Grounding above ground fuel tanks

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wormy

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I wired up a 1000 gallon above ground gasoline tank today. Its feed is a 208 volt 20a circuit fed from a sub-panel. The tank is grounded with a #12 ground wire from the panel. The mfg is saying I also need to drive a ground rod at the tank and ground to it also. Is this against code as the tank is already grounded from the electric circuit from the building?
 
wormy said:
I wired up a 1000 gallon above ground gasoline tank today. Its feed is a 208 volt 20a circuit fed from a sub-panel. The tank is grounded with a #12 ground wire from the panel. The mfg is saying I also need to drive a ground rod at the tank and ground to it also. Is this against code as the tank is already grounded from the electric circuit from the building?
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I believe that is a supplemental ground rod per NEC say 250.53(E)

But, there could be several other codes that apply here, also, is it consider a hazardous location??
 
wormy said:
I wired up a 1000 gallon above ground gasoline tank today. Its feed is a 208 volt 20a circuit fed from a sub-panel. The tank is grounded with a #12 ground wire from the panel. The mfg is saying I also need to drive a ground rod at the tank and ground to it also. Is this against code as the tank is already grounded from the electric circuit from the building?
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Additional connections of a grounding conductor to earth are not a problem and not a code violation. Additional connections of the grounded conductor to earth are a problem and a code violation.
 
Should be no problem with an additional ground. I would not ignore the manufacturer's recommendations. Static electricity is a big issue with above ground fuel tanks and grounding is critical. Redundancy is sometimes a good thing - and grounding is a good example.
 
I have wired pumps for bulk fuel facilities where fuel is transfered from bulk tanks to delivery trucks in the past year. Both of the places I worked at I installed EGC to pumps and other equipment as usual to comply with NEC.

The tank and piping contractors installed bonding jumpers between just about every pipe and structural metal you can think of as well as to a ground rod. Many of these items were already inherently bonded through piping and supports but they ran a #6 bare between and landed it in pipe grounding clamps anyway. Also attached to this was a flexible conductor with a clamp attached to the end to connect to the truck before loading/unloading.

I'm sure this was all intended for equalizing effects of static electricity. You don't want to put nozzle into truck and have an arc from a static discharge ignite fuel vapors.
 
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