Chassis Grounding

**dream beamz** · 12-03-2007, 08:14

Originally Posted by steve-o

I'm not running a gas laser here, just a small 1/2 watt diode/dpss so a couple of amps @120V thru the cord should give me plenty of current to work with after the transformer/ psu coverts it to lower voltage/ higher current.

BTW- I looked around the house to see the appliances that run 2-wire ungrounded and there was the stereo receiver, dvd burner, vcr, a box fan, george foreman grill and several other things I dont have time to list right now..

Right, but I thought your concern was the sturdiness of wire. The plug and accompaning wire would take care of that for you. Anyhow.

Your electronic equipment is not a stereo, vcr or anything else you just listed. It is a highly sensitive laser and must be grounded unless you are using it in a test environment for a short period of time. Please, take everyones advice here, ground it

**steve-o** · 12-03-2007, 10:26

I just like the "feel" of the wire I have.

Yes I know that grounding is usually the best practice (I've been working in electronics for 33 years , I have a degree in electronics, and work with industrial Delta 230/ 480 VAC) However, grounding is not always necessary, and sometimes hazardous under certain conditions. I've seen 2 pieces of "grounded" equipment at very different and hazardous potentials. It depends on the quality of the facility wiring, maintenance on that wiring and the equipment used. Also, I know that a vcr is not the same thing as a laser projector

but the point is some do not have to be grounded because all of the high voltage circuitry is isolated/ insulated from the chassis and there is only low voltage is present exposed inside the metal enclosure; therfore no risk of shock, and sometimes even safer, depending on the circumstances. Not all people know what they're doing concerning electrical constuction.

**JimBo** · 12-03-2007, 12:59

Originally Posted by steve-o

I just like the "feel" of the wire I have.

Yes I know that grounding is usually the best practice (I've been working in electronics for 33 years , I have a degree in electronics, and work with industrial Delta 230/ 480 VAC) However, grounding is not always necessary, and sometimes hazardous under certain conditions. I've seen 2 pieces of "grounded" equipment at very different and hazardous potentials. It depends on the quality of the facility wiring, maintenance on that wiring and the equipment used. Also, I know that a vcr is not the same thing as a laser projector

but the point is some do not have to be grounded because all of the high voltage circuitry is isolated/ insulated from the chassis and there is only low voltage is present exposed inside the metal enclosure; therfore no risk of shock, and sometimes even safer, depending on the circumstances. Not all people know what they're doing concerning electrical constuction.

With your experience and qualifications you should know the reasons why grounding is used.
You should also know that items that are class 2 (double insulated) are not just boxes without the earth connected.

Jim

**steve-o** · 12-03-2007, 14:29

Yes, I know this.. Oh nevermind, forget this thread..
Go over to 'joke a day' It made my day

**steve-o** · 12-03-2007, 15:02

For some reason I cant let this go..
OK -I could draw a picture but I aint gonna..
Picture 4 "wall -warts" in an enclosure powering 3 lasers and the scanners.
No High voltage except the120/240 vac entrance which is heavily insulated/ isolated with big thick cord and FOUR layers of heatshrink and electrical tape hi-potted to 20KV. The 'on' key-switch is a 4PST low voltage relay. Got the picture? Why would we want to ground this enclosure?

Arrrgggghhhh!!!

**allthatwhichis** · 12-03-2007, 19:05

Steve, I may be off base, but did you see my projector at SELEM? I had a power strip that I plugged into a wall and had a wall wart(maxyz), two plugs (1/blue dpss, 2/green dpss), plug for the scanners, and one for a psu for a couple of fans.

spec and DZ rewired it to a nice bus bar to hook up to a plug on the back of the projector, which had a ground. I wanted them to do it so I could get rid of the wall warts and extra plugs AND the power strip. The bus bar acts as a power strip and is grounded. To me it looks a lot better inside and I guess it is safer for the delicasees in there...

But ride on man and take some pictures when you are done.

**steve-o** · 12-04-2007, 05:09

Sorry I'm drilling this topic into the ground..

I'll let it go now, thanks for all the good advice, y'all

**JimBo** · 12-04-2007, 05:43

Originally Posted by steve-o

For some reason I cant let this go..
OK -I could draw a picture but I aint gonna..
Picture 4 "wall -warts" in an enclosure powering 3 lasers and the scanners.
No High voltage except the120/240 vac entrance which is heavily insulated/ isolated with big thick cord and FOUR layers of heatshrink and electrical tape hi-potted to 20KV. The 'on' key-switch is a 4PST low voltage relay. Got the picture? Why would we want to ground this enclosure?

Arrrgggghhhh!!!

When the laser has been sitting in the garage for a week at 10 Celsius then you take it into your nice warm living room at 24 Celsius all of the metal is going to get condensation on it, I wouldn't want that to be without an earth would you?

I know you can say that you would never do that, you will always keep the laser at room temp etc... , accidents happen too, you may knock a drink over near the projector....

See where I am coming from?

Jim

**steve-o** · 12-04-2007, 06:16

ha ha ha, ha ha, ha ha ha, ha ha

.................................................. .......................

**steve-o** · 12-04-2007, 14:36

Well, I showed up at SELEM with my ungrounded argon, my ungrounded projector and my ungrounded TEA arclamp which I gave to Steve.. say, has anybody heard from MixedGas lately?

I guess I wont be getting my ungrounded self invited to the next Selem I suppose -heh-...

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