Flexible cord installed outdoors

[mgoth]

Hello to all, new to forum.

I just changed jobs and am suddenly the resident expert on the NEC since I am the only EE (I just bought the 2002 NEC handbook).

My new company makes powered awnings for home and RV use and I am trying to educate them on how to do things electrically correct. They want to use SO cord from a 12VDC motor on the awning to a power converter to be installed inside the home. They want to run the SO cord along the exterior of the home to a junction box where it can be spliced to the 12VDC coming from the power converter inside the home. However, 400.8(4) states that flexible cord shall not be used where attached to building surfaces. Does this mean that my application meets code as long as I don't use any staples to route the wire???

Any help or suggestions would be greatly appreciated.

Thanks,
Mark

 

[tom baker]

Re: Flexible cord installed outdoors

If this is a limited energy circuit, then ART 725 modifies the rules in Chapters 1-4, see Section 90.3 Once you determine what class the limite enrgy is, then you can review the rules.

Congratulations on your do it right attitude.

 

[hurk27]

Re: Flexible cord installed outdoors

This sounds like a class 1 circuit. (less than 30 volts/less than 1000 V/A.
If it is it would have to comply with article 400.8.
and that means it can't be attached to the building, run through walls or run inside of the walls.
To me it sounds like the only thing that would be possible is to combine the power supply on the awning and allow a power cord to plug into the outside receptacle and use a wireless remote to have control from inside of the house/RV.
Maybe you could get a UL listing for away to do this then the NEC wouldn't cover it.

 

[jrdsg]

Re: Flexible cord installed outdoors

you don't indicate the amperage or the wire gauge involved, but...

we often install similar 12-24V power circuits using flexible liquid-tight conduit and plastic boxes and fittings. the flex can be mounted to soffits or other aesthetically acceptible locations using typical aluminum or galvanized EMT clips.

the circuit needs to be fused, of course.

this sounds alot like those little low-voltage garden lighting circuits.

 

[hbiss]

Re: Flexible cord installed outdoors

Maybe now that they have you on board they will realize the problems a 12VDC motor cause in such an application. As you know, you can't get something for nothing- as the voltage decreases the current increases meaning you need a large wire size to supply the load. This is something you seem to overlook.

Maybe because these will be used on an RV with a 12 VDC electrical system they think a 12 VDC motor is a good idea. Most RV's also have a generator and a 120VAC system. Your other market, homes, obviously have a source of 120VAC.

If it were me I would push them to change the motor to 120VAC. This would solve a multitude of problems in supplying power to your product. I'll bet it would also save your company alot of money because you will no longer have to supply those transformer/rectifiers.