Class 2 wiring systems with lighting power

[MasterTheNEC]

In the case of the Lutron components that I mentioned they allow the reclassification as their equipment is setup that way. The way these systems are wired that makes it quite a bit easier, especially with pendants that have 5-wire cords like Augie mentioned.

Agreed and if they permit it then have at it....However, when a manufacturer commits to producing thousands of thousands of feet of a product and it gets installed in a building with the assumption that the dimming equipment permits reclassification only to find out it does not....who eats the cost when it goes to court.

I would hope the manufacturer of the cable is not part of the case because they just produce what the customer asks for. However, if the manufacturer knows of a way to produce a product that is acceptable without additional steps from the electrician then less chance of error and costly losses for the electrical contractor, building owner and so on.

Just my thoughts on it....I am very glad it worked out for you in your situation.

 

[shortcircuit2]

Quite simple, if the assembly meets 725.136(I)(2) then no separation is needed. The general rule of (I) calls for a separation unless item (2) is met in which the separation is not required. As for the luminaire, the .25 separation will take place by the installer and by the design of the smart luminaire manufacturer. From a cable manufacturers perspective, it is compliant to the luminaire, the installer and the manufacturer of the luminaire will handle their part of compliance.

FYI- I guess I should also add, the insulation on the Class 2 or 3 conductors are also 600V rated just like the lighting and power circuit conductors.

I don't see how your interpretation of 725.136(I)(2) permits a low voltage pair of wires to be enclosed within the same cable or raceway as conductors for light and power.

I would interpret that 725.136(I) refers to "Other Applications" such as when the 2 cables cross paths in general construction areas of buildings.

 

[MasterTheNEC]

I don't see how your interpretation of 725.136(I)(2) permits a low voltage pair of wires to be enclosed within the same cable or raceway as conductors for light and power.

I would interpret that 725.136(I) refers to "Other Applications" such as when the 2 cables cross paths in general construction areas of buildings.

Well....I believe in quite a few previous posts I explained that but let's look at it this way so I don't want to be redundant. Also UL issued a CRD which permits the application and confirmed it meets Section 725.136(I)(2).

ok so let's look at 725.136(A)- General Rule

(A) General. Cables and conductors of Class 2 and Class 3
circuits shall not be placed in any cable, cable tray, com-
partment, enclosure, manhole, outlet box, device box, race-
way, or similar
fitting with conductors of electric light,
power, Class 1, nonpower-limited
re alarm circuits, and
medium-power network-powered broadband communica-
tions circuits unless permitted by 725.136(B) through (I).

So of the items in (B) through (I) the only option that applies to the Type MC Cable is (I). So this gives a separation specific to those issues not covered in (B) through (H). Now notice the allowances given in (I)(1) and (2) below:

(1) Either (a) all of the electric light, power, Class 1, non
power-limited fi
re alarm and medium-power network-
powered broadband communications circuit conductors
or (b) all of the Class 2 and Class 3 circuit conductors
are in a raceway or in metal-sheathed, metal-clad, non
metallic-sheathed, or Type UF cables.


(2) All of the electric light, power, Class 1 nonpower-limited

re alarm, and medium-power network-powered broad-
band communications circuit conductors are permanently
separated from all of the Class 2 and Class 3 circuit con-
ductors by a continuous and
firmly
fixed nonconductor,
such as porcelain tubes or exible tubing, in addition to
the insulation on the conductors.

Both of these options were expressed in the UL CRD and meeting the NEC 725.136(I)(1) and (2). The jacket on the Class 2 conductors were increased to 30 mils (like Type NM-B) to meet (I)(1). Without a set standard for the jacket thickness the equivalent Type NM-B was chosen.

My previous posts go into more detail but beyond that I guess we would have to agree to disagree....but we all make it now and it's called Type MC-PCS.

Hope this helped..if any

 

[don_resqcapt19]

...
Both of these options were expressed in the UL CRD and meeting the NEC 725.136(I)(1) and (2). The jacket on the Class 2 conductors were increased to 30 mils (like Type NM-B) to meet (I)(1). Without a set standard for the jacket thickness the equivalent Type NM-B was chosen.
...

So if I have a Class 2 cable with a 30 mil jacket, I can pull it in with power conductors in a raceway and it would be code compliant.

 

[shortcircuit2]

I disagree with this interpretation. The Manufacturers have twisted the meaning and intent of 725.136(I) and somehow convinced UL that it is OK to put a LOW VOLTAGE circuit conductor in the same cable as circuits for Light and Power.

This is against everything that I have been taught regarding low voltage and line voltage in the same raceway or cable. I would like to see the attendance list and the minutes from that meeting.

 

[MasterTheNEC]

So if I have a Class 2 cable with a 30 mil jacket, I can pull it in with power conductors in a raceway and it would be code compliant.

You can't...We Can and do with our Type MC CABLE.....like we do with Type MC-LED...but if done in accordance with Section 725.136(I)(1) the answer is yes, The separation in the general statement of (I) is applicable, which is 2" unless (I)(1) or (I)(2) can be applied...

In our case (along with other manufacturers) as long as the Type MC-PCS is constructed in accordance with UL 1569 and the published and accepted CRD is met which explains the application of 725-136(I)(1) and (2) then it is perfectly code compliant.

 

[don_resqcapt19]

You can't...We Can and do with our Type MC CABLE.....like we do with Type MC-LED...but if done in accordance with Section 725.136(I)(1) the answer is yes, The separation in the general statement of (I) is applicable, which is 2" unless (I)(1) or (I)(2) can be applied...

In our case (along with other manufacturers) as long as the Type MC-PCS is constructed in accordance with UL 1569 and the published and accepted CRD is met which explains the application of 725-136(I)(1) and (2) then it is perfectly code compliant.

I guess my point is there is no reason that a cable manufacture cannot make a Class 2 cable with a "NM" jacket, and if they do, we can pull it in the conduit with the power conductors.

 

[MasterTheNEC]

I guess my point is there is no reason that a cable manufacture cannot make a Class 2 cable with a "NM" jacket, and if they do, we can pull it in the conduit with the power conductors.

Well the hang up is UL 13, some manufacturers just buy the Class 2 Cables already constructed and evaluated and then place it into the metal-clad cable. Believe it or not sometimes you can buy volumes of a Class 2 cable for use with a product like Type MC and it's actually cheaper than making it yourself...plus it is already evaluated and so on.

But the long and short....Yes

 

[shortcircuit2]

You can't...We Can and do with our Type MC CABLE.....like we do with Type MC-LED...but if done in accordance with Section 725.136(I)(1) the answer is yes, The separation in the general statement of (I) is applicable, which is 2" unless (I)(1) or (I)(2) can be applied...

In our case (along with other manufacturers) as long as the Type MC-PCS is constructed in accordance with UL 1569 and the published and accepted CRD is met which explains the application of 725-136(I)(1) and (2) then it is perfectly code compliant.

I still disagree and would like to see the ROP for 725.136 when it was drafted. Actually 725.136 was 725.55(J) in the 2002 NEC.

When I look at what is allowed for Class 1 circuits in part II of 725 under 725.48, class 1 circuits occupying the same raceway or cable as power conductors is only allowed where the equipment powered is functionally associated.

Then I look to part III of 725 for class 2+3 circuits...725.139 says absolutely nothing of class 2+3 circuits being allowed in the same raceway or cable with power conductors.

The NEC would have similar language in part III for class 2+3 circuits like in 725.48(B)(1) for class 1 circuits.

I disagree with the way 725.136 is being applied to these hybrid cables. Speaking of hybrid cables...the now gone Article 780 used to have language allowing LISTED hybrid cables under 780.6(A) and communications and signaling conductors were allowed within the same cable jacket.

I can see the need for your dimming cable, but I don't see that the NEC allows it...725.136(A) prohibits it.

 

[don_resqcapt19]

I still disagree and would like to see the ROP for 725.136 when it was drafted. Actually 725.136 was 725.55(J) in the 2002 NEC. ...

You can look at a lot of the older ROPs and ROCs here.

 

[shortcircuit2]

Thanks for the link Don.

I researched back to 1965 NEC. There is not really any ROC or ROP back then. The NEC review was call the "ADVANCE REPORTS". The applicable article in the 1965 NEC is 725-42 and this is the section which led to todays 2014 NEC 725.136 (well 1965 is as far back as I spent looking)

The 1965 NEC 725-42(a)(1) Open Conductors. Conductors shall be separated at least 2 inches from any light and power conductors not in a raceway unless permanently separated from the conductors of the other system by a continuous and firmly fixed nonconductor, such as porcelain tubes or flexible tubing, additional to the insulation of the conductor.

The 1965 NEC 725-42(a)(2) In Raceways and Boxes. Conductors of Class 2 remote-control and signal circuits shall not be placed in any raceway, compartment, outlet box or similar fitting with conductors for either light and power circuits or Class 1 signal and control circuits, unless the conductors of the different systems are separated by a partition; provided that this shall not apply to conductors in outlet boxes, junction boxes or similar fittings or compartments where power supply conductors are introduced solely for supplying power to remote-control or signal equipment to which the conductors in the enclosure are connected.

The 1965 NEC 725-42(a)(3) In Shafts. Conductors may be run in the same shaft with conductors for light and power where the conductors of the two systems are separated at least 2 inches, or where the conductors of either system are encased in noncombustible tubing.

This language basically stayed like this until 1992. In 1992, section 725-42 was newly created into 725-52 (Log #1041) by Irving Mande of Wspt., CT for the 1993 NEC...725-52(a)(1) Open Conductors and (a)(4) In Shafts was still used. Language was added to include nonpower-limited fire protective signaling circuits.

In 1995, article 725 was totally reorganized by William L. Schallhammer of Northbrook , IL (Log #2703) This was the year the ROP revised the 725-52(a)(1) Open Conductors and (a)(4) In Shafts into what we have today which is referred to as OTHER APPLICATIONS

OTHER APPLICATIONS was created to eliminate the term OPEN CONDUCTORS because there was no definition of open conductors in the Code. Also 725-52(a)(4) In Shafts was also added to Other Applications, as the same considerations apply. The revised 725-52 (a) (1) + (4) became 725-54 Other Applications. in the 1996 NEC. The exceptions or conditions as they are called in the NEC now, are the same today as they were in the 1996 NEC and are similar to the language used back in the 1965 NEC. These exceptions where intended for applications of Class 2 circuits installed near open conductors or installations in shafts. The intention is to keep the conductors separated...not install them in the same raceway or cable.

The conditions of separation by "Porcelain Tubes" and "Flexible Tubing" came from the use of porcelain tubes in those days and flexible tubing was readily available from machine parts supplier's...(Noted from panel comments). These 2 methods or materials probably could use some revision IMO.

Many of the submitted revisions over the years have attempted to put low voltage wiring in the same raceway as power wiring and they have been rejected.

Once again I will say I see the need for the Hybrid Dimming Cable, but I disagree 725.136(I)(1) or (2) allows it.

 

[MasterTheNEC]

Once again I will say I see the need for the Hybrid Dimming Cable, but I disagree 725.136(I)(1) or (2) allows it.

Still perplexed at that part of it you do not get.....

The Article is 725 which is dealing with Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power Limited Circuits.......Correct...

The issue is the separation requirements for Electric Light and Power from Class 2 and Class 3 circuits......Correct...

Here is the charging statement of 725.136....in its entirety.

"Section 725.136(A) General. Cables and conductors of Class 2 and Class 3 circuits shall not be placed in any cable, cable tray, compartment, enclosure, manhole, outlet box, device box, raceway,or similar fitting with conductors of electric light, power, Class 1, non?power-limited fire alarm circuits, and medium-power network-powered broadband communications circuits unless permitted by 725.136(B) through (I)."

Now cable is mentioned in 725.136(A)..correct.....which of the items (B) through (I) do you feel address the cable?

The only item that deals with and the mention of cables is item (I).....which as stated in 725.136(A) as "unless permitted by 725.136(B) through (I)......and (I) permits it and underwriters laboratory agrees and has put our an CRD on the subject.

So I am still not sure which part of it you do not agree with....or where the hazard lies to not agree with it.

 

[shortcircuit2]

I gave my reasons above in my last post. The NEC doesn't allow the Luminary Cable per 725.136(A)...

And (I) Other Applications. only allows less than 2-inches of separation when condition (1) or (2) is met...and those conditions were NOT intended to allow installation of the circuits inside the same cable.

The danger...cable failure, damage and inadvertent use of the product leading to dangerous voltages on class 2 and class 3 circuits and equipment which may cause fire, injury or death.

 

[MasterTheNEC]

I gave my reasons above in my last post. The NEC doesn't allow the Luminary Cable per 725.136(A)...

And (I) Other Applications. only allows less than 2-inches of separation when condition (1) or (2) is met...and those conditions were NOT intended to allow installation of the circuits inside the same cable.

The danger...cable failure, damage and inadvertent use of the product leading to dangerous voltages on class 2 and class 3 circuits and equipment which may cause fire, injury or death.

its not luminary cable...its Type MC Cable under UL 1569......Gesh..Have you even read the CRD from UL?

 

[shortcircuit2]

MC cable alright...one that conflicts with the requirements of the NEC.

1.Section 725.179(K) requires low voltage cables to be Marked as part of the listing.
2.Table 725.179(K) gives a list of the required marking/cable types.
3.There is no Marking on the low voltage wires in the new hybrid MC.
4.The unmarked TFN conductors are not a permitted wiring method as required by 725.130(B)

Post the CRD please.

 

[MasterTheNEC]

MC cable alright...one that conflicts with the requirements of the NEC.

1.Section 725.179(K) requires low voltage cables to be Marked as part of the listing.
2.Table 725.179(K) gives a list of the required marking/cable types.
3.There is no Marking on the low voltage wires in the new hybrid MC.
4.The unmarked TFN conductors are not a permitted wiring method as required by 725.130(B)

Post the CRD please.

There are markings....the CDR permits it to be on the identification strip that is inside the cable....we place it inside the cable just on the Mylar (polymeric wrap) or as a separate ID strip.........find it ironic that you would say UL is wrong when they are the ones who determine the construction of a product...the NEC points to listed products and that listing comes from being evaluated and built to UL standards.

The CRD is too large as it exceeds the PDF size.....if you PM me an email to send it to I will do so first thing Monday morning.

 

[MasterTheNEC]

MC cable alright...one that conflicts with the requirements of the NEC.

1.Section 725.179(K) requires low voltage cables to be Marked as part of the listing.
2.Table 725.179(K) gives a list of the required marking/cable types.
3.There is no Marking on the low voltage wires in the new hybrid MC.
4.The unmarked TFN conductors are not a permitted wiring method as required by 725.130(B)

Post the CRD please.

I also wanted to add.....Your points are very valid and I did not want to convey otherwise. I can only tell you from extensive conversations with UL (as all of the wire and cable people have....since the inception of this product) that since the binder (nonmetallic sheathing .30 mils) is inside of a listed Type MC Construction and that the exact wording associated with being a Type MC-PCS product that has equivalent insulation values as the power/lighting conductors have that it did not have to be individually labeled as denoted in Section 725.179(K).

The markings are either on the internal strip or on the products surface but that is left up to the manufacturer in the CRD. The concept was that it is considered a group in terms of length of lay and was constructed under UL 1569 guidance as a complete assembly and not as a separate Class 2 Cable....that is why the entire assembly and the CRD is set to include the unique cable design under UL 1569 as a whole and to not require the Class 2 equivalent inners to have to be individually rated.

I can only be the messenger.....if the industry chooses to reject the cables (we all make it the same way) then show me the hazard it presents.

I would also point you to Section 402.3 and TFN. It is very common to use Type TFN for low voltage applications and UL acknowledges that.

402.3 Types.

Fixture wires shall be of a type listed in Table

402.3, and they shall comply with all requirements of that
table. The fixture wires listed in Table 402.3 are all suitable for
service at 600 volts, nominal, unless otherwise specified.


*Insulations and outer coverings that meet the requirements of flame retardant, limited smoke, and are so

listed, shall be permitted to be marked for limited smoke after the Code type designation.

 

[MasterTheNEC]

CRD for the Type MC-PCS has been attached as promised.