in a bedside lamp role, which strips the cathodes rapidly.however that tube in there is easily 30 years old, and probably is either Sylvania or GE made, but those plants closed 20 years ago.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: November 19, 2016, 07:45:47 am
content: Quote from: blueskull on November 19, 2016, 06:13:03 amIt's not double insulated so it's not legal to install it anywhere in Au/Nz.Chuck it out.get one of these or similar for $20.00http://sal.net.au/led%20downlights/led%20residential%20downlight/wave/s9065/product-detail.aspx

author: Gyro
author_rank: Super Contributor
timestamp: November 19, 2016, 10:01:47 am
content: Sharp eyesYes, that's a cable from a Hitachi appliance, unfortunately it is re-used. That light fitting wouldn't have originally come with a cable. The fitting will almost certainly have a choke and internal wiring that are not double insulated.

author: Zbig
author_rank: Frequent Contributor
timestamp: November 19, 2016, 11:28:50 am
content: No offence, man, but all the safety issues aside, you were actually gonna install THAT as your bedside lamp? It's fugly and disgusting

author: Zero999
author_rank: Super Contributor
timestamp: November 19, 2016, 01:38:19 pm
content: Quote from: THATguy on November 19, 2016, 03:12:23 amIf there's a terminal for the protective earth conductor, then it isn't double insulated and needs to be earthed to comply with the relevant safety standards.QuoteEven if it's installed out of reach from anyone, it still needs to be earthed because someone might climb a ladder and touch it when changing the tube. Yes, I know it's best practise to disconnect the power when changing a tube bot not everyone does that and it should be perfectly safe to do so, if the lamp fitting is correctly wired.

author: Seekonk
author_rank: Super Contributor
timestamp: November 19, 2016, 08:50:04 pm
content: I know electrical safety is a hot topic, but it isn't that easy to get electrocuted. Considering the millions of the general public using electricity every day with legacy products of almost no standards. The number is rather small and 90% of the people killed are professional electricians. You are thousands of times more likely to be killed by your own doctor. They are what you should be afraid of.

author: THATguy
author_rank: Regular Contributor
timestamp: November 19, 2016, 09:15:53 pm
content: Quote from: SeanBOh yes it does seem to start slower, originally I tested with grounded cord. Changed to cord with switch.Amazing that you determined the age of the tube from that one photo!I just want to use these tubes up, it is for in a work shed (yes with a bed for the overworked).Guess I'll build a plastic housing. And make a plastic protector for where the cord goes out through the metal housing.Quote from: Hero999Yes. That is a very good point.Here is how I mounted it.A look inside of the housing.And another bulb I found, saleable? Or just a good source of Tungsten and Halogen gas (I'm a chemist/smelter).This one won't fit anything I can see around.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: November 19, 2016, 10:11:25 pm
content: Quote from: blueskull on November 19, 2016, 07:53:03 amThrow that POS out. Smelt the fu## out of it. It wastes energy, looks bad, the light output will flicker and will look bad, it wont work in cold weather, it takes a few goes to start up. Did someone mention it isn't safe?For $20 + a 90mm cut out, u will have a beautiful efficient safe light, that is even dimmable for those romantic evenings if you want it.

author: Gyro
author_rank: Super Contributor
timestamp: November 19, 2016, 10:13:45 pm
content: Interesting styling.Yes, that should be grounded. Luckily there seems to be a 3 way terminal block for just that purpose (check that the 3rd connection actually is chassis).

author: SeanB
author_rank: Super Contributor
timestamp: November 20, 2016, 06:59:14 am
content: Thorn, so it is made sometime in the late 1960's to early 1970's, before they became Thorn EMI.

author: tautech
author_rank: Super Contributor
timestamp: November 20, 2016, 07:16:34 am
content: @ THATguyAny appliance with a metal housing must be grounded. Period.Ignore this law at your or your loved one's peril.Fix it FFS.

author: _Andrew_
author_rank: Regular Contributor
timestamp: November 20, 2016, 07:31:37 am
content: Yup three terminals. You will probably find that there is a little metal tab coming up from the case in to the third terminal that should be connected to ground. the cable presently on the lamp fixture was most lightly purchased separately and fitted to it.I would be also concerned with were the it is mounted as it is not with in an enclosure. I could be very vulnerable to being bashed and broken. Fluorescent tubes use mercury vapor in them which is not good for you if it gets out.

author: THATguy
author_rank: Regular Contributor
timestamp: November 21, 2016, 08:45:25 am
content: Actually it works pretty well.But, yes it won't stay mounted in it's current form.Thanks for all your help.

author: EPTech
author_rank: Regular Contributor
timestamp: November 21, 2016, 09:04:06 am
content: Hi there,Actually even the metal shed needs to be grounded. If you do not have grounded outlets in the shed, you can simply drive a copper or galvanized steel stake in the ground and hook the shed and ground terminals of your outlets to it locally. Normally this makeshift local earth also has to be connected to your main installation. Those are called equipotential interconnects but they are not mandatory in some countries. If the installation does not have an RCD, earthing is kind of pointless. The lather is of course DANGEROUS and ILLEGAL!Happy building.