220 volt 3-wire vs. 4-wire
 

I have a 220-volt electric dryer with 3-prong plug going into a 3-prong
receptaclet (2 blades on a 'V', and third L-shaped prong).
Do newer electric dryers have a 4-wire plug with a ground?
Would I have to replace the 20-year-old 3-prong receptacle?
Just technically speaking, could the ground prong on the male plug be cut
off to fit the old outlet (similar to what people of done for years on
110-volt stuff). Or is the wiring for 4-wire 220 volt completely different
because of 2 hot wires, neutral, ground, etc.?

220 volt 3-wire vs. 4-wire
 

"M.Burns" wrote in message
...
I have a 220-volt electric dryer with 3-prong plug going into a 3-prong
receptaclet (2 blades on a 'V', and third L-shaped prong).
Do newer electric dryers have a 4-wire plug with a ground?
Would I have to replace the 20-year-old 3-prong receptacle?
Just technically speaking, could the ground prong on the male plug be cut
off to fit the old outlet (similar to what people of done for years on
110-volt stuff). Or is the wiring for 4-wire 220 volt completely
different because of 2 hot wires, neutral, ground, etc.?

The NEC allows you to use an existing three wire electric dryer feed and
receptacle. Typically, dryers don't come with cord sets, so you specify the
one you need for your outlet. Any new installations require a four wire
feeder and receptacle. If, you do have a four wire feeder, it would be
sensible to install a four wire outlet on it, then get the appropriate cord
set with the new dryer

220 volt 3-wire vs. 4-wire
 

Dryers don't come with cords. Just use your old cord on the new dryer and
go. You'll have to be sure the grounding jumper is in place on the new
dryer like it is on your old one.

s


"M.Burns" wrote in message
...
I have a 220-volt electric dryer with 3-prong plug going into a 3-prong
receptaclet (2 blades on a 'V', and third L-shaped prong).
Do newer electric dryers have a 4-wire plug with a ground?
Would I have to replace the 20-year-old 3-prong receptacle?
Just technically speaking, could the ground prong on the male plug be cut
off to fit the old outlet (similar to what people of done for years on
110-volt stuff). Or is the wiring for 4-wire 220 volt completely
different because of 2 hot wires, neutral, ground, etc.?

220 volt 3-wire vs. 4-wire
 

Canadians reading this should note differences that in Canada, dryers and
non-built in stoves have all come with 4 prong cords for the past 35 years.
Code requires receptacles that are fed by what is labeled a "3 wire plus
ground" cable. It is not Code compliant to connect the neutral and ground
together in the appliance.

"S. Barker" wrote in message
...
Dryers don't come with cords. Just use your old cord on the new dryer and
go. You'll have to be sure the grounding jumper is in place on the new
dryer like it is on your old one.

s


"M.Burns" wrote in message
...
I have a 220-volt electric dryer with 3-prong plug going into a 3-prong
receptaclet (2 blades on a 'V', and third L-shaped prong).
Do newer electric dryers have a 4-wire plug with a ground?
Would I have to replace the 20-year-old 3-prong receptacle?
Just technically speaking, could the ground prong on the male plug be cut
off to fit the old outlet (similar to what people of done for years on
110-volt stuff). Or is the wiring for 4-wire 220 volt completely
different because of 2 hot wires, neutral, ground, etc.?

220 volt 3-wire vs. 4-wire
 

On May 11, 12:08�pm, "EXT" wrote:
Canadians reading this should note differences that in Canada, dryers and
non-built in stoves have all come with 4 prong cords for the past 35 years..
Code requires receptacles that are fed by what is labeled a "3 wire plus
ground" cable. It is not Code compliant to connect the neutral and ground
together in the appliance.

"S. Barker" wrote in message

...



Dryers don't come with cords. �Just use your old cord on the new dryer and
go. �You'll have to be sure the grounding jumper is in place on the new
dryer like it is on your old one.

s

"M.Burns" wrote in message
...
I have a 220-volt electric dryer with 3-prong plug going into a 3-prong
receptaclet (2 blades on a 'V', and third L-shaped prong).
Do newer electric dryers have a 4-wire plug with a ground?
Would I have to replace the 20-year-old 3-prong receptacle?
Just technically speaking, could the ground prong on the male plug be cut
off to fit the old outlet (similar to what people of done for years on
110-volt stuff). Or is the wiring for 4-wire 220 volt �completely
different because of 2 hot wires, neutral, ground, etc.?- Hide quoted text -

- Show quoted text -

I will add that i think 3 wire is a bad idea, with a bad day it could
be a real hazard....

buy a new dryer? then get a new cord and updated outlet

220 volt 3-wire vs. 4-wire
 

- Show quoted text -

I will add that i think 3 wire is a bad idea, with a bad day it could
be a real hazard....

buy a new dryer? then get a new cord and updated outlet

Problem is - Many older houses are not wired for the updated outlet.
If you don't have the proper wiring at the outlet (2 hots - Neutral
-Ground), you are not allowed to install the 4 wire code-compliant
outlet (vs. the old 3 wire outlet). Hence the grandfather clause...

For many older houses - installing new dryer wiring would be difficult
(expensive) and involve pulling new wires and possibly ripping up
walls.

The NEC allowed the 3 wire exception to save on copper during WWII.
Then, one or two people got electrocuted by their dryers and they
decided to go back to 4 wire some years ago.

Apparently Canada never did this. Anyone know for sure?

220 volt 3-wire vs. 4-wire
 

On May 11, 2:05�pm, (Beachcomber) wrote:
- Show quoted text -

I will add that i think 3 wire is a bad idea, with a bad day it could
be a real hazard....

buy a new dryer? then get a new cord and updated outlet

Problem is - �Many older houses are not wired for the updated outlet.
If you don't have the proper wiring at the outlet (2 hots - Neutral
-Ground), you are not allowed to install the 4 wire code-compliant
outlet (vs. the old 3 wire outlet). �Hence the grandfather clause....

For many older houses - installing new dryer wiring would be difficult
(expensive) and involve pulling new wires and possibly ripping up
walls.

The NEC allowed the 3 wire exception to save on copper during WWII.
Then, one or two people got electrocuted by their dryers and they
decided to go back to 4 wire some years ago.

� Apparently Canada never did this. �Anyone know for sure?

for safety its likely worth the effort.

just look at all the other updates required today, GFCI, arc fault,
getting rid of K&T to obtain insurance, replacing fuse boxes, etc etc.

wonder why the dryer exception has survived?

220 volt 3-wire vs. 4-wire
 

On Sun, 11 May 2008 17:48:32 -0400, wrote:

On Sun, 11 May 2008 14:38:50 -0700 (PDT), "
wrote:

wonder why the dryer exception has survived?

Not much of a body count to justify changing it.

Beautifully put. :D

220 volt 3-wire vs. 4-wire
 

wrote in message
...
for safety its likely worth the effort.

just look at all the other updates required today, GFCI, arc fault,
getting rid of K&T to obtain insurance, replacing fuse boxes, etc etc.

wonder why the dryer exception has survived?

While it is a good idea, houses and people survived for many years without
all the safety equipment.

220 volt 3-wire vs. 4-wire
 

if the grounding jumper is properly in place, then it's just as safe as a 4
wire. IF in fact anyone was actually shocked by a dryer, then it was a
dufus installation problem, not a # of wires problem.

steve


wrote in message
...
On May 11, 2:05?pm, (Beachcomber) wrote:
- Show quoted text -

I will add that i think 3 wire is a bad idea, with a bad day it could
be a real hazard....

buy a new dryer? then get a new cord and updated outlet

Problem is - ?Many older houses are not wired for the updated outlet.
If you don't have the proper wiring at the outlet (2 hots - Neutral
-Ground), you are not allowed to install the 4 wire code-compliant
outlet (vs. the old 3 wire outlet). ?Hence the grandfather clause...

For many older houses - installing new dryer wiring would be difficult
(expensive) and involve pulling new wires and possibly ripping up
walls.

The NEC allowed the 3 wire exception to save on copper during WWII.
Then, one or two people got electrocuted by their dryers and they
decided to go back to 4 wire some years ago.

? Apparently Canada never did this. ?Anyone know for sure?

for safety its likely worth the effort.

just look at all the other updates required today, GFCI, arc fault,
getting rid of K&T to obtain insurance, replacing fuse boxes, etc etc.

wonder why the dryer exception has survived?

220 volt 3-wire vs. 4-wire
 

On Sun, 11 May 2008 18:16:08 -0500, "S. Barker"
wrote:

if the grounding jumper is properly in place, then it's just as safe as a 4
wire. IF in fact anyone was actually shocked by a dryer, then it was a
dufus installation problem, not a # of wires problem.


Safe is a relative term. The safest installation would be to have
the neutral separate from the grounded frame of the dryer, especially
since in the US, dryers have 120 V. motors and thus there is always
neutral current flowing when the appliance is operating.

The exception was apparently allowed because it is extremely rare for
the neutral to become disconnected, which could potentially energize
the frame of the dryer to 120 V. Most dryers are installed next to a
washing maching, which is more-than-likely to be properly grounded.
Thus you would have a possible shock hazard.

But, as mentioned before, most owners of older homes are not going to
want to spend the money to rewire the dryer circuit for something that
has basically worked fine for 10-40 years, if the 3-wire dryer plug
option is allowed.

220 volt 3-wire vs. 4-wire
 

if the grounding jumper is properly in place, then it's just as safe as a 4
wire.


This is NOT true.

The three wire system, even when properly installed to code is
dangerous becasue an OPEN circuit (which can happen) in the 3rd ground/
neutral wire) can end up energizing the metal chassis of the dryer
through the 120 volt clock motor or other 120 volt parts in the
dryer. If someone then touches say the properly grounded washing
machine and the dryer at the same time, they could get a dangerous
shock.

That being said, I have a three wire install in my house and it can be
made safe with the simple addition of an axtra ground wire connected
from the case of the dreyer to a good ground such as a nearby water
pipe. I have a ground wire connected between the dreyer and the
washer, therefore there can be no voltage across them.

Yes three wire system were code and can be grandfathered to code, but
they can still be dangerous and I would add the extra ground wire to
be safe. Rewiring for a full 4 prong plug can be expensive if a new
cable has to be pulled. Adding an external ground wire is cheap and
easy and effective.

Mark