Standalone Storage Gas Tank

[swflelectric]

We have a company looking to install a above ground (under 500 gallons), double wall 120v driven gas tank(motor mounted above tank) for there Rental car business. We have a sub panel(6 space 60amp Single Phase) at that end of the parking lot that is around 50ft away from the container (container and panel located outside). Out of that panel there is only 2 GFCI outlets general purpose. We have a neutral kill 20amp 120v kill breaker installed for feeding the 120v pump and installed explosion proof fittings, and seal offs through out. We had a meeting with our inspector today and told us to install a mushroom style disconnect switch and make that entire panel shunt proof. The problem is how do we make this sub panel into a 60 amp main breaker shunt proof panel. I understand what he is saying but to even add the shunt at the main building it is over 400 ft away. Any ideas how we can comply with code and make this safe? Are there any products made specifically for this type of installation?

 

[mgookin]

Will the inspector let you install a sub panel next to that panel and have the shunt kill that entire subpanel?

 

[swflelectric]

I like it!!!! I will ask him today because he wasn't sure either yesterday. So with gas station installations you need to be able to shunt an entire panel when doing the installation? What should I know for future installations if we ever do another one?

 

[mgookin]

I'm assuming that existing panel does existing things, like lighting, vacuums for cleaning the cars, etc.

If you have a dedicated panel for the fuel service and you shunt that panel, I think you're good. That's why I suggested a sub panel. It needs to shunt the pump, computers, and everything providing any power to the fuel dispensing system and the immediate vicinity (fuel island lighting).

But I'm not your inspector. I suggest you call the electrical plans examiner for that jurisdiction and see what he says. You're going to need a drawing for your permit anyway so talk to the guy who's going to do the review. He's more into the books and the code than the inspector, and he's usually within earshot of the person at the fire marshal's office who will review your applications and plans too.

 

[kwired]

I don't think this is an NEC requirement, but very likely is a requirement of other codes. If you don't have anything except for the pump mentioned all you likely need an emergency stop for is that particular pump - probably located a minimum distance from the dispenser but still within plain sight so that power can be removed in case of emergency. A simple mushroom head (with contacts rated for the load) could probably directly interrupt the motor circuit. A commercial gas station is more complex as there is likely more than just a single pump involved, but a car rental place is likely just going to have a single tank and a single pump.

Most of the emergency stops I have seen in such a situation were required to be installed by insurance company more so than by electrical or fire inspectors.

 

[mgookin]

I don't think this is an NEC requirement, but very likely is a requirement of other codes. If you don't have anything except for the pump mentioned all you likely need an emergency stop for is that particular pump - probably located a minimum distance from the dispenser but still within plain sight so that power can be removed in case of emergency. A simple mushroom head (with contacts rated for the load) could probably directly interrupt the motor circuit. A commercial gas station is more complex as there is likely more than just a single pump involved, but a car rental place is likely just going to have a single tank and a single pump.

Most of the emergency stops I have seen in such a situation were required to be installed by insurance company more so than by electrical or fire inspectors.

In the 2012 edition NFPA 30A it's section 6.7
http://www.nfpa.org/catalog/TOC/30A-12-toc.html

The below images are from free access.

 

[kwired]

In the 2012 edition NFPA 30A it's section 6.7
http://www.nfpa.org/catalog/TOC/30A-12-toc.html

The below images are from free access.

View attachment 9260

View attachment 9261

Based on that information, I would say the fuel dispenser at the car rental place is likely "attended" and only requires disconnecting means to be accessible to the attendant, which is probably the same person doing the fueling in most cases.

We did not see many of these disconnects at gas stations around here until they started offering 24 hour gas if you paid at the pump. If gas is not sold without an attendant, or if it is not gas for sale to the general public these disconnects are not required.