# Combining circuit types in a conduit



## dkone (May 20, 2016)

Hi, I'm a new member and this is my first post.

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:

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. 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?

Any advice would be appreciated.


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## MechanicalDVR (Dec 29, 2007)

First off, welcome aboard. Secondly while different circuits can be combined in the same conduit as long as the jacket insulation qualities are the same, in the work you do I would ask the AHJ and see if there could be local exceptions.


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## don_resqcapt19 (Jul 18, 2010)

dkone said:


> ...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:
> 
> 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. ....


While the code says that, it is my opinion that you have to have everything in the Class 2 or 3 circuit rated for the higher voltages, including the equipment that the wiring is connected to. 

It would not pass if I was inspecting. You would have to install an additional conduit for me. 

My issue is that the equipment installed in the gas pump which is a Class I, Division 1, location is not rated for the higher voltages and a short or other failure on the wiring would put line voltage on the equipment.

Also what do you do to comply with 514.11(A)?


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## dkone (May 20, 2016)

don_resqcapt19 said:


> While the code says that, it is my opinion that you have to have everything in the Class 2 or 3 circuit rated for the higher voltages, including the equipment that the wiring is connected to.
> 
> It would not pass if I was inspecting. You would have to install an additional conduit for me.
> 
> ...


For the C1 circuit we install a relay box tied into the E-stop to physically break the connection. For the data com and c2 circuit, one of the manufacturers that we rep, Power Integrity Corp., has a 'low voltage dispenser wiring disconnect' which does the disconnect.

I would love to put a new conduit in at each location, it is all change orders to us. The problem I run into is that the customer will not just let me have access to his wallet without justification. The issue we are running into is with the State inspector that is giving a reason similar to yours. When we ask for for the section(s) of NEC that says this is not allowed we are never given an answer.

Can you give me a specific code section that shows this as a violation? Or show me in the code where my interpretation is wrong. I need something solid that I can take back to the customer other than 'because the inspector said so'. At $10K + to add a new conduit, I need backup. If 10K seems high, it is actually on the low end for a single dispenser, remember this is all class 1 div 1 work, plus sump penetration, saw cutting, paving and hydrostatic testing of the modified sump, plus a DEP certified individual, onsite with the electrician. Most of the older stations have 2-4 dispensers.


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## dkone (May 20, 2016)

MechanicalDVR said:


> First off, welcome aboard. Secondly while different circuits can be combined in the same conduit as long as the jacket insulation qualities are the same, in the work you do I would ask the AHJ and see if there could be local exceptions.


Thanks for the welcome, this board seems much more active than some others I posted the same question.

The AHJ I am dealing with is the State of Dept. of Labor & Industry. They have some State specific requirements which modify NFPA 30 & 30A, but adopted 70 without modifications. There mantra of the inspectors has been, and I am not making this up. "We don't allow it because I say so". The current division chief is open to looking at the issue and I need some justification via the code that would allow for this. I think I am on the right track, but wanted to get some opinions (based the code) regarding the issues.


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## don_resqcapt19 (Jul 18, 2010)

> 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*.


In my opinion and that of a number of AHJs the wording in bold requires not just the wiring, but the equipment the wiring is connected to be suitable for the higher voltages.

You also have the question of the functional association of the reclassified communications circuits installed with the pump power circuits. Are they functionally associated with the power circuits? If they are not functionally associated, they can't be in the same conduit even where they have been reclassified.

That being said, if the local AHJ will not permit the use of a single conduit, your customer does not really have any choice...other that to peruse an lengthy challenge that may or may not result in permission to use a single raceway or to not install the project.


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## dkone (May 20, 2016)

don_resqcapt19 said:


> In my opinion and that of a number of AHJs the wording in bold requires not just the wiring, but the equipment the wiring is connected to be suitable for the higher voltages.
> 
> You also have the question of the functional association of the reclassified communications circuits installed with the pump power circuits. Are they functionally associated with the power circuits? If they are not functionally associated, they can't be in the same conduit even where they have been reclassified.
> 
> That being said, if the local AHJ will not permit the use of a single conduit, your customer does not really have any choice...other that to peruse an lengthy challenge that may or may not result in permission to use a single raceway or to not install the project.


The first sentence of 725.130 says that the circuit starts on the load side of the power source. So for the intercom, which is a c2 circuit, that would refer to the wire going to the speaker/mic. Are you saying the speaker/mic unit would be part of the circuit that must meet class 1 circuit requirements?

The exception listed for the com. cable is even more unclear to me, it only talks about the conductors being insulated for the max. voltage in the raceway. That was a paraphrase of 620.36.

As far as functional association, I would say yes. The intercom is built into the dispenser as are the components where the cat5 cable are connected. In order for the dispenser to operate properly it needs all three circuits.


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## mitch65 (Mar 26, 2015)

this may be sacrilegious, but are there wireless options for the communications equipment?


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## don_resqcapt19 (Jul 18, 2010)

dkone said:


> The first sentence of 725.130 says that the circuit starts on the load side of the power source. So for the intercom, which is a c2 circuit, that would refer to the wire going to the speaker/mic.* Are you saying the speaker/mic unit would be part of the circuit that must meet class 1 circuit requirements?*


*
*Yes, that is what I am saying.



> The exception listed for the com. cable is even more unclear to me, it only talks about the conductors being insulated for the max. voltage in the raceway. That was a paraphrase of 620.36.


There is nothing in Article 620 that applies to your installation. 



> As far as functional association, I would say yes. The intercom is built into the dispenser as are the components where the cat5 cable are connected. In order for the dispenser to operate properly it needs all three circuits.


Are you telling me that you can't pump gas if the intercom is not working? Are there any wires for canopy or pump lighting in the conduit?


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## dkone (May 20, 2016)

don_resqcapt19 said:


> [/B]Yes, that is what I am saying.
> 
> 
> There is nothing in Article 620 that applies to your installation.
> ...


Physically yes it can still pump gas, but State law requires a fully functional hands free communication device at all times during dispensing operations at an attended self serve station. The pump lights are low voltage lights from a transformer inside the dispenser which is fed from the C1 circuit. No canopy light wiring in the conduit that goes to the dispenser. Canopy lights circuit(s) are in a separate conduit that goes to the canopy column.

I ended up at 620 via exception #3 of 800.133:
Exception No. 3: As permitted by 620.36.

My original question about 620 was; does it only apply to the equipment listed in the title of article 600 or can it apply because 800.133 sent me there and because 620.36 specifically mentions "higher frequency communications circuits"?


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## dkone (May 20, 2016)

mitch65 said:


> this may be sacrilegious, but are there wireless options for the communications equipment?


I am sure there are some stand alone wireless units. The ones we deal with tie into the built in speaker/mic that is an integral part of the dispenser. Even if we did find a wireless solution, the cable that we must have is the data com cable.


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## don_resqcapt19 (Jul 18, 2010)

dkone said:


> Physically yes it can still pump gas, ...


Then in my opinion the intercom wiring is not functionally associtated.
...



> I ended up at 620 via exception #3 of 800.133:
> Exception No. 3: As permitted by 620.36.


I don't see the circuits in question as being "communications circuits as defined in Article 800. If they are not communications circuits, nothing in Article 800 applies.



> My original question about 620 was; does it only apply to the equipment listed in the title of article 600 or can it apply because 800.133 sent me there and because 620.36 specifically mentions "higher frequency communications circuits"?


Again, I don't see exception #3 applying to your application...in my opinion that exception only applies within the scope of Article 620 and your installation has nothing to do with the scope of Article 620.


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## dkone (May 20, 2016)

don_resqcapt19 said:


> Then in my opinion the intercom wiring is not functionally associtated.
> ...
> 
> I don't see the circuits in question as being "communications circuits as defined in Article 800. If they are not communications circuits, nothing in Article 800 applies.
> ...


I am not sure how you are doing the multi quotes so all my replies will be lumped together.

I have been talking about 2 different circuits other than the C1, one is a cat 5 cable for data and most certainly meets the article 800 definition. The second one is the intercom cable which is a C2 circuit.

The intercom as well as the data com component of the dispenser are integral components of the UL listed assembly that is the dispenser. I would have to politely disagree with your statement of not being functionally associated.

On a side note, I see that you are from IL. I just started design work on fueling project for a customer in Rockford City. Fun fact, the State Fire Marshall does not allow for indoor fueling. I am guessing they have amendments to NFPA 30A.

[2] – Article 800.2 Definitions

Communications Circuit. The circuit that extends voice, audio, video, data, interactive services, telegraph (except radio), outside wiring for fire alarm and burglar alarm from the communications utility to the customer's communications equipment up to and including terminal equipment such as a telephone, fax machine, or answering machine.


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## RePhase277 (Feb 5, 2008)

Can you put a box inside the dispenser to keep the two types of wiring seperate from the dispenser space, and branch out from there?


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## don_resqcapt19 (Jul 18, 2010)

dkone said:


> I am not sure how you are doing the multi quotes so all my replies will be lumped together.
> 
> I have been talking about 2 different circuits other than the C1, one is a cat 5 cable for data and most certainly meets the article 800 definition. The second one is the intercom cable which is a C2 circuit.


In my opinion the communications circuit as defined in Article 800 stops at the first item beyond the modem that is connected to the communications utility. After that device the conductors are Article 725 conductors. 



> The intercom as well as the data com component of the dispenser are integral components of the UL listed assembly that is the dispenser. I would have to politely disagree with your statement of not being functionally associated.


I have no problem with you ,disagreeing with me, however, it remains my opinion that if the dispenser can pump gas without the intercom, the intercom wiring is not functionally associated with the pump power circuit and cannot be in the same conduit no matter what types of wiring methods are used. 



> On a side note, I see that you are from IL. I just started design work on fueling project for a customer in Rockford City. Fun fact, the State Fire Marshall does not allow for indoor fueling. I am guessing they have amendments to NFPA 30A. ...


I have no idea....about the only NFPA document I know anything about is NFPA 70...the NEC.

Note that the only opinion that really counts is the one of the AHJ for the area where you are making the installation.


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## mitch65 (Mar 26, 2015)

would optical isolation on both ends of the cabling satisfy code? http://ca.blackbox.com/Store/Result... RS-485 Optical Isolator/Repeater``si_product


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