Fuel Tanks Circuitry

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tryinghard

tryinghard

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California
This picture is gas & diesel fuel tanks, I understanding these to be C1/D1 even by the manufacture of the tanks.

If I run a new fuel pump circuit and a signal circuit surface from center kiosk to a new tank (#6) at far right will these conduits/J-boxes/condulets need to be explosion proof application Article 514 for both power and signal?

Will I need to install conduit seals at intervals along these conduit runs, 501.15?

FuelTanks.jpg
 
If I run a new fuel pump circuit and a signal circuit surface from center kiosk to a new tank (#6) at far right will these conduits/J-boxes/condulets need to be explosion proof application Article 514 for both power and signal?
Click to expand...

The power circuit will need to be x-proof. If the 'signal circuit' is intrinsically safe then article 504 will apply (and you won't need to be x-proof). You will still need to seal the conduits (not necessarily with "chico" type material).
 
For the pump circuit (power) I would seal at the exit of the kiosk but then this circuit runs surface across the top of tanks #4, 5 & 6 to a new dispenser at 6.

In reality it currently leaves the kiosk UG with a seal then rises up at the first post to the right to another seal and existing j-box, there is room for the new circuit after I up-size the existing J-box. From this explosion proof j-box I will then run it surface above the tanks to its destination as a C1/D1, if I am within 10' of the tanks (and I will be) - I am not sure about this 10' area I'm just going to install it anyway :-?.

The manufacture information states "All electrical devices used with or located within twenty (20) feet of the ConVault? tank should conform to NFPA 70 Hazardous Locations. All electric conduits and wiring connected to the tank should be explosion proof and in strict accordance with NEC Class-1, Division 1 or other local standards whichever is stricter."

  • [1]When I see Figure 514.3 it confuses me, is the area outside 18" unclassified meaning non-explosion proof is compliant? (The '05' handbook includes an Exhibit 514.1 also)

    [2]Regarding the above ground tanks the manufacture directs me to install in "strict accordance with NEC". I notice 515.3 and handbook Exhibit 515.7, is the area outside the 10' unclassified meaning non-explosion proof is compliant? Does this section even apply to my application?
 
tryinghard said:
  • [1]When I see Figure 514.3 it confuses me, is the area outside 18" unclassified meaning non-explosion proof is compliant? (The '05' handbook includes an Exhibit 514.1 also)
Click to expand...
  • Yes the area above the 18" and farther than 18" from the pump/dispenser is not classified
    [2]Regarding the above ground tanks the manufacture directs me to install in "strict accordance with NEC". I notice 515.3 and handbook Exhibit 515.7, is the area outside the 10' unclassified meaning non-explosion proof is compliant? Does this section even apply to my application?
    Click to expand...
I would say 515.3 is good guidence
 
Currently there is an existing sub panel inside the kiosk that is explosion proof. This area is over 3' from any dispenser with this it just adds to my confusion.
 
Basically you need to remember that both Articles 514 and 515 apply. The location around the dispenser is classified by Art 514 and the location around the tanks is classified by 514. Any common points assume both classifications. (They will still probably be the same just the envelope will change a bit.)

Once the classifications are defined then installation is fairly straight-forward under Art 501; however, it is important to note that both Articles 514 and 515 have unique requirements underground and above Class I that are beyond Article 501.

The critical issue is getting the electrical area classifications documented properly in the fist place. [Section 500.4(A)]
 
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