One for the old timers; Bare neutral?

hillbilly1

Senior Member
Location
Atlanta,Ga
Occupation
Field coordinator/ technical support
Might depend on how tightly designed the motor is to the load, if not loaded too heavily many 240 volt designed motors can run @ 208.

Another possibility might be they once used same 120 volt motor on both gas and electric dryer of same product line.
True, that would reduce inventory costs too.
 

Mr. Serious

Member
Location
Oklahoma, USA
Occupation
Electrical Contractor
That 1996 code may seem recent, but it is starting to get close to being midway between now and that WWII time period.

I'm getting old! I started out as an apprentice in 1999, and we used the 1996 NEC. I only worked for three months, during which time we worked on multiple residential rough-ins, a couple of service calls, and only one residential finish job that had been roughed in before I started. After that I got fired for working too slow, and I figured being an electrician was not for me, so I did other things until 2014. So, for me, it's only been a few years since we were on the 1996 Code!
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
Which SEU does not have.
Yes, but service entrance cable specifically uses the 'bare' (actually covered by the outer sheath) as a neutral, whereas in NM the 'bare' is intended as an EGC.

The bare wire in SEU cable was specifically permitted for the grounded circuit conductor, but not the bare wire in NM. Dunno why this distinction was made.

-Jon
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Did someone ask a history question?
Let me dust off the collection...

Prior to the 1940 code grounding of a range with a grounded conductor was done by 'special permission' as implied by 2259(c).
The 1937 NEC handbook discusses this:
1937_ranges.png

Section 2560 Was first added to the 1947 Code it stated frames of electric ranges may be grounded to the grounded circuit conductor.

The 1953 NEC Expanded to electric dryers and added the requirement to 2560 that the conductor be at least 10AWG and the range be 120-240 three wire circuits.

The 1965 NEC 250-60 was the last code that allowed a frame of a single phase range or dryer to be grounded by the 'grounded circuit conductor' on the single condition that the wire was 10AWG or larger.

The 1968 NEC added that the grounded conductor of an SE cable could be used and the branch circuit had to originate at a service.
The 1996 code changes 250-60 to 'existing installations only' and the wording is much the same today.

The NEC consistently required conductors to be insulated the only exception I see is the standard one which allowed an equipment grounding conductor to be bare as is allowed today.
So to conclude the visit to the old books I think it would have been only by 'special permission' that the bare of a 10/2 could be used to ground a range or dryer legally.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Did someone ask a history question?
Let me dust off the collection...

Prior to the 1940 code grounding of a range with a grounded conductor was done by 'special permission' as implied by 2259(c).
The 1937 NEC handbook discusses this:
View attachment 2557884

Section 2560 Was first added to the 1947 Code it stated frames of electric ranges may be grounded to the grounded circuit conductor.

The 1953 NEC Expanded to electric dryers and added the requirement to 2560 that the conductor be at least 10AWG and the range be 120-240 three wire circuits.

The 1965 NEC 250-60 was the last code that allowed a frame of a single phase range or dryer to be grounded by the 'grounded circuit conductor' on the single condition that the wire was 10AWG or larger.

The 1968 NEC added that the grounded conductor of an SE cable could be used and the branch circuit had to originate at a service.
The 1996 code changes 250-60 to 'existing installations only' and the wording is much the same today.

The NEC consistently required conductors to be insulated the only exception I see is the standard one which allowed an equipment grounding conductor to be bare as is allowed today.
So to conclude the visit to the old books I think it would have been only by 'special permission' that the bare of a 10/2 could be used to ground a range or dryer legally.
Those old Code books come in handy. Thanks for doing the research.
 

kwired

Electron manager
Location
NE Nebraska
Never seen straight 240v range or dryer, based on the fact that I've always seen a white hooked to neutral on terminal block
I have seen ranges that had no neutral loads within but still had the three wire power terminal strip with a factory installed strap to the frame in the center position. No load neutral wires within the appliance though. I don't see why one couldn't have used a three wire cord with a 6-50 cap on it on that one. I had like 30 of them to install one time for low income housing facility. Only 24 inch wide ranges, four surface elements and oven, no clock, no oven light, nothing 120 volt on the appliance. These were replacing existing gas ranges, so I was also installing supply circuit and receptacle. I went with the typical 14-50 simply because who knows what they may be replaced with someday that might need a neutral.
 
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