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Need clarification on 514.11 (Circuit Disconnects for Fuel Dispensing Facilites)

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    Need clarification on 514.11 (Circuit Disconnects for Fuel Dispensing Facilites)

    Article 514.11(A) states:

    514.11 Circuit Disconnects.
    (A) General.
    Each circuit leading to or through dispensing
    equipment, including equipment for remote pumping systems,
    shall be provided with a clearly identified and readily
    accessible switch or other acceptable means, located remote
    from the dispensing devices, to disconnect simultaneously
    from the source of supply, all conductors of the circuits,
    including the grounded conductor, if any.
    Single-pole breakers utilizing handle ties shall not be
    permitted.
    Use of the terms "switch" (singular) and "disconnect simultaneously" it appears that it must be one switch that disconnects all power. So what if there are more than two circuits that need to be disconnected. The enclosed emergency stop switches I've found can accommodate no more than two stacked DPST switches. Since both the hot & neutral legs must be broken, that's one DPST switch per circuit, thus a maximum of two circuits.

    A second question I have is regarding the circuits that are affected by 514.11(A). Our fleet dispenser requires two circuits (one 230VAC circuit for pump motors and one 115VAC circuit for electronic controls, solenoids, & dispenser internal lighting). Outside the dispenser, we are installing hose reels with power rewind (115VAC). Would these hose reels be considered on a "circuit leading to or through dispensing equipment"?

    #2
    I'll take a stab at it.

    So the way I understand it is, when the code says "disconnect simultaneously" it is referring both the ungrounded and grounded (hot&neutral) conductors of each circuit. It would basically be a switched neutral breaker for a 120v circuit, and a two pole breaker for a 240v circuit.

    The way I normally use emergency stop button are in conjunction with a shunt trip breaker which powers the entire fueling panel. If the entire panel can not be powered down in the case of an emergency, then one case use the e-stop in conjunction with contactors for the circuits within that classified area. Should be a NC contact for contactors and NO for the shunt option if I'm thinking correctly.

    In regards to the second question, the way I understand it is they all need to be shut down. Hose reel, disp lighting, pump motor, etc. this can be done with one of the above methods. I myself like using shunt panels. No problematic contactors in the future.

    Comment


      #3
      The few I have worked on used a six pole switch as the means to disconnect all circuits to each pump individually.

      Comment


        #4
        Originally posted by Jon456 View Post
        Article 514.11(A) states:



        Use of the terms "switch" (singular) and "disconnect simultaneously" it appears that it must be one switch that disconnects all power. So what if there are more than two circuits that need to be disconnected. The enclosed emergency stop switches I've found can accommodate no more than two stacked DPST switches. Since both the hot & neutral legs must be broken, that's one DPST switch per circuit, thus a maximum of two circuits.

        A second question I have is regarding the circuits that are affected by 514.11(A). Our fleet dispenser requires two circuits (one 230VAC circuit for pump motors and one 115VAC circuit for electronic controls, solenoids, & dispenser internal lighting). Outside the dispenser, we are installing hose reels with power rewind (115VAC). Would these hose reels be considered on a "circuit leading to or through dispensing equipment"?
        Remember that that you must meet the requirements of both 514.11 and 514.13. This can get complicated if you have more than just power circuits involved such as a card reader, audio, etc. In most cases today, the only way to accomplish this and be compliant is to use a listed product that is made for this purpose. All the petroleum equipment makers have stuff available that is made for this purpose.
        The old school methods of shunt trip breakers, contactors, etc cannot be used for a variety of reasons.

        Comment


          #5
          Sq D makes a switch where you can add contacts to do power, and then 2 wire loop for pump data, card reader and intercom. Cat 5 which is becoming really common in pumps and more so in the future for EMV card readers is a problem.
          http://www.schneider-electric.us/en/...er-disconnect/

          Power Integrity makes a box that handles Pump loops, card readers, intercom and Cat 5 .
          http://www.powerintegritycorp.com/in...age-disconnect.

          I generally use NO relays for all 120v loads to switch hot and neutral, Estop holding relays closed until pushed. Sometimes I use 3 pole contactor and switch sub panel. Making sure fire suppression and other items that need to stay on are not in that panel

          Not sure how one can use a shunt trip as that leaves neutrals still connected unless all your loads are 208-240v?

          Comment


            #6
            Yes. Our petroleum people always supply the low voltage equipment for credit card/pump control. They usually have little disconnect switches inside them to turn off each disp individually.

            As as for the shunt trip integration, can one not use a 3 phase shunt breaker and use one pole for disconnecting the neutral and the other two for the line voltage phases?

            Comment


              #7
              Wouldn't a 3 phase shunt trip have ungrounded conductors on all 3 poles? I don't know if they make a 4 pole, 3 hots and 1 grounded in a shunt trip but I doubt it. I know they make 3 pole, 2 hots and switched neutral but it isn't a shunt trip.

              Comment


                #8
                Originally posted by wallyworld View Post
                Wouldn't a 3 phase shunt trip have ungrounded conductors on all 3 poles? I don't know if they make a 4 pole, 3 hots and 1 grounded in a shunt trip but I doubt it. I know they make 3 pole, 2 hots and switched neutral but it isn't a shunt trip.
                I would imagine someone makes a 4 pole shunt breaker, but probably ridiculously expensive. We normally have single phase 240v submersible or gravity fed pumps. Where we do have 3 phase submersibles, they are powered through a Mag VFC by FE Petro, normally, and if you interrupt the dispenser hook signal, there will not be any power present out there. So basically the e-stop is going to shut down the panel powering the dispensers, and therefore there will be no disp hook power. If you just need to do maintenance on the submersible, one can just use the breaker for power interruption.

                Comment


                  #9
                  Just to be clear, "to or through dispensing equipment" does not include lighting or CCTV mounted on the canopy above the dispenser (above the classified area), correct?

                  Comment


                    #10
                    I think the best way to solve this problem is with a shunt-trip breaker upstream of the sub-panel that feeds the dispenser. But that means the shunt-trip breaker must disconnect two hots and the neutral. Is there a special switched-neutral, 2-pole shunt-trip breaker? Or do I simply use a three-pole, lug-style shunt-trip breaker and use one of the poles for the neutral?

                    Comment


                      #11
                      I was thinking about this post again, and I don't believe there is anything that says when the emergency stop button is pressed, that it needs to disconnect the neutral also. It does say that it needs to have a means to disconnect the neutral, along with the hots, and low voltage. This is for maintenance, not under an emergency situation. Please correct me if I am wrong.

                      Comment


                        #12
                        Originally posted by Dr Duke View Post
                        I was thinking about this post again, and I don't believe there is anything that says when the emergency stop button is pressed, that it needs to disconnect the neutral also. It does say that it needs to have a means to disconnect the neutral, along with the hots, and low voltage. This is for maintenance, not under an emergency situation. Please correct me if I am wrong.
                        OK. It's an emergency requirement. If it were only for maintenance, it would be a general requirement throughout hazardous locations - at least for Division 1.

                        Basically, in an emergency all conductors to a dispenser must be isolated. The theory is there is a potential "surge" backfeed through the grounded conductor which could possibly arc in the Division 1 location. (Remember, the possibility, not necessarily the inevitability, of an arc is all that matters in Division 1.)

                        Where you are right is the pushbutton itself need only be the actuator for the device(s) that actually perform the "means" for isolating the conductors.

                        It should be noted this is a residual philosophy from the NFPA 30A Technical Committee and its predecessors and has been for many decades. Code Making Panel 14 has little control of the content of Article 514. They can only make sure it is not in direct conflict with the rest of Articles 500 to 504. See Sections 510.1 and 501.2.
                        [COLOR=black]"Bob"[/COLOR]
                        Robert B. Alexander, P.E.
                        Answers based on 2017 NEC unless otherwise noted.

                        Comment


                          #13
                          A little late

                          A little late to this party, but I HATE shunt trip breakers for E-stops. It's a fail closed device and IMO should not be allowed for this purpose.

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