Combining circuit types in a conduit

[dkone]

[FONT=verdana, geneva, lucida, lucida grande, arial, helvetica, sans-serif]Hi, I'm a new member and this is my first post. I have posted this same question in 3 other forums and only received a related reply in one, as well as a private message from someone there to try the Mike Holt forum. I am not shopping for an answer that suits me, just an answer to the question.[/FONT]

The company I work for does service work at retail gas stations, specifically the pump and tank work. We have two electricians on staff for service/small job work. No real heavy electrical work, when we build a new station we sub out the electric. One of the tasks our electricians perform on a routine basis is to replace the gas dispensers with new models. The challenge we come up against quite frequently at older stations is there is only on conduit to the gas dispenser. A modern gas dispenser needs three circuit types, a Class 1 for the power, a Class 2 or 3 for the intercom, and a communications circuit in the form of Cat. 5 cable rated for a hazardous location. My question has to do with combining all three circuit types into that one conduit. I think it can be done per code, but can someone confirm? Here is why I think it can be done:

[FONT=verdana, geneva, lucida, lucida grande, arial, helvetica, sans-serif]The Class 2/3 circuit can be reclassified and combined in a raceway with a Class 1 circuit per Sec. 725.130 as long as you remove the circuit classification markings of the equipment per Sec. 725.124 and follow all C1 wiring methods. The one I am struggling with is the communications circuit (it is not a PoE circuit, just a plain old data cable). The best I can come up with is Exception No. 3 of Sec. 800.133, which leads you to Sec. 620.36. To me this says you can do it as long as your communications wire is rated the same as your Class 1 wire. Where I am doubting this is that Art. 620 deals with Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts. So what takes precedence? The fact that Code exists that allow for the combining of communications & Class 1 or the equipment listed in the title of Art. 620? Is my interpretation correct regarding the reclassification of C2 circuits per 724.130?[/FONT]

Any advice would be appreciated.

To try an stem off the same off topic responses I received in other forums.
Yes I know it is a class 1 div 1 location, or at least we pass through it.
Yes the cat 5 cable is rated for hazardous locations.
Yes the work requires a permit.
No the canopy lights circuits are not in the conduit going to the dispenser.
We don't need to hire a qualified electrical sub contractor or an electrical engineer for the work. (this was my favorite)
I am sure there are wireless intercom systems available, but that is not what I am asking about.
The reclassified circuits do have functional association with the c1 circuit in the fact that the intercom and data component of the dispenser are integral components of the same UL listed assembly, ie.. they make up the entire dispenser.
The cost of adding additional conduits to the dispenser is on average 20K, and yes we would love to do it as a change order for every single job. I just want a code reference or some type of backing that says we can or can't do it.

Here are my code citations (from 2014)

NEC 2014 800.133

800.133 Installation of Communications Wires, Cables, and Equipment. Communications wires and cables from the protector to the equipment or, where no protector is required, communications wires and cables attached to the outside or inside of the building shall comply with 800.133(A) and (B).
(A) Separation from Other Conductors.
(1) In Raceways, Cable Trays, Boxes, Cables, Enclosures, and Cable Routing Assemblies.
(a) Optical Fiber and Communications Cables. Communications cables shall be permitted in the same raceway, cable tray, box, enclosure, or cable routing assembly with cables of any of the following:
(1) Nonconductive and conductive optical fiber cables in compliance with Parts I and V of Article 770
(2) Community antenna television and radio distribution systems in compliance with Parts I and V of Article 820
(3) Low-power network-powered broadband communications circuits in compliance with Parts I and V of Article 830
(b) Other Circuits. Communications cables shall be permitted in the same raceway, cable tray, box, enclosure, or cable routing assembly with cables of any of the following:
(1) Class 2 and Class 3 remote-control, signaling, and power-limited circuits in compliance with Article 645 or Parts I and III of Article 725
(2) Power-limited fire alarm systems in compliance with Parts I and III of Article 760
(c) Class 2 and Class 3 Circuits. Class 1 circuits shall not be run in the same cable with communications circuits. Class 2 and Class 3 circuit conductors shall be permitted in the same cable with communications circuits, in which case the Class 2 and Class 3 circuits shall be classified as communications circuits and shall meet the requirements of this article. The cables shall be listed as communications cables.
Exception: Cables constructed of individually listed Class 2, Class 3, and communications cables under a common jacket shall not be required to be classified as communications cable. The fire-resistance rating of the composite cable shall be determined by the performance of the composite cable.
(d) Electric Light, Power, Class 1, NonPower-Limited Fire Alarm, and Medium-Power Network-Powered Broadband Communications Circuits in Raceways, Compartments, and Boxes. Communications conductors shall not be placed in any raceway, compartment, outlet box, junction box, or similar fitting with conductors of electric light, power, Class 1, nonpower-limited fire alarm, or medium-power network-powered broadband communications circuits.
Exception No. 1: Where all of the conductors of electric light, power, Class 1, nonpower-limited fire alarm, and medium-power network-powered broadband communications circuits are separated from all of the conductors of communications circuits by a permanent barrier or listed divider.
Exception No. 2: Power conductors in outlet boxes, junction boxes, or similar fittings or compartments where such conductors are introduced solely for power supply to communications equipment. The power circuit conductors shall be routed within the enclosure to maintain a minimum of 6 mm (0.25 in.) separation from the communications circuit conductors.
Exception No. 3: As permitted by 620.36.


NEC 2014 620.36

620.36 Different Systems in One Raceway or Traveling Cable. Optical fiber cables and conductors for operating devices, operation and motion control, power, signaling, fire alarm, lighting, heating, and air-conditioning circuits of1000 volts or less shall be permitted to be run in the same traveling cable or raceway system if all conductors are insulated for the maximum voltage applied to any conductor within the cables or raceway system and if all live parts of the equipment are insulated from ground for this maximum voltage. Such a traveling cable or raceway shall also be permitted to include shielded conductors and/or one or more coaxial cables if such conductors are insulated for the maximum voltage applied to any conductor within the cable or raceway system. Conductors shall be permitted to be covered with suitable shielding for telephone, audio, video, or higher frequency communications circuits.


NEC 2014 article 725.130

725.130 Wiring Methods and Materials on Load Side of the Class 2 or Class 3 Power Source. Class 2 and Class 3 circuits on the load side of the power source shall be permitted to be installed using wiring methods and materials in accordance with either 725.130(A) or (B).

(A) Class 1 Wiring Methods and Materials. Installation shall be in accordance with 725.46.
Exception No. 1: The ampacity adjustment factors given in 310.15(B)(3)(a) shall not apply.
Exception No. 2: Class 2 and Class 3 circuits shall be permitted to be reclassified and installed as Class 1 circuits if the Class 2 and Class 3 markings required in 725.124 are eliminated and the entire circuit is installed using the wiring methods and materials in accordance with Part II, Class 1 circuits.
Informational Note: Class 2 and Class 3 circuits reclassified and installed as Class 1 circuits are no longer Class 2 or Class 3 circuits, regardless of the continued connection to a Class 2 or Class 3 power source.

 

[luckylerado]

The power wiring is not Class 1. 620 does not apply. Communications circuits need to be separated from power. Although I do not doubt it will "work" I do not know how to combine the circuits that you describe in a single raceway and be compliant with NEC much less in a dispensing station.

That said, I have seen some pretty unique listed Mil-Spec cable assemblies that would do it but be prepared to mortgage the farm.

 

[GoldDigger]

Although there may be some additional restrictions that affect the gas station case, it should be possible to combine the three types of circuit in one conduit as long as each circuit type is run in its own cable which is, by itself, a complete Chapter 3 wiring method. In effect the pipe becomes just a single sheath around the three cables.
But that could certainly have some impact on the sealing techniques required for all three independently and the sheath in addition.

 

[hbiss]

The reclassified circuits do have functional association with the c1 circuit in the fact that the intercom and data component of the dispenser are integral components of the same UL listed assembly, ie.. they make up the entire dispenser.

I don't agree that there is a functional association except for maybe the data. The pump can certainly operate without the intercom. If there is no functional association then there can be no reclassification so your CL2 wiring is out.

What it boils down to is that if you can forgo the intercom you can pull your CAT5 in with the power ASSUMING that it is listed class 1 (which I believe they do make) AND is listed for wet locations since your conduit is underground. I may be wrong but I don't think you are going to find such an animal.

The right way to do this is to just assume you need to install new conduit runs whenever you replace the pumps. If you are replacing the tanks at the same time it shouldn't be a big deal.

-Hal

 

[augie47]

Fuel dispenser wiring has changed so much over the years that I, for one, have a difficult time keeping up and this may be the case here.
In this area most of the dispensers I deal with are Wayne brand and from their manual and from what I read in the NEC the intercom must be in a seperate conduit.
FWIW here is a link to the Wayne manual I see:

http://www.manualslib.com/manual/825982/Wayne-Ovation.html?page=19#manual


In contains this info:
The field Ethernet cable and Intercom (Call Button and Speaker) wires (NEC Class 2) must be installed via a separate underground conduit to the dispenser. The intercom/speaker and call button wires should be terminated with wire nuts in the electronics head

I find nothing in Art 514 or Art 800 that deviates from that.

 

[JFletcher]

welcome to the forum. what code cycle are you under?

 

[dkone]

welcome to the forum. what code cycle are you under?

Thanks for the welcome.

In PA we must obtain a State Flammable & Combustible permit for this type of work. The have their own set of safety regs plus as part of the law, they specifically adopt NFPA 70-1981, but inspect against current version. It is confusing at times.

For the local building permit, we are under IBC/IEC 2009, soon to go to 2015, and if I am not mistaken IBC references NFPA-70 as current version.

What I quoted in my original post was from 2014.

 

[dkone]

Fuel dispenser wiring has changed so much over the years that I, for one, have a difficult time keeping up and this may be the case here.
In this area most of the dispensers I deal with are Wayne brand and from their manual and from what I read in the NEC the intercom must be in a seperate conduit.
FWIW here is a link to the Wayne manual I see:

http://www.manualslib.com/manual/825982/Wayne-Ovation.html?page=19#manual


In contains this info:
The field Ethernet cable and Intercom (Call Button and Speaker) wires (NEC Class 2) must be installed via a separate underground conduit to the dispenser. The intercom/speaker and call button wires should be terminated with wire nuts in the electronics head

I find nothing in Art 514 or Art 800 that deviates from that.

We are a Wayne distributor and authorized repair company. I am aware of the instructions in the manual. We have had dialog with Wayne and have a statement from them in which the first sentence reads:

"Dresser Wayne agrees with the following exception to the NEC if only one conduit is available for dispenser installation:"

He then goes on to quote 725.130 from NEC 2008.

 

[dkone]

I don't agree that there is a functional association except for maybe the data. The pump can certainly operate without the intercom. If there is no functional association then there can be no reclassification so your CL2 wiring is out.

What it boils down to is that if you can forgo the intercom you can pull your CAT5 in with the power ASSUMING that it is listed class 1 (which I believe they do make) AND is listed for wet locations since your conduit is underground. I may be wrong but I don't think you are going to find such an animal.

The right way to do this is to just assume you need to install new conduit runs whenever you replace the pumps. If you are replacing the tanks at the same time it shouldn't be a big deal.

-Hal

Hal, can you clarify something you said? "AND is listed for wet locations since your conduit is underground" Are you saying that only applies to the comm cable IF it is in the same conduit with other circuit types? Or are you saying that the comm cable would have to be listed for wet locations anytime it is installed (even if just by itself) in a conduit underground? We use Beldon 7928A, which is listed for as a oil & gas resistant cable, but it makes no mention of being listed for a wet location.

The dispenser is capable of running without a network connection or an intercom, those two items only make it function either more efficiently (comm cable for processing credit cards) or to meet a State law (all dispensing operations at an attended self serve station must have a hands free communication device). If I am understanding your case about definition of functional association, then we would not be able to combine the CL2 circuit with the Comm cable. There is certainly no functional relationship between the credit card reader and the intercom. So each dispenser would really need up to 4 conduits; 1 for CL1, 1 for CL2, 1 for Comm and 1 for intrinsically safe. I didn't bring up the safe wiring in my initial thread because I am only talking about a specific case of replacing a dispenser at an existing location that only has 1 conduit to the dispenser and because sensors are not always present or required. The case only rears its ugly head at much older stations that pre-date credit card readers in dispensers (CRINDS) and the intercom being built into the dispenser. Back then you only need one conduit for high and that was it.

 

[dkone]

The power wiring is not Class 1. 620 does not apply. Communications circuits need to be separated from power. Although I do not doubt it will "work" I do not know how to combine the circuits that you describe in a single raceway and be compliant with NEC much less in a dispensing station.

That said, I have seen some pretty unique listed Mil-Spec cable assemblies that would do it but be prepared to mortgage the farm.

I think you may have just clarified this for me at least on the intercom c2 part of my post. You are correct, the power wiring is not a CL1 circuit, I was thinking of the pump control circuit. This means it can't be combined it with a CL2 circuit at least as per 725.

I got to 620 via 800.133 via exception 3. When 620 comes into play I question how to interpret it, which is the primary reason for my post. The first sentence of 620.36 appears to cover power circuits as being allowed to be combined with a comm circuit. Am I reading that wrong?

No farm mortgaging for me, we pay through the nose for the oil/gas rated cat5 cable as it is.

 

[luckylerado]

620 comes into play I question how to interpret it, which is the primary reason for my post. The first sentence of 620.36 appears to cover power circuits as being allowed to be combined with a comm circuit. Am I reading that wrong?

Yes, you are taking this section out of context. It cannot be shoehorned to fit every situation. 620 scope is as follows:

This article covers the installation of electrical equipment and
wiring used in connection with elevators, dumbwaiters, escalators,
moving walks, platform lifts, and stairway chairlifts.

I am fairly certain that you can find a cable that is manufactured to suit your needs.Probably very similar to an elevator traveling cable.

 

[gadfly56]

Hal, can you clarify something you said? "AND is listed for wet locations since your conduit is underground" Are you saying that only applies to the comm cable IF it is in the same conduit with other circuit types? Or are you saying that the comm cable would have to be listed for wet locations anytime it is installed (even if just by itself) in a conduit underground? We use Beldon 7928A, which is listed for as a oil & gas resistant cable, but it makes no mention of being listed for a wet location.

The dispenser is capable of running without a network connection or an intercom, those two items only make it function either more efficiently (comm cable for processing credit cards) or to meet a State law (all dispensing operations at an attended self serve station must have a hands free communication device). If I am understanding your case about definition of functional association, then we would not be able to combine the CL2 circuit with the Comm cable. There is certainly no functional relationship between the credit card reader and the intercom. So each dispenser would really need up to 4 conduits; 1 for CL1, 1 for CL2, 1 for Comm and 1 for intrinsically safe. I didn't bring up the safe wiring in my initial thread because I am only talking about a specific case of replacing a dispenser at an existing location that only has 1 conduit to the dispenser and because sensors are not always present or required. The case only rears its ugly head at much older stations that pre-date credit card readers in dispensers (CRINDS) and the intercom being built into the dispenser. Back then you only need one conduit for high and that was it.

Their 7937A would be suitable for direct burial, and 7934A is suitable for direct burial and is oil resistant but not gas resistant.

 

[don_resqcapt19]

Hal, can you clarify something you said? "AND is listed for wet locations since your conduit is underground" Are you saying that only applies to the comm cable IF it is in the same conduit with other circuit types? Or are you saying that the comm cable would have to be listed for wet locations anytime it is installed (even if just by itself) in a conduit underground? We use Beldon 7928A, which is listed for as a oil & gas resistant cable, but it makes no mention of being listed for a wet location.

It must always be a wet location cable ...see 725.3(L).

The dispenser is capable of running without a network connection or an intercom, those two items only make it function either more efficiently (comm cable for processing credit cards) or to meet a State law (all dispensing operations at an attended self serve station must have a hands free communication device). If I am understanding your case about definition of functional association, then we would not be able to combine the CL2 circuit with the Comm cable. There is certainly no functional relationship between the credit card reader and the intercom. So each dispenser would really need up to 4 conduits; 1 for CL1, 1 for CL2, 1 for Comm and 1 for intrinsically safe. I didn't bring up the safe wiring in my initial thread because I am only talking about a specific case of replacing a dispenser at an existing location that only has 1 conduit to the dispenser and because sensors are not always present or required. The case only rears its ugly head at much older stations that pre-date credit card readers in dispensers (CRINDS) and the intercom being built into the dispenser. Back then you only need one conduit for high and that was it.

In my opinion the CL2 cables and the comm cables can be in a single conduit. I just don't see any provision that would permit them to be in with pump power in a common conduit. As I said in the other forum, if I was inspecting or reviewing your permit application, I would require additional conduits.

You have added IS circuits that I did not see before...those can never be in a raceway with conductors of other systems, so if you have power, comms, and IS, you will need 3 conduits.

 

[tom baker]

Would it work to use a fiber optic cable, for intercom and data? As long as the fiber is non conductive it can be with power, however this is for non hazardous locations and I am not able to dig into art 500 applications for fiber.

 

[JFletcher]

I've been thinking some more about this. Even if you can find a combo cable assembly to get around 725.136 (i think thats the main one) to use one conduit, such apps like elevators have cabinets designed or them. Are fuel pumps designed for this? I cant quite picture how you'd split out the individual cables on both ends in a compliant way.

 

[dkone]

Yes, you are taking this section out of context. It cannot be shoehorned to fit every situation. 620 scope is as follows:

This article covers the installation of electrical equipment and
wiring used in connection with elevators, dumbwaiters, escalators,
moving walks, platform lifts, and stairway chairlifts.

I am fairly certain that you can find a cable that is manufactured to suit your needs.Probably very similar to an elevator traveling cable.

Thanks, that answers one of my original questions from my initial post.

"Where I am doubting this is that Art. 620 deals with Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts. So what takes precedence? The fact that Code exists that allow for the combining of communications & Class 1 or the equipment listed in the title of Art. 620?"

 

[dkone]

It must always be a wet location cable ...see 725.3(L).

In my opinion the CL2 cables and the comm cables can be in a single conduit. I just don't see any provision that would permit them to be in with pump power in a common conduit. As I said in the other forum, if I was inspecting or reviewing your permit application, I would require additional conduits.

You have added IS circuits that I did not see before...those can never be in a raceway with conductors of other systems, so if you have power, comms, and IS, you will need 3 conduits.

The AHJ is of the same opinion for the CL2/Data in the same conduit.

IS is never an issue with the older stations where this case occurs. The IS circuit is only used for the sensors in the sumps beneath the dispensers. Most older locations pre-date regulation that require sumps. And even for the older locations with sumps, if they do have sensors there is already a separate conduit for the IS.

 

[don_resqcapt19]

The AHJ is of the same opinion for the CL2/Data in the same conduit. ...

Just to be clear...in the same conduit with each other, but not in a common conduit with power circuits.

 

[dkone]

Just to be clear...in the same conduit with each other, but not in a common conduit with power circuits.

Yes, CL2 and data in one conduit and power in separate conduit.

Also to be clear on a normal, brand new install or design, we always spec a high/low/safe conduit home run for each dispenser. The AHJ asked us to present evidence to back up several contractors claims that the NEC would allow for combining of circuits in a single conduit situation. The AHJ is trained in inspecting for the standards of their modified NFPA 30/30A regulations but are not professional electric inspectors. What I will be presenting to them is:

1. There is nothing in the NEC that would allow for a comm circuit to be combined with a power circuit at a gas station.
2. A CL2 could only be run with a power circuit if the following is true:
a. The AHJ must be of the opinion that the intercom is functionally related to the dispensers operation in regard to the power circuit
b. All components of the CL2 are rated for the power circuit and wired per wiring methods of art. 3 (this would be up to and including the speaker in the dispenser)

Since condition 2 would be impossible to meet due to the speaker and the 18ga wire from our termination point to the speaker, then effectively in this case the CL2 can't be combined with the power circuit via re-classification.

Would you say that is a fair summary of this thread?

 

[don_resqcapt19]

...
Would you say that is a fair summary of this thread?

I agree with the summary.