I've noticed a bit of confusion lately with new requirements for 4 wire dryer circuits.

#1 a Store employee told a customer that was looking for a dryer outlet that He had to install a 4 wire receptacle (& cord/plug) even though He only had a 3 wire cable there now. - "Just put a Jumper" (I made a point to correct him)

#2 I've had the task of installing several 4 wire dryers recently and noticed that the labels on the Appliances give instructions on where to connect the 4 wires (including ground) but do not inform you that the Factory-Installed bond from neutral to frame has to be severed. Only after digging into the manual did I find a Fuzzy description of what had to be done. (Bad picture too!)

Has anyone else noticed this?

A lot of sparky's are getting into it with appliance peddlers, most of whom are not versed in the NEC,yet may suggest, or even install. I find a lot of outdated reference to the old 250-60.
In trying to explain the need for a 4-prong pigtail, i've been simply pointing out an average receptacle's separation of N & G, as relates to recent code practice concerning dryers, ranges etc.
One has to have a shred of sympathy for the appliance man here, who has been pedaling 3-prongs forever.

I once read an article explaining why the three wire dryer circuit was permitted in the first place. I believe the reason given was shortage of copper. Did anyone else ever hear such a reason?

(Frank) cinkerf

I would imagine any metal was "rationed" during WW2.....

Until the 50's, equipment grounding was not considered a big deal. Washing machine outlets had 2 wire receptacles. Machines came with a jumper and clamp to connect to the cold water pipe. Electric dryers were treated the same. The problems developed when the appliances were on a concrete floor, and the jumper was not connected. To avoid lawsuits, the manufacturers grounded the neutral to the frame. Many are still in operation. It will be a long time before homes catch up with the four wire connections.
I don't think material shortage had anything to do with the three wire circuit, it was just the thinking at the time, face it, they work, and don't appear to be a problem, other than the discomfort of the customer, when the plug won't fit.
My personal opinion is; There was nothing dangerous with the three wire connection, and it should have been left alone.

Bennie,
Thank you for clarification.
(Frank) cinkerf

Okay... Im confused...

Wouldn't bonding the frame of a clothes dryer to the neutral on a three-wire be similar to bonding the Green Screw of a 125V receptacle to the neutral on an old two-wire circuit to achieve a "grounded" plug?

I don't see the difference especially considering that most, if not all dryer motors run on 120V, unbalancing the loads a significant amount. So either I'm missing something here...or...?

I've been known to insist upon four-wire installations if I have my name associated with it, am I justified in this thinking? Or have I been "just hard to get along with"?

Thanks for your comments, and don't be afraid to correct me! I'm always learning...

Good question -

I'm also interested in hearing the reason why a 3 conductor SE cable (2 insulated 1 bare) was allowed for a 3 wire Dryer installation and not a 10/2 Romex w/gr

Bill

I heard exactly the same rumor about the copper shortage in WW2 & I believe that is the reason that the 3 wire installation was allowed. As a side note, the Manhattan Project would have used so much copper for transformers that it would have actually hurt the war effort. The treasury ponied up several million ounces of silver which was made into wire for the required transformers.

As Bennie pointed out, the 3 wire installation has had an excellant safety record. However, the jacklegs in this business started to think that neutrals (wahatever they are) and equipment grounds were interchangeable. I think it is best that we have now gone to a 4 wire installation.

Tom

My concern regarding the change, is it is too little too late. There is many more older homes than new ones. Homes far outlast the appliance.
Homeowners will often change the attachment cord to a three wire, now there is no ground at all. Should they change the receptacle to a four wire, they do not have the fourth wire, again, no ground at all. This is not increasing safety. Very bad decision, in my opinion. It was not broke until the fix was in.

Bennie,

I have no problem adherring to this 4 wire rule for New Installations. My comments were regarding the training of the Salesperson and the surprising lack of documentation on the Appliance itself. I thought they usually covered themselves pretty good that way. Look at the Anti-tip (don't step on the door of the Range) pictures - I get a kick out of that one!

Labels on the outside (2) described how the 4th wire was to connect to the Green screw on the Frame but did not mention at all that the neutral-to-frame bond was then supposed to be cut. The connection (a butt splice) was located behind the connecting block and not visible. I knew that it was there somewhere, but I wonder how many never get cut?

Since there has not been any problems up to now, with grounding the dryer with the neutral, why is there concern about the neutral to ground link on dryers on a 4-wire system? If it is there, the paths have not changed, tho paralleled, which could be a problem. If it is removed, the paths are still there, but now on the correct wires.

My thought would be to get the manufacturers to build these units without the link, giving the homeowner/electrician the option to install it, if installed on a 3-wire system, which, with each new home built or new dryer circuit installed, is decreasing in use. The installation instructions need to concise and understandable.

This is the same as giving the homeowner/electrician the option to remove it for a 4-wire system, as is currently the situation.

Rick Miell

Isn't a dryer really a 120/240 deal? aren't there some 120v cotrols, indicator lights etc.
Can't we talk fundamental electrical theory here?

Sparky,

Yes, the Dryer is a 120/240v Appliance. The Heating elements are 240v and everything else is 120v. Normally this would require a 4 wire circuit, but the NEC had allowed 3 wire cables (for Ranges also) for many years under certain conditions. The most common wiring I've seen is SE cable. The following is a Quote from 1990 Handbook (notes after 250-60)

The use of the grounded circuit conductor for grounding purposes is contrary to other requirements of the Code..... However, it has been allowed for many years because of the good safety record of these particular appliances that are grounded through the grounded circuit conductor and because an open splice or break in the grounded circuit conductor would normally render the appliance inoperable.....

Rick, I'm not really that concerned (safetywise) about the link not being removed, I just find it Ironic at best, that the code rules are changed and 4 wire receptacles are installed but many dryers will still be "3 wire" because nobody knows how to cut the link.

The agreement by manufacturers, when the four wire concept was adopted, was that the dryers would not be sold with an attachment cord. The neutral/ground link was to be present, but not connected.
The customer could install a cord to match the existing receptacle. This was the manufacturers decision to limit liability, and to not discourage sales. Both the three or four wire cords could be installed.
Some of the more reputable dealers have a service person install the dryer, and connect vent, and cord. There is some that don't, it is up to the buyer.
There will soon be a washing machine, approved for ungrounded operation. I expect to see a dryer, soon.
Manufacturers are getting hammered with product liability lawsuits, from persons being injured by appliances that have grounding cords, and the circuit does not have an equipment ground wire. This is regarded as a false implication of safety. The manufacturers lose all cases, they are usually settled out of court.
Grounding of appliances has been out of phase with the code book, since day one.
Count the metal appliances, in your kitchen, that have a three wire cord. Count the appliances, in your home, that have a three wire cord. Count the outlets that have a three wire receptacle that will never see a three wire cord.

Bennie,

How can you have a "Link" that is not connected? I don't understand what you mean by this. Can you please explain a little more?

The instructions state; For three wire cords connect the link, to the neutral terminal. Four wire cords, do not connect the link.
This is only one name brand manufacturers instructions. I have seen homeowners connect the neutral and ground to the same terminal and not connect the link. I have seen some with the ground to the frame, and the link connected. I have seen many with a three wire cords and the link not connected. This change is really creating problems with persons that often move to other homes.