Wire insulation in same raceways must match

[wireman]

I know it's in the NEC somewhere but I can't seem to find it.
Isn't it a violation to run low voltage (say 300V) Belden cable in the same raceway as 600VAC rated wire?

Would someone point me to the correct section?

Thanks in advance.

 

[infinity]

Look here and specifically at IN #1.

300.3(C) Conductors of Different Systems.
(1) 1000 Volts, Nominal, or Less. Conductors of ac and dc
circuits, rated 1000 volts, nominal, or less, shall be permit-
ted to occupy the same equipment wiring enclosure, cable,
or raceway. All conductors shall have an insulation rating
equal to at least the maximum circuit voltage applied to any
conductor within the enclosure, cable, or raceway.
Secondary wiring to electric-discharge lamps of 1000
volts or less, if insulated for the secondary voltage involved, shall be permitted to occupy the same luminaire,
sign, or outline lighting enclosure as the branch-circuit conductors.
Informational Note No. 1: See 725.136(A) for Class 2 and
Class 3 circuit conductors.
Informational Note No. 2: See 690.4(B) for photovoltaic
source and output circuits.

 

[petersonra]

beyond what the second poster mentioned there are some restrictions on running Article 725 circuits in the same conduit as power circuits.

 

[GoldDigger]

Note that 300.3(C) only requires that all insulation, at a minimum, be rated for the highest circuit voltage. So if the power circuit is 120V or 120/240 having the power wiring insulation be rated for 600V (higher than required) does not require the other circuit to be rated higher than 300V.

 

[hbiss]

I know it's in the NEC somewhere but I can't seem to find it.
Isn't it a violation to run low voltage (say 300V) Belden cable in the same raceway as 600VAC rated wire?

300.3(C)(1) allows conductors to occupy a raceway as long as all have an insulation rating
equal to at least the maximum circuit voltage applied to any conductor within the enclosure, cable, or raceway. HOWEVER that is only for power, lighting and Class 1 circuits. If you are talking about CL2 or CL3 LV circuits then you get into the whole quagmire of Art. 725. We just had yet another discussion over the never ending confusion about running 0-10V LV dimming with the line voltage to a fixture.

Rather than rehash it all again go here- http://forums.mikeholt.com/showthread.php?t=189472

-Hal

 

[Muhammad0092]

Hey Guys every one talking about Art 725 which prohibits to use same race way. But please don’t mix and match hazards class 2 and class 3 wiring with general wiring or unclassified wiring. Art 725 just applied on Hazards locations. Think about are we using same wiring methods what we are using in general wiring or unclassified locations? No. Then why we making confusion with class 2 or class 3 hazards location wiring with unclassified wiring methods.

 

[texie]

Hey Guys every one talking about Art 725 which prohibits to use same race way. But please don’t mix and match hazards class 2 and class 3 wiring with general wiring or unclassified wiring. Art 725 just applied on Hazards locations. Think about are we using same wiring methods what we are using in general wiring or unclassified locations? No. Then why we making confusion with class 2 or class 3 hazards location wiring with unclassified wiring methods.

You are seriously misunderstanding what Article 725 circuit classifications are. This has nothing to do with hazardous location Classes (which by the way are expressed as roman numerals).

 

[Muhammad0092]

You are seriously misunderstanding what Article 725 circuit classifications are. This has nothing to do with hazardous location Classes (which by the way are expressed as roman numerals).

We having a lot misunderstanding of this article. Look these are power limited circuits, where we use power limited circuits? To prevent the fire hazardous. Look the definition of this article. Class 1 is power limited circuit . Period, so why we are mixing our power limited circuits with normal general power wiring. Now let me ask you one question, the article 725.48(A) you guys are giving ref, Q. are we allow to run D.C wiring in our general wiring raceway? Ans is No . Look article 690.31B will not allow us D.C and A.C contains same raceway. Now why not this article should apply when we run d.c separate than A.c. 725.48b allow us to run d.c and a.c in same recreational right . But we don’t do that because this article apply only for power limited circuits. And power limited circuits we always use in hazardous locations. Class 1 circuit allow us only 30 volt or 100 volt amp. Other than we have to use impedance devices to control the current limits where we are exceeding 100 volts amps. Or we using these techniques in general wiring methods . No . So please guys make sure don’t mix and completely different nut shell with general wiring.

 

[hbiss]

We having a lot misunderstanding of this article.

Yes, you do.

-Hal

 

[Muhammad0092]

Yes, you do.

-Hal

could you explain how and why I am wrong?

 

[Muhammad0092]

could you explain how and why Am I wrong?

 

[roger]

could you explain how and why I am wrong?

Classes 1, 2, and 3 in chapter 7 do not have the same meaning as in classes I, II, and III in chapter 5 hazardous location classifications.

Roger

 

[kwired]

I don't think he is confusing this with chapter 5 hazardous locations though he keeps using that word hazardous and mixing fire in there and makes it read as though he is confusing it with chapter 5 hazardous locations requirements to some extent.

725 covers remote control, signaling and power limited circuits.

not all the remote control or signaling circuits are power limited, there can be different requirements when they are not power limited vs when they are.

The general rule is all these circuits must be separated from light and power circuits with exception for class 1 or anything reclassified class 1 can often be run with light or power conductors that it is associated with. A motor circuit and it's control conductors can be run in same raceway in some conditions is one example.

Muhammad009 I suggest you take a look at 725.41 and read it carefully this time if you already have looked at it.

(A) does cover class 1 power limited circuits and does have many the things you have mentioned for requirements.

(B) is for all the other class 1 remote control and signaling circuits, can be up to 600 volts and has no power limitation requirements.

Then there is rules in other sections that allow reclassifying say a class 2 power circuit to class 1 in some situations but along with that you typically end up removing the class 2 marking from the source and then install the entire circuit as a class 1 circuit, which means no use of CL2 or 3 cables, no CL2 or 3 only rated devices, etc.

 

[paulengr]

Chapter 7 wiring is for signaling and communication. As an example all general power wiring (chapters 1-4)has a minimum size of 18 gauge. This is to ensure a large enough conductor that it survives long enough to clear faults.

The 100 MBps Ethernet specification has such a low cable capacitance requirement that wire gauges cannot be larger than #22. Thus Ethernet communication cables are illegal under the general wiring rules (chapters 1-3). They fall under the classifications in chapter 7. This is not an insulation issue. Belden and Commscope make CAT 5E with a 600 V rating which could clearly meet chapter 1-3 requirements except for the wire gauge so it is rated AWM (components, not assemblies) and PLTC (Chapter 7) only.

You are confusing this with for instance intrinsically safe wiring rules which are also power limited but also energy limited. IS wiring is ANY wiring scheme (chapters 1-3 or 7). The energy limitation is on the sources and the loads. There is no limitation at all on mixing it with other wiring in the same raceway although the non-IS wiring is subject to chapter 5 installation requirements so I’m not sure why you would do this.