raceway mounted on the machine leg

[WadeCao]

Hi， everyone，

Want to investigate the option to mount raceway/cable tray on the legs of machines? So to avoid to installation on the roof or building structure. Is there a min distance that a cable tray/raceway(480v motor) has to be above the ground ？6 ft? How about distance to operator?

Just to save some cost and time to mount/hang everything on the ceiling.

Thanks

Added:

Thanks for all the promote reply! They are all good. Here I post a 3D picture of our production line. It includes conveyors(belt/chain), shredder, rotational screen, balers, etc. Pretty straight forward operation. Thinking about either put raceway/cable tray on the ground, Under the conveyors/equipment; or be mounted/hooked on the legs of the equipment. They will be along the machine side and no crossover (so to avoid any trip haz.) Largest motors are 160 kw/480v/3P.

Feel free to add your suggestions and comments.

 

[BrianPetersen]

Floor level is common. They're a tripping hazard, but for areas with low access, it may not matter. Or the machine can have its own floor deck with cables underneath, below the deck (which has removable floor panels for maintenance access).

About 2.2-2.5 metres up around the perimeter is common. Access doors etc can go underneath them.

Bear in mind that my world of welding and assembly robots may not be your world.

 

[JezNZ]

I assume this is NEC, what do your rules say?

My rules (IEC world) merely say that below 2m (in accessible area) is considered in need of greater mechanical protection, if you slap raceway covers on typically that requirement is met. But my rules give a great degree of freedom in determining or justifying what mechanical protection is required.

From a practical engineering viewpoint
- the risk of damage in normal or foreseeable abnormal operation needs to be considered and mitigated with appropriate mechanical protection.
- if the cables are going to operate at the maximum temperature allowed by certain grades of insulation (above 70degC), they may need to be protected from any physical contact for personnel safety reasons.

 

[Gr8blu]

WadeCao Keep in mind it is NOT RECOMMENDED to weld anything to the exterior of an electrical machine (for several reasons). One of these is the risk of damage to the machine itself - another is potential distortion of whatever electrical signal you're passing through the suspended cables because they are in close proximity to strong magnetic and electric fields.

Also keep in mind that doing things "cheap and easy" doesn't always result in "quality" at the end of the day, either.

Converting energy to motion for more than half a century

 

[BrianPetersen]

Didn't see anything about the original poster wanting to "weld anything to the exterior of an electrical machine". We have no idea what sort of equipment the original poster is wanting to do this with.

In MY world of industrial robots, the robot working area is surrounded by a perimeter fence. It's very common for a raceway to go around the top of the equipment at roughly the height of the top of that fence. This way, perimeter access doors and operator load stations can be underneath the raceway without the raceway being a tripping hazard on the floor, and you're not connecting power and air and cooling water and weld gas supply to something that is many many metres higher (i.e. the roof of the building) except at the incoming supply to the machine (which is often coming from the roof). The raceway is attached to the fence posts - no one is welding anything to the exterior of an electrical machine. Height of that fence is very commonly somewhere near 2.2 - 2.5 metres ... it has to be high enough for a perimeter access door to be fully underneath the raceway and with enough clearance for a tall person to walk through without banging their head, i.e. above the standard height of a doorway.

But that's my world. We have no idea what the original poster's world looks like, 'coz they haven't told us what it is.