Airfield CCR Circuits & Concrete Encased Conduit

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deb4523

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One of the projects I'm working on is adding new guidance signs at our army airfield. I am planning on adding the signs into the existing CCR circuits.

My question is do I need to worry about running the 1/C 5kV L-824 Type C cables from the existing circuit to the sign and back in different conduits or can I run them in the same one?

Also - slightly different topic, but same project. UFC 3-535-01 mentions encasing conduit under pavement in concrete. Does anyone know if the concrete has specific requirements - like the concrete pads for the signs are a minimum 3000psi, 6% air intrained... - or can I use a concrete slurry?

Thanks!
 
I guess breaking the question down to a more standard form is: Can I run a CCR cable to and from a piece of equipment in the same conduit without issues..?
 
Just going from memory now. But pretty sure you're going to need separate conduits. Although the ccr is designed to help eliminate interference. As for the above . You'll need to be below 36 inches of 4 inches of concrete on the runway.

Do you have the handbook? I know their are not a lot of options up their. Hope that helps.
 
Hi Buck! If you are referring to the NEC handbook, yes, I have the 2017 version.

Where did you get the 36" requirement from? In table 300.5 of the NEC, I see an 18" requirement..
 
Are you working with a FAA guy he should have your answers. He will inspect your work any way unless things have changed, Been since the first gulf war so?
 
do I need to worry about running the 1/C 5kV L-824 Type C cables from the existing circuit to the sign and back in different conduits or can I run them in the same one?
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They can be in the same conduit. It would be typical run a single 2" raceway to the nearest splice can or TW/RW fixture can.

Does anyone know if the concrete has specific requirements
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It does however I do not believe UFC 3-535-01 or UFC 3-260-01 will tell you. If this is a USACE project you will likely have a paragraph in spec section 26 56 20.00 10 that either clearly spells out the compressive strength or points to 03 30 00 for requirements of concrete used for encasement. If it is not a USACE project then UFC 3-550-01 says 3000lb. for encasement and 4000lb for pads.
 
deb4523 said:
One of the projects I'm working on is adding new guidance signs at our army airfield. I am planning on adding the signs into the existing CCR circuits.
My question is do I need to worry about running the 1/C 5kV L-824 Type C cables from the existing circuit to the sign and back in different conduits or can I run them in the same one?
Also - slightly different topic, but same project. UFC 3-535-01 mentions encasing conduit under pavement in concrete. Does anyone know if the concrete has specific requirements - like the concrete pads for the signs are a minimum 3000psi, 6% air intrained... - or can I use a concrete slurry?

Thanks!
Click to expand...

Airfields and military projects are covered by the Engineering Guidelines set by MIL SPECS (Mil Std 810F) along with FAA. Different branches of military ie Navy, Marine, Air Force and Army have different Engineering Personnel to handle their projects.
Depending on the branch you are engaged in, you need to consult (if you haven't done so) the OICC Naval Services or MIL-Com (DOD) for Airforce and Army.

They are bound to MIL STD 810 F guidelines but not civilian NEC. They can use (NEC) if the design engineer wishes to adopt it but he is not required.

Because of longer runs, those XLPE Cables with cross-linked polyethylene insulation can either be pulled in conduit or direct burial. Even though these cables are rugged, direct burial is preferred to eliminate subjecting these cables to abrasion and pulling tensions that will exceed sidewall bearing pressure limits if pulled in conduits.

As for compression test for concrete, this is spelled out according to MIL Specs.

I suggest you get a copy of Advisory Circular (AC) Publication for free.

Write to: U. S. Department of Transportation
Subsequent Distribution Office
Ardmore East Business Center
33419 Q 75th Ave.
Landover MD 20785

This is what I dug up but I don't have their website.

Good Luck
 
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