Oh No! Another Electrical Question

I recently purchased a house for rental use.

The dryer receptacle is the 3 prong style.

If the tenant's dryer has a newer 4 prong cord set, should I change the receptacle, or offer to change the dryer cord?

If I change the receptacle, is there an acceptable way to wire it to the existing 3 conductor wire?

And if I change the cord, would the ground and neutral then be tied together inside the dryer?

Thanks!

The correct answer is to hire me so I can escape the cold in nebraska and go to Texas ( I think that's where you are at).
Really then, no way to make a 3 wire into a 4 wire, legally any ways. Put a new 3 wire cord on and make sure the frame of the dryer is bonded to the neutral wire. They all come from the factory with the strap for bonding but they sometimes get pitched when someone puts on a 4 wire cord.

That one is a catch 22 as in at one time the 3 wires was up to code but now days it in not. So to be legal and up to code you need to have a 4th wire run and a 4 prone plug installed. Yes you can put a 3 wire plug on the newer dryer but it is not up to code as of right now

my rentals have the 3 prong receptacles. i have the appliance company install the 3 prong cord when replacing the dryers. have the tenant or an appliance guy do it, dont do it yourself, if there is a problem, you will get blamed!!

Steve, there are instructions on the back of the dryer. All new dryers come with a bar connecting neutral to ground. The instructions say to remove bar for 4 wire.

It also says if dryer is used in a mobile home it has to be 4 wire.

NEC requires all new construction after a certain date to be 4 wire.

I installed a new dryer in my old house. Posted pic of the instructions on back of dryer and the code police on YT blew a fuse.

Some electricians say there is an exemption for old construction and 3 wire is OK. Some on YT think that people like me that can read instructions and are not licensed electricians shouldn't hand out advice.

BTW, as a landlord, tell the tenant to change the cord may be the best advice if you aren't an electrician. It Prevents you from getting sued.

Same advice when it comes to pest control. I won't spray any chemicals. A tenant could claim what you put down made their kid or dog sick, then right or wrong, you have to defend your self in court.

I googled looking for anyone has been electrocuted because of 3 wire, couldn't find one article. Wish someone could post a link to an electrocution linked to 3 wire.
geo

(quoted from post at 16:29:27 12/23/16) my rentals have the 3 prong receptacles. i have the appliance company install the 3 prong cord when replacing the dryers. have the tenant or an appliance guy do it, dont do it yourself, if there is a problem, you will get blamed!!

Click to expand...

hat is correct. The appliance deliverer/installer will have both 3 & 4 prong cables & will use as need to match your receptacle.

Dec. 2013 we moved our son from a rental house in Mooresville NC to a newly refurbished, not very old house he purchased nearby. I was so surprised to find the newly refurbished house had a three prong dryer outlet. His dryer had a four prong cord. We went to Lowes and got a three prong cord. Dryer showed connections for both. What surprised me was that this house should have been thoroughly inspected. This past Thanksgiving I was helping him check out the wiring/circuits/outlets over the kitchen counter in anticipation of some splash board tiling he wanted to do. All 14 ga. wire on 20 amp circuits!

We bought a brand new dryer about 2 years ago. The installers removed the cord from the old dryer, installed it on the new dryer, and plugged it into the same 3 prong plug that I installed 20 years ago. There was NO indication that the new dryer needed a 4 prong plug.

So many people have no problem connecting the chassis of a dryer that they touch in a damp laundry room to a load current carrying electrical conductor ???
Any real grounds in the house ? Metal Water pipe, metal gas pipe, well casing, ground rods etc ?

As mentioned, I would not do it if I were you, I would have them hire someone to do it. Keep the liability off of you.....

But, yes, that is how electric driers are, 3 or 4 wire cord and one of the few (only?) times such a bonding is allowed any more in certain conditions.

Paul

So what is the fourth wire? 2 hots, a neutral and an earth ground for the fourth?

You got it

Old, A few years ago, I posted a pic of instructions on the back of a new dryer it created a fire storm. Someone pointed out there is an exemption for older homes, 3 wire. NEC 4 wire is only code for new construction, which includes room additions. I made a master bedroom with a bath/laundry. I had to get a building permit for the addition. Building inspector checked every thing during construction and a final inspection after. I was required to use 4 wire on new part of the house. I wasn't required to upgrade to a 4 wire.

My boy sold a house built in the 70's and he didn't have to bring his range and dryer up to new NEC code.

Not sure about trailers. On new dryer's instruction, it said mobile homes need 4 wire. Not sure if mobile homes were always 4 wire or if older ones are exempt too.
geo.

Steve, yours is a good question and you likely understand all this, but I have tried for over 15 years to explain to non electricians and non engineers the DIFFERENCE between the GrounDED Conductor (Neutral) and the Safety Equipment GroundING Conductor BUT THEY JUST DONT SEEM TO GET IT and pooh pooh and make fun of the National Electrical Codes board of electrical experts and know more then they do, so I give up and tell them to do as they please lol

The Grounded Conductor (Neutral) is a live current carrying conductor intended for carrying normal return current

The Safety Equipment GroundING Conductor is designed to carry ONLY fault current by providing a dedicated low impedance fault current return path to trip the breaker and save your life IT DOES NOTTTTTTTTTTTTT CARRY NORMAL RETURN CURRENT only fault current.

The Neutral IS INSULATED for safety reasons while the safety equipment grounding conductor is often bonded to the outer metal case frame of tools or appliances. Would you strip the insulation off the Neutral and tell your grandchild to touch it ASK YOURSELF THAT ???????? If you bond the Neutral to the outer metal dryer frame and your barefoot grandchild comes in on a wet floor and touches it and got electrocuted you would give your life to have done it right !!!!!!!!!!!! YES Billy Bob and Bubba that can happen

If you come in contact with a live current carrying Neutral (because its wired to say the dryers metal frame) YOU ARE POSSIBLY PLACING YOUR BODY IN PARALEL WITH LIVE CURRENT AND SOME CURRENT CAN FLOW THROUGH YOUR BODY AND HEART AND YOU CAN DIE IF ITS IN THE 30 TO 50 MA AND OVER RANGE

SO TO ANSWER YOUR QUESTIONS

1) If the tenant's dryer has a newer 4 prong cord set, should I change the receptacle, or offer to change the dryer cord?

I WOULD CHANGE OUT THE RECEPTACLE that the safest thing to do plus it takes it up to modern code and may save a life plus may keep you from being sued ITS YOUR CHOICE

2) If I change the receptacle, is there an acceptable way to wire it to the existing 3 conductor wire?

NOT a good correct way in my opinion even though sure Billy Bob and Bubba it can work

3) And if I change the cord, would the ground and neutral then be tied together inside the dryer?

It may well be I cant say from here


BOTTOM LINE its your risk of liability and a risk of a life so do as you please but as I see it your choices are:

(A) Listen to non electricians, non professionals, non engineers and do what they say !!!!!!!!!!!!!!

(B) Do as the National Electrical Code and professional electricians and professional electrical engineers advise

DO NOT DO AS I SAY DONT TAKE MY WORD FOR IT IM TOO LONG RETIRED FORM ELECTRICAL ENGINEERING PRACTICE AND RUSTY ON THE LATEST CODES (but if I were the responsible design engineer and was providing service for a modern 4 wire dryer Id use a matching modern 4 wire receptacle)

I WOULD NEVERRRRRRRRR WANT TO TOUCH A LIVE CURRENT CARRYING CONDUCTOR AND PLACE MY BODY IN PARALELL WITH IT SO IT CAN CARRY A SHARE OF THE CURRENT (can happen if Neutral is bonded to dryer frame) BUT IF BILLY BOB AND BUBBA WANT TO FINE LOL They know more then the NEC experts, just ask them !!!!!!!!!!!!

DO AS YALL PLEASE IS FINE BY ME

John T BSEE, JD retired

Now that I think about it (after reading John T's post), we bought a new stove about five years ago and put a three wire cord on it. If you touch the wrong part of the stove and the microwave at the same time you can get a bite. I bet it needs to go to a four wire receptacle with upgraded wiring. This house was done by an electrician but I've found wayyyyy too many dead-end wire nuts hanging in wall cavities to trust that receptacle.

My 1982 mobile home is a 3 wire set up as is all the building I have But I also have ground rods at each and every breaker box that is in the buildings so as to make sure I have a good ground every place. Plus most of my building are metal frame so each of them is grounded extra well due th pipes etc being in the ground and some as deep as 4 foot.

I've got to meet john t someday

Just so people understand, just because an appliance is 3 wire that's not necessarily a problem, its if the Neutral is bonded to the outer case/frame such as mixing and matching Neutrals and Grounds the wrong way it can become hazardous. Some older appliances were 120 and 240 and that's where problems arose if you only ran 3 wires to it. If it was 240 only no problem with 3 wires, 2 hots and a ground, no Neutral required.

John T

Thanks for all the replies. I don't have a tenant yet, just wanted to be ready if the situation arises.

Best I understand, the 3 conductor is grandfathered, so still legal though not the best.

Sounds like best to leave it up to the tenant as to what they want to do, and let them hire it done.

Greg, come on down! Supposed to be 72* Christmas day.

That's my kinda weather!

Just keep in mind if someone's kid got fried you would be the first person they would be pointing a finger at.

Old,
I went to college in the 60's. Back then all mobile homes were wired with four wire. Mobile homes came from factory with a 60 amp 4 wire extension cord. So the 4 wire code existed way back then. Not sure about clothes dryers and ranges. Most trailers didn't come from factory with electric ranges or dryers. Ranges were all gas so they could get by with 60 amp service.
geo.

I have seen that in large travel trailers but not on a true mobile home. My 1956 8X45 mobile home still had a true fuse box and this one I have now is a 3 wire set up.