Using Cable Shield as Ground Conductor??

[Bering C Sparky]

Hi,
First time posting to this site.
I work on a 345 ft Fishing Process Trawler, and we are going to be installing new electric winches to replace existing Hyd. winches.
I am just finishing my cable list to make an order and one question I asked back to the engineer at the winch company is "why do you only speck ground cable be run with the feeder cables from the distribution panel to the VFD cabinets and not from the VFD cabinets to the motors.
(220 kw motors 440vac 3ph)

His reply was the sheilding on the power cables is used as the ground wire. :jawdrop!!!!WHAT!!!!)
(We are using Lapp FD90CY single conductor cables run in parallel)
http://lapplimited.lappgroup.com/pr...s-applications-approved/oelflex-fd-90-cy.html

To borrow a phrase from Forest Gump "I am not a smart man" and I dont claim to be able to resite the NEC or other code, nor do I have an engineering degree but I simply do not believe that this is correct.

I have done some google'ing and brushed through 250 in NFPA70 but have not yet found anything to say specifically that this is right or wrong, but common sense alone says this cant be the correct way.
(I can find lots of articals that somewhat say you cant do this, like conductor size for PE, min size wire allowed to be paralleled, etc, but nothing specific about using the sheild as ground conductor.

I am going to install seperate grounding conductors anyway so I am not really worried what he says, but I am currious if anyone else knows if this is a standard practice or not.
If it is not does anyone know if it is even legal, where can I find something in writing to say this is right or wrong.
If this is a correct and legal use, I will eat my proverbial hat.
I will keep looking but I cant waste too much time on it.

Note: Winch Company and Engineer are not based in USA.

Thanks for any input.
BCS

 

[darekelec]

90.2
B) Not Covered. This Code does not cover the following 1) Installations in ships, watercraft other than floating buildings railway rolling stock, aircraft, or automotivevehicles other than mobile homes and recreational vehicles
FPN: Although the scope of this Code indicates that theCode does not cover installations in ships, portions of thisCode are incorporated by reference into Title 46, Code ofFederal Regulations, Parts 110-113.

 

[iwire]

I am going to install seperate grounding conductors anyway so I am not really worried what he says, but I am currious if anyone else knows if this is a standard practice or not.

If this was, or is covered by the NEC it would be a code violation to run a separate EGC outside of the cable containing the circuit conductors.

As far as using the shield as the EGC that could be NEC compliant if the size was correct.

 

[zbang]

If this was, or is covered by the NEC it would be a code violation to run a separate EGC outside of the cable containing the circuit conductors.

Unless I'm mistaken, that cable is shielded single conductor (maritime practice does lots of things differently). The spec sheet doesn't specify anything about the screen/shield, so using it for a fault return path seems dicey.