Proper receptacle for Dryer

[hardworkingstiff]

That is why it is prohibited in a manufactured home.

Wouldn't that also be the reason it (branch circuit) is required to originate in the service panel in order to use the exception?

 

[kwired]

That is why it is prohibited in a manufactured home.

Same thing can happen anywhere else, I don't think it is the only reason why not allowed in a manufactured or mobile home.

 

[jxofaltrds]

Same thing can happen anywhere else, I don't think it is the only reason why not allowed in a manufactured or mobile home.

In a manufactured home (mobile is not PC now ) you bond the frame. they do not want the frame energized.

 

[jxofaltrds]

In a manufactured home (mobile is not PC now ) you bond the frame. they do not want the frame energized.

PS on a double make sure to bond the two sides together. That wire is located at one end and is often missed.

http://omhc.ohio.gov/Video.aspx
click on chapter 20

 

[JDBrown]

Well, after all the additional information that's come out, I must admit to being a little baffled. What's the issue here? There's an existing 3-wire dryer receptacle. The dryer Manufacturer's instructions show how to connect it using a 3-wire cord. Install a 3-wire cord per the Manufacturer's instructions, plug it in, and you're done. NEC doesn't care how the dryer is wired internally -- that's an issue for UL (and it apparently passed UL's testing).

Now, it might not be a bad idea for the OP to point out to the owner that the existing receptacle is not code-compliant, and see if he's willing to pay for an upgrade (if for no other reason, just to cover himself liability-wise). But the Electrician certainly isn't responsible for bringing an existing condition he didn't touch into compliance with current code.

 

[jxofaltrds]

Well, after all the additional information that's come out, I must admit to being a little baffled. What's the issue here? There's an existing 3-wire dryer receptacle. The dryer Manufacturer's instructions show how to connect it using a 3-wire cord. Install a 3-wire cord per the Manufacturer's instructions, plug it in, and you're done. NEC doesn't care how the dryer is wired internally -- that's an issue for UL (and it apparently passed UL's testing).

Now, it might not be a bad idea for the OP to point out to the owner that the existing receptacle is not code-compliant, and see if he's willing to pay for an upgrade (if for no other reason, just to cover himself liability-wise). But the Electrician certainly isn't responsible for bringing an existing condition he didn't touch into compliance with current code.

The existing receptacle IS code compliant.

 

[JDBrown]

The existing receptacle IS code compliant.

It is? Then what was all that talk about it not being allowed because it's not connected to the service panel? Or was that a side discussion that didn't deal with the OP's situation?

 

[jxofaltrds]

OP is an existing application.

IMHO the original installation may have considered this:

Service Equipment. The necessary equipment, usually consisting
of a circuit breaker(s) or switch(es) and fuse(s) and
their accessories, connected to the load end of service conductors
to a building or other structure, or an otherwise designated
area, and intended to constitute the main control and cutoff of
the supply.

Bet this is a condo or an apt.

It is? Then what was all that talk about it not being allowed because it's not connected to the service panel? Or was that a side discussion that didn't deal with the OP's situation?

I say that it meets the service equipment definition. If you go back I have always said that the OP should wire per the instructions.

I'm guessing a disconnect outside and the unit's main panel inside. So I say that it is OK. Plus it was approved at one time and that makes it compliant as long as no one starts moving wires around. For me to not allow this would require a safety hazard and from what I have read that is not the case.

 

[mbrooke]

Seems I have been disagreeing with you a lot lately, but I do agree with you here:blink:

This appliance is apparently intended to be connected to a 125/250 volt supply even though there is no neutral conductor necessary for operation. I have seen some ranges that are US design, that do not utilize a neutral, but still have same 3/4 wire 125/250 volt supply arrangements as most other ranges. I did about 30 apartments a few years back with all of them being that way, since they were new branch circuits they all had 14-50 configuration cords and receptacle installed and the neutral did nothing. But the neutral was still there if they ever changed to a range that needed a neutral. If I were OP I would connect the 10-30 plug and install the bonding jumper in the appliance, if not comfortable with that for some reason then install a 4 wire circuit and a 14-30 receptacle.

I think the instructions are just generics, I looked at others from American appliances and it just looks like a cut and paste.

My concern is all this originates from the sub panel. I wouldn't worry from a main service. Grounding through the neutral would cause 1 or 2 major appliances to be at a different potential to ground. It could also easily break the neutral ground separation down stream of the main panel.

 

[mbrooke]

If I understand the OP correctly, the branch circuit originates from a sub panel and not the service equipment. If that is the case, I don't see how the exception listed above can be used to let the circuit stand as is. This is from a technical perspective.

Personally, I don't see it as a big deal, but that is just my opinion and doesn't count.

I do know that I recently relocated some switches in a commercial building and I used mc cable. I pulled 3-wire cable so a neutral would be in the switch box, and I asked the inspector if the job would have been turned down if I had used a 2-wire cable instead of the 3-wire. The answer was .

The circuit does originate from a sub panel. Laundry is on the second floor and the sub is in the attached garage hence why it is such a challenge to pull up a new home run.


From the wording of the code it is my understanding that as long as the neutral is insulated it this can originate from a sub panel. At least that's my interpretation. Of note my older code book has a semi colon my new one has a comma, not sure if that means something?

OP is an existing application.

IMHO the original installation may have considered this:

Service Equipment. The necessary equipment, usually consisting
of a circuit breaker(s) or switch(es) and fuse(s) and
their accessories, connected to the load end of service conductors
to a building or other structure, or an otherwise designated
area, and intended to constitute the main control and cutoff of
the supply.

Bet this is a condo or an apt.

Its is a Condo. Subpanel is fed with 1/0 AL SER, main disconnects on the exterior.

 

[hardworkingstiff]

From the wording of the code it is my understanding that as long as the neutral is insulated it this can originate from a sub panel. At least that's my interpretation.

I don't understand how you can interpret it that way. Seems like you meet all of the requirements EXCEPT the one that requires the branch circuit to originate in the service equipment.

250.140 Frames of Ranges and Clothes Dryers. Frames
of electric ranges, wall-mounted ovens, counter-mounted
cooking units, clothes dryers, and outlet or junction boxes
that are part of the circuit for these appliances shall be
connected to the equipment grounding conductor in the
manner specified by 250.134 or 250.138.
Exception: For existing branch-circuit installations only
where an equipment grounding conductor is not present in
the outlet or junction box, the frames of electric ranges,
wall-mounted ovens, counter-mounted cooking units,
clothes dryers, and outlet or junction boxes that are part of
the circuit for these appliances shall be permitted to be
connected to the grounded circuit conductor if all the following
conditions are met.
(1) The supply circuit is 120/240-volt, single-phase, 3-wire;
or 208Y/120-volt derived from a 3-phase, 4-wire, wyeconnected
system.
(2) The grounded conductor is not smaller than 10 AWG
copper or 8 AWG aluminum.
(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE serviceentrance
cable and the branch circuit originates at the
service equipment.
(4) Grounding contacts of receptacles furnished as part of
the equipment are bonded to the equipment.

 

[mbrooke]

I don't understand how you can interpret it that way. Seems like you meet all of the requirements EXCEPT the one that requires the branch circuit to originate in the service equipment.

250.140 Frames of Ranges and Clothes Dryers. Frames
of electric ranges, wall-mounted ovens, counter-mounted
cooking units, clothes dryers, and outlet or junction boxes
that are part of the circuit for these appliances shall be
connected to the equipment grounding conductor in the
manner specified by 250.134 or 250.138.
Exception: For existing branch-circuit installations only
where an equipment grounding conductor is not present in
the outlet or junction box, the frames of electric ranges,
wall-mounted ovens, counter-mounted cooking units,
clothes dryers, and outlet or junction boxes that are part of
the circuit for these appliances shall be permitted to be
connected to the grounded circuit conductor if all the following
conditions are met.
(1) The supply circuit is 120/240-volt, single-phase, 3-wire;
or 208Y/120-volt derived from a 3-phase, 4-wire, wye connected
system.
(2) The grounded conductor is not smaller than 10 AWG
copper or 8 AWG aluminum.
(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE service entrance
cable and the branch circuit originates at the
service equipment.
(4) Grounding contacts of receptacles furnished as part of
the equipment are bonded to the equipment.
250.142 Use of Grounded Circuit Conductor for
Grounding Equipment.
(A) Supply-Side Equipment. A grounded circuit conductor
shall be permitted to ground non?current-carrying metal
parts of equipment, raceways, and other enclosures at any
of the following locations:
(1) On the supply side or within the enclosure of the ac
service-disconnecting means
(2) On the supply side or within the enclosure of the main
disconnecting means for separate buildings as provided
in 250.32(B)
(3) On the supply side or within the enclosure of the main
disconnecting means or overcurrent devices of a separately
derived system where permitted by 250.30(A)(1)
(B) Load-Side Equipment. Except as permitted in
250.30(A)(1) and 250.32(B) Exception, a grounded circuit
conductor shall not be used for grounding non?
current-carrying metal parts of equipment on the load
side of the service disconnecting means or on the load



From my take "or" lists 2 different scenarios, rather than applying it 2 both conditions. I have seen many apartments and some fast food equipment with this arrangement. Every other apartment I have seen is wired like this.

The condo in particular is part of a complex with 100 units all like this. All the stoves are wired in 6/3 without ground and all the dryers 10/3 without ground. The complex passed inspection and no other violations stand out.

Im not saying your wrong, but I doubt so many apartments in the US would all have this violation.

 

[ActionDave]

..... if all the following
conditions are met....

(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE serviceentrance
cable and the branch circuit originates at the
service equipment.
(4) Grounding contacts of receptacles furnished as part of
the equipment are bonded to the equipment.

I read it the same as mbrooke

 

[JDBrown]

I read it the same as mbrooke

Serves me right for just going by others' comments. After actually reading the section, you're absolutely right. Seems this whole thread has been one big non-issue. But it's been a good learning experience (for me, anyway).

 

[hardworkingstiff]

From my take "or" lists 2 different scenarios, rather than applying it 2 both conditions. I have seen many apartments and some fast food equipment with this arrangement. Every other apartment I have seen is wired like this.

The condo in particular is part of a complex with 100 units all like this. All the stoves are wired in 6/3 without ground and all the dryers 10/3 without ground. The complex passed inspection and no other violations stand out.

Im not saying your wrong, but I doubt so many apartments in the US would all have this violation.

You made a good enough point that I dug up my 2011 handbook. The wording in the handbook seems to indicate that your posted interpretation is correct and mine is wrong. I stand corrected, and I thank you. :thumbsup:

I guess it's obvious that I've not done residential work in decades.

 

[mjf]

250.140 Frames of Ranges and Clothes Dryers. Frames
of electric ranges, wall-mounted ovens, counter-mounted
cooking units, clothes dryers, and outlet or junction boxes
that are part of the circuit for these appliances shall be
connected to the equipment grounding conductor in the
manner specified by 250.134 or 250.138.
Exception: For existing branch-circuit installations only
where an equipment grounding conductor is not present in
the outlet or junction box, the frames of electric ranges,
wall-mounted ovens, counter-mounted cooking units,
clothes dryers, and outlet or junction boxes that are part of
the circuit for these appliances shall be permitted to be
connected to the grounded circuit conductor if all the following
conditions are met.
(1) The supply circuit is 120/240-volt, single-phase, 3-wire;
or 208Y/120-volt derived from a 3-phase, 4-wire, wyeconnected
system.
(2) The grounded conductor is not smaller than 10 AWG
copper or 8 AWG aluminum.
(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE serviceentrance
cable and the branch circuit originates at the
service equipment.
(4) Grounding contacts of receptacles furnished as part of
the equipment are bonded to the equipment.

Does it technically satisfy #1 if the supply circuit is straight 240-volt and not 120/240-volt?

 

[jxofaltrds]

250.140 Frames of Ranges and Clothes Dryers. Frames
of electric ranges, wall-mounted ovens, counter-mounted
cooking units, clothes dryers, and outlet or junction boxes
that are part of the circuit for these appliances shall be
connected to the equipment grounding conductor in the
manner specified by 250.134 or 250.138.
Exception: For existing branch-circuit installations only
where an equipment grounding conductor is not present in
the outlet or junction box, the frames of electric ranges,
wall-mounted ovens, counter-mounted cooking units,
clothes dryers, and outlet or junction boxes that are part of
the circuit for these appliances shall be permitted to be
connected to the grounded circuit conductor if all the following
conditions are met.
(1) The supply circuit is 120/240-volt, single-phase, 3-wire;
or 208Y/120-volt derived from a 3-phase, 4-wire, wyeconnected
system.
(2) The grounded conductor is not smaller than 10 AWG
copper or 8 AWG aluminum.
(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE serviceentrance
cable and the branch circuit originates at the
service equipment.
(4) Grounding contacts of receptacles furnished as part of
the equipment are bonded to the equipment.

Does it technically satisfy #1 if the supply circuit is straight 240-volt and not 120/240-volt?

It is wired as a 120/240. Stop worrying about how the appliance is wired.

 

[kwired]

You made a good enough point that I dug up my 2011 handbook. The wording in the handbook seems to indicate that your posted interpretation is correct and mine is wrong. I stand corrected, and I thank you. :thumbsup:

I guess it's obvious that I've not done residential work in decades.

But these rules are not limited to residential work, and would apply to ranges or clothes dryers if there were any wherever you have been working all those years, and they do exist outside of residential applications:happyyes:

 

[hardworkingstiff]

But these rules are not limited to residential work, and would apply to ranges or clothes dryers if there were any wherever you have been working all those years, and they do exist outside of residential applications:happyyes:

No excuses, I just quit doing any resi work in 1979. I was working mostly gas stations and fluid control systems since 1980, so I never needed to use the exception we were discussing since we don't use ranges or clothes dryers in those operations. Then I moved into wiring marinas.

I've never claimed to be a code nut and usually just brush up on what I needed to know for what I was doing. I guess to most of y'all I'm not a real electrician because I am self taught and have never taken a code class until I moved to NC and needed to for continuing education credits to keep my license.

Since you are much better educated than I on the NEC, maybe you can explain why a 10/3 w/out a ground can have the appliance grounded by the neutral even if from a sub panel, but the 8/3 SEU is only allowed to be used if it originates in the service equipment? Also, If you had a separate ground and neutral bar in the service equipment, which bar would you terminate the bare wires in the 8/3 on, and why? The bare wires are feeding a 120/240 no ground receptacle.

What difference does it make that the neutral of the 10/3 is insulated and the bare wires on the 8/3 are not as far as being allowed to use a sub panel?

 

[J.P.]

I'm also interested in the answer to this one. Sometimes it seem the NEC is built to confuse.