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2-prong electrical devices

R

Ralph Mowery

Jan 1, 1970
0
Can 2-prong electrical devices always be plugged into an outlet either
way? If so, why is this?
They can if the plug will fit. Some have one side of the plug bigger than
the other . This means they can usually be plugged in only one way.

For AC it does not mater which side is used as the current is reversing 60
times a second. It does make a small safety differance sometimes incase of
electrical problems.
 
Ralph said:
They can if the plug will fit. Some have one side of the plug bigger than
the other . This means they can usually be plugged in only one way.

For AC it does not mater which side is used as the current is reversing 60
times a second. It does make a small safety differance sometimes incase of
electrical problems.

Hey! I must have slow electricity, because mine only reverses 50 times
a second. What's the skinny on that, Ralph? Also, do airplanes go
faster because their electricity reverses 400 times a second?
 
R

Ralph Mowery

Jan 1, 1970
0
Hey! I must have slow electricity, because mine only reverses 50 times
a second. What's the skinny on that, Ralph? Also, do airplanes go
faster because their electricity reverses 400 times a second?

Slow electricity for slow countries.
Yes the planes do fly faster because of 400 reverses per second.
 
P

Puckdropper

Jan 1, 1970
0
They can if the plug will fit. Some have one side of the plug bigger
than the other . This means they can usually be plugged in only one
way.
Agreed.

For AC it does not mater which side is used as the current is
reversing 60 times a second. It does make a small safety differance
sometimes incase of electrical problems.

My mileage has varied on this. My Dad's tube amp has to be plugged in
properly to prevent electric shock to the user. Yes, it still works fine
with the plug reversed, but good luck turning it off!

It makes a BIG safety difference.

Puckdropper
 
A

Alan B

Jan 1, 1970
0
My mileage has varied on this. My Dad's tube amp has to be plugged in
properly to prevent electric shock to the user. Yes, it still works fine
with the plug reversed, but good luck turning it off!

The hazard here is caused by the user becoming a path from the switch to
ground. It sounds like the case on the amp is tied to one of the AC legs,
so it is crucial that that leg be the neutral (unless the user could be
certain that he or she has sufficient insulation from ground). The *best*
way to handle this is to isolate the case and run a three-prong plug with
the case grounded. The design of the amp might rule that out as an option.
It makes a BIG safety difference.

Polarized AC plugs are making use of the NEC code that requires the neutral
side to be tied to earth ground in the main household circuit breaker
panel. Non-polarized plugs can be used for things like rectifiers, where
the AC in will not normally be accessible by the user. Things like floor
and table lamps have, in the past, used non-polarized plugs, but that
leaves the way open for a shock hazard when changing a bulb on a live
circuit. The three-prong plug is used when the device has a case that
should be grounded, and carry no normal current.
 
R

Rich Grise

Jan 1, 1970
0
My mileage has varied on this. My Dad's tube amp has to be plugged in
properly to prevent electric shock to the user. Yes, it still works fine
with the plug reversed, but good luck turning it off!

It makes a BIG safety difference.

I once did a sort of demo of this effect; I was a teenager, with some
other teenagers in a big garage with a moist concrete floor, and we
were all barefoot, and the guy was getting hum through his guitar amp.
I said, "Oh, just turn the plug around." Which I did, and while standing
on the moist concrete barefoot I reached out with a flourish and laid my
hand across the guitar strings. BZZZZZZAW!!!! It seems the original hum
wasn't from a backwards plug.

Cheers!
Rich
 
R

Rich Grise

Jan 1, 1970
0
Hey! I must have slow electricity, because mine only reverses 50 times
a second. What's the skinny on that, Ralph? Also, do airplanes go
faster because their electricity reverses 400 times a second?

When I was in the Air Force, they used to send guys out to check the box
of dirt in the airplane's tail that they use for Earth ground. ;-)

Cheers!
RIch
 
M

Michael A. Terrell

Jan 1, 1970
0
Hey! I must have slow electricity, because mine only reverses 50 times
a second. What's the skinny on that, Ralph? Also, do airplanes go
faster because their electricity reverses 400 times a second?


So, you are using 25 Hz electricity?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
Michael said:
So, you are using 25 Hz electricity?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

OK - you got me fair and square on that one. Loose language. Although
I'm in (good? not sure!) plentiful company, The Arizona Collaborative
for Excellence in Preparation of Teachers says in their electrical
safety course for teachers in that state:-

http://acept.asu.edu/courses/phs110/ds/appendixC.html

The rate at which the current reverses direction is set by the power
company, and in the U.S. is (unfortunately!) 60 times each second (60
cycles/second or 60 Her). Hence we refer to the electric power
delivered to our homes as 120 volt, 60 Hz electric power.

Wisconsin too...

http://www.uwsp.edu/cnr/wcee/keep/Mod1/Flow/watts2.htm

Electrical generators in power plants throughout the United States
produce alternating current that reverses direction 60 times per
second.

But not in Virginia...

http://howthingswork.virginia.edu/page1.php?QNum=382

However, the alternating current in the United States reverses 120
times a second in order to complete 60 full cycles each second. ...

Is this a North-South thing?
 
M

Michael A. Terrell

Jan 1, 1970
0
So, you are using 25 Hz electricity?

OK - you got me fair and square on that one. Loose language. Although
I'm in (good? not sure!) plentiful company, The Arizona Collaborative
for Excellence in Preparation of Teachers says in their electrical
safety course for teachers in that state:-

http://acept.asu.edu/courses/phs110/ds/appendixC.html

The rate at which the current reverses direction is set by the power
company, and in the U.S. is (unfortunately!) 60 times each second (60
cycles/second or 60 Her). Hence we refer to the electric power
delivered to our homes as 120 volt, 60 Hz electric power.

Wisconsin too...

http://www.uwsp.edu/cnr/wcee/keep/Mod1/Flow/watts2.htm

Electrical generators in power plants throughout the United States
produce alternating current that reverses direction 60 times per
second.

But not in Virginia...

http://howthingswork.virginia.edu/page1.php?QNum=382

However, the alternating current in the United States reverses 120
times a second in order to complete 60 full cycles each second. ...

Is this a North-South thing?


Only of the zero volt base line. ;-) As for me, I was born in
Kentucky, but grew up in Ohio. I have lived in Alabama, Alaska, and
Florida, as well.

I have read and written too many technical papers to let errors like
that continue unchallenged. My teachers always got upset when I raised
my hand to point out an error in a textbook, or a lesson. Thanks for
the links to the bad data. I love to point out bad websites to the
authors. Some are very stubborn and refuse to correct their pages, while
others quickly make the changes and thank you for politely pointing out
their mistakes.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
E

ehsjr

Jan 1, 1970
0
Michael said:
So, you are using 25 Hz electricity?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida


OK - you got me fair and square on that one. Loose language. Although
I'm in (good? not sure!) plentiful company, The Arizona Collaborative
for Excellence in Preparation of Teachers says in their electrical
safety course for teachers in that state:-

http://acept.asu.edu/courses/phs110/ds/appendixC.html

The rate at which the current reverses direction is set by the power
company, and in the U.S. is (unfortunately!) 60 times each second (60
cycles/second or 60 Her). Hence we refer to the electric power
delivered to our homes as 120 volt, 60 Hz electric power.

Wisconsin too...

http://www.uwsp.edu/cnr/wcee/keep/Mod1/Flow/watts2.htm

Electrical generators in power plants throughout the United States
produce alternating current that reverses direction 60 times per
second.

But not in Virginia...

http://howthingswork.virginia.edu/page1.php?QNum=382

However, the alternating current in the United States reverses 120
times a second in order to complete 60 full cycles each second. ...

Is this a North-South thing?

Maybe the seconds are longer/shorter depending on
location. Or electricity is faster in the south
than it is in the north?

Ed
 
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