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grounding

A

Allan Adler

Jan 1, 1970
0
I have a device that comes with an AC adaptor, with the following description
(whatever it all means):
AC ADAPTOR
CORD CONNECTED CLASS 2 POWER UNITS
MODEL: TEAD-57-122000U
INPUT: 120VAC 60Hz 36W
OUTPUT: 12VDC 2A
UL LISTED 4G38 E159614(T)

Then some diagram and MADE IN CHINA.

To me, it looks like a perfectly ordinary 2-prong adaptor. The instructions
for the device that uses it (a shop machine with motors that run off the
adaptor) say that it is important to ground it and that one needs to purchase
a 3-prong adaptor and shows pictures of how it fits into a 3-prong wall socket.

I've done that in the past when I've connected stuff directly to wall sockets.
There is usually a screw or something that one can use to connect a lead
coming out of the 3-prong adaptor. However, at the moment, I want to
plug it into a power strip and there is nothing to connect the lead
wire to. So I'm not sure what to do.

Normally I wouldn't worry about it. I would just plug the 2 prong adaptor
into the power strip and forget about the third hold. But I'm trying to
do this as carefully as possible, including confronting possibly unnecessary
details that might turn out to matter. So, with apologies in advance for
what is undoubtedly the dumbest question of the new year so far, can someone
please explain how to make sure the thing is properly grounded under these
circumstances?
 
J

Jamie

Jan 1, 1970
0
Allan said:
I have a device that comes with an AC adaptor, with the following description
(whatever it all means):
AC ADAPTOR
CORD CONNECTED CLASS 2 POWER UNITS
MODEL: TEAD-57-122000U
INPUT: 120VAC 60Hz 36W
OUTPUT: 12VDC 2A
UL LISTED 4G38 E159614(T)

Then some diagram and MADE IN CHINA.

To me, it looks like a perfectly ordinary 2-prong adaptor. The instructions
for the device that uses it (a shop machine with motors that run off the
adaptor) say that it is important to ground it and that one needs to purchase
a 3-prong adaptor and shows pictures of how it fits into a 3-prong wall socket.

I've done that in the past when I've connected stuff directly to wall sockets.
There is usually a screw or something that one can use to connect a lead
coming out of the 3-prong adaptor. However, at the moment, I want to
plug it into a power strip and there is nothing to connect the lead
wire to. So I'm not sure what to do.

Normally I wouldn't worry about it. I would just plug the 2 prong adaptor
into the power strip and forget about the third hold. But I'm trying to
do this as carefully as possible, including confronting possibly unnecessary
details that might turn out to matter. So, with apologies in advance for
what is undoubtedly the dumbest question of the new year so far, can someone
please explain how to make sure the thing is properly grounded under these
circumstances?
just use a water pipe, screw on the outlet box etc and connect it
directly to the metal case of the equipment.
 
R

Richard

Jan 1, 1970
0
Allan said:
Let me try to state the problem again a little more simply. I have an
AC adaptor from 120VAC to 12VDC. It has two prongs. The manual says
it has to be properly grounded using a 2-prong to 3-prong adaptor.

That sounds like "boilerplate", sometimes inappropriate, lawyer-driven,
statements that are stuck on all products. It doesn't seem to have any
applicabilty to your device. If you are a worrier just ground the damn
machine and get on with it.
Richard
 
A

Allan Adler

Jan 1, 1970
0
Richard said:
That sounds like "boilerplate", sometimes inappropriate, lawyer-driven,
statements that are stuck on all products. It doesn't seem to have any
applicabilty to your device.

That was also my impression. Thanks for confirming it.
 
Allan said:
What does one need the 3-prong adaptor for?
A 2-prong plug will plug into a 3-prong hole ...

Better yet, next time you're in Home Depot or wherever, see if such an
adapter is even available! There is no reason for anyone to even make
such a thing.

Richard is right, it sounds like some legal-driven requirement. If it
really required grounding, they would need to make it with a grounding
prong.
 
A

Allan Adler

Jan 1, 1970
0
me said:
what were you doing reading the manual????

It's an old habit from using learning programming languages. I tried
to quit a couple of times, but it's really tough.

In this case, the device is an 8-in-3 multipurpose machine from
Harbor Freight, model 40102.
http://www.harborfreight.com

It arrives in a (cardboard box containing a) styrofoam box and is nearly
completely disassembled into almost 100 types of parts and this astonishingly
misleading manual is the only clue you get on how to put them together.
Some parts seem to be mislabeled and at least one part number seems
not to be represented. There is an exploded diagram of the box and
its contents in the manual, but due to aliasing errors, it is almost
impossible to use it to identify anything. Thus, even determining which
part numbers are represented has been a major undertaking.

On the other hand, it costs $200 (including S&H), which is cheap compared
with what lathes and milling machines cost, and even though it is clearly
just a toy, I think I'll be happy with it if I can just get it to work.
I've put together the jig saw and the wood lathe, but some details
of the metal lathe have me stumped, and there are several other
machines I still haven't built from the kit.

The main problem with the metal lathe is making sense of how one attaches
the tool to the cross slide. Otherwise, it is completely built.

In spite of these difficulties, I'm finding the experience pretty educational.

I can't post to rec.crafts.metalworking about it because:
(1) I am undoubtedly the only person on the group who has ever demeaned himself
to such an extent as to use this toy, hence people will be asking me about
it rather than the other way around.
(2) I promised that I wouldn't post to the group until I had built something,
however small or crappy. It seems that the long discussions I was having
in the hopes of getting a better set of inexpensive machine tools
provoked some judgmental heckling that made it necessary for me to
prove I was really interested in doing some metalworking. So, I'm
proving it. This is no reflection on rcm, which I think is one of
the best newsgroups in USENET by practically every standard I can
apply, and I'm looking forward to getting active in it again.
 
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