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Do any of you remember what years the flowing NMD cables were introduced??

NMD-3 Cloth Jacket
NMD-7 Cloth Jacket
NMD-7 PVC Jacket
NMD-90 PVC Jacket

The town I live in was flooded in 1963, so all the house are from this date onward. I see all these types of cable & I am trying to find out what year each cable type came out in order to see what time period the wire would have been installed. I have been doing this since the late 80's & I never installed any of the cloth type NMD-7, but I don't remember the exact year that NMD-90 came out either.

Also, have any of you ever asked an inspector if a building/house you were working on had previous permits pulled?? If so, were they able to tell you if permits were pulled or was it confidential??
 

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RIP 1959-2015
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Do any of you remember what years the flowing NMD cables were introduced??

NMD-3 Cloth Jacket
NMD-7 Cloth Jacket
NMD-7 PVC Jacket
NMD-90 PVC Jacket

The town I live in was flooded in 1963, so all the house are from this date onward. I see all these types of cable & I am trying to find out what year each cable type came out in order to see what time period the wire would have been installed. I have been doing this since the late 80's & I never installed any of the cloth type NMD-7, but I don't remember the exact year that NMD-90 came out either.

Also, have any of you ever asked an inspector if a building/house you were working on had previous permits pulled?? If so, were they able to tell you if permits were pulled or was it confidential??
The cloth NM cable went out around 1964.
 

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RIP 1959-2015
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39,618 Posts
Fig. 3 – Early Catalog D
e
scription of Armored C
abl
e
Nonmetallic Cable
Althoug
h nonmetallic-
s
heathed cable, or
NM for short, was first listed and
described in the NEC in 1926, it was ac
tually invented a few years earlier by
General Cable at their Rome Wire Div
ision in Rome, NY, and marketed under the
trade name “Romex
®
.” Today many installer
s
still refer generica
lly to NM cable
as Romex. Early NM cable had their
indiv
i
dual conduct
o
rs jacket wrapped in a
cotton braid that was impregnated with either
a varnish or tar-like substance for
moisture protection.
Around 1950, synthetic spun rayon was
being permitted to replace the cotton
thread in the jacket braid. Then in
the early 1960’s, thermoplastic began
replacing the braided jacke
t altogether, and by about 1970,
most all NM cable
had a PVC outer jacket, even though a braid
was still permitted until 1984. Also
in 1984, NM-B cable was developed and r
equired to have 90°C rated indiv
i
dual
conductors, and a 75°C outer jacket (see Fig. 4).
Until the early 1960’s, most NM cabl
e for residential use did not have a
grounding conductor. However, c
hanges in the 1962 Code that mandated
equipment grounding for all branch circuits
populariz
ed the use of NM cable with
ground. Earlier versions of NM c
able with ground permitted the grounding
conductor to be No. 16 AWG for 14 and
12 gauge copper NM, and No. 14 AWG
ground for 10 gauge c
opper NM. In 1969,
new requirements no longer permitted
an undersized grounding conduct
o
r for
14, 12 and 10 gauge NM cable.
 

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This thread should be moved to the Canadian section, since NMD is unique to the great white north ....

Edit to add: Looks like it has been moved.

NMD generally has a grounding conductor that is smaller than the circuit conductors are. As such, it would never be permitted to be used in the US ...
 
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