a question about installation of a conveyor.....

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Fulthrotl

Fulthrotl

~Autocorrect is My Worst Enema.~
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HB, CA (19 Hrs. 22 Min. from Winged Horses)
Occupation
E
i have a stacking conveyor to hook up.
it's in a permanent location with regard to the
pivot point, but will swing in about a 270 degree arc,
as it telescopes and runs thru a program to lay aggregate
in windrows... so it'll be slowly rotating constantly, back and forth.

power requirements will dictate a 500MCM-3 conductor cord -w- ground
on 480 volts. power will be fed underground. 400 amp supply.

i'm trying to devise a cable strategy that will allow the cord to live a long
and protected life, as when there is loose material around the pivot on
the conveyor, the common thing to do is clean it out with a rubber tired
loader. and if there is 2' of gravel over this cord so you can't see it, you know
what will happen.

anyone got any experience with feeding a stacker like this? i could use suggestions.

 
I don't see how the NEC would allow putting a cord in an area subject to being buried only to be cleaned out by a loader.
 
I would be inclined to sleeve the cord at the base where it pivots. maybe in a 6 inch pipe that goes up several feet so the gravel is on the outside of the pipe and not on the cord.
 
iwire said:
I don't see how the NEC would allow putting a cord in an area subject to being buried only to be cleaned out by a loader.
Click to expand...

i don't either. i need to get some details on where the pivot pin is located at, and how much elevated it is.
i was thinking of a 4" GRC encased in a sonotube with a hubbell strain relief on top and a cable management
device to keep the cable suspended. this way, the conduit is encased and protected, and the cable is off the ground.
there are straight line trolleys that will do that, but i need something circular, so the cable can pay out as the thing
turns clockwise and returns, and the cable stays off the ground. i suppose i can fabricate a curved trolly and make
that work, but it's going to be an expensive thing to do in time and material.

then when they need to muck it out, they can turn the stacker to full cable extension, with the cable up high, and clean it all out
with a loader. the conduit will be encased in concrete till it gets to a 3' x 4' underground pull box, with a traffic rated cover.

there, it will make up in a junction box to a pair of 500 mcm conductors, for the voltage drop.

spoke with the manufacturer, and he said most of the time, they feed it overhead so the cable is suspended.
the only way i can see doing that is with the traverse conveyor carrying a pair of 4" GRC conduits up to a junction
box near the head of the conveyor, and transitioning to cord at that point, with a strain relief on both ends.

but no matter where you put the drop at, at some point it's going to cross over the aggregate stream dumping into the
stacker, and i don't see that as a good thing, either.

so i figured maybe someone on here has done something similar......
 
Fulthrotl said:
i have a stacking conveyor to hook up.
it's in a permanent location with regard to the
pivot point, but will swing in about a 270 degree arc,
as it telescopes and runs thru a program to lay aggregate
in windrows... so it'll be slowly rotating constantly, back and forth.

power requirements will dictate a 500MCM-3 conductor cord -w- ground
on 480 volts. power will be fed underground. 400 amp supply.

i'm trying to devise a cable strategy that will allow the cord to live a long
and protected life, as when there is loose material around the pivot on
the conveyor, the common thing to do is clean it out with a rubber tired
loader. and if there is 2' of gravel over this cord so you can't see it, you know
what will happen.

anyone got any experience with feeding a stacker like this? i could use suggestions.
Click to expand...
What the heck! I have seen these things in gravel pits and batch plants.
None of them ever needed 500MCM. They make 500MCM cord?!

At any rate all I have ever seen at gravel pits is SO cords run everywhere.
NEC be damned. MSHA was the only rule and the electrical work I have
seen that passed an MSHA inspection looked worse than the electrical
I saw during my trips to Mexico.

I don't recall a problem with the cords getting buried tough.
Seemed easy enough to route them up, on, or over something to get them out of the way.
None of them were 500MCM though.
 
ActionDave said:
What the heck! I have seen these things in gravel pits and batch plants.
None of them ever needed 500MCM. They make 500MCM cord?!

At any rate all I have ever seen at gravel pits is SO cords run everywhere.
NEC be damned. MSHA was the only rule and the electrical work I have
seen that passed an MSHA inspection looked worse than the electrical
I saw during my trips to Mexico.

I don't recall a problem with the cords getting buried tough.
Seemed easy enough to route them up, on, or over something to get them out of the way.
None of them were 500MCM though.
Click to expand...

this one will be... main motor on the conveyor is 100 HP.
there are two of those motors, and a number of additional ones,
adding up to about 350 amps of 480 on the stacker alone.

looking at about 600 amps on all the conveyors when they are up and running.

500MCM-3 is above $50 a foot, but yeah, it's available.
i haven't priced the kellums grips yet... i don't even want to
think what a 4" kellums grip costs. bet they are $400 each. or more.
hm. i looked. $589 each on the web.

plowed up my first snake on this in calcing the service needs. seems
all of the starters are across the line. no vfd's or soft starts. the POCO
won't even approve the service upgrade without soft starts. dumping
these on line, especially if loaded with rock will cause a severe power
dip.... so as the plan contacts reality, some adjustments will be made.

i'm gonna surf mcmaster-carr for some type of trollys that i can put
on a curving rack to hold this thing off the ground. i can fabricate anything
i need, all i really need is the trollys. i'm thinking a ball one in between
two concentric 1" pipes, with hangers holding the pipes from above,
around the base of the pivot.

off to the bar napkin design stage of the program.
 
Fulthrotl said:
off to the bar napkin design stage of the program.
Click to expand...
500MCM cord. I'm gonna stop thinking about that, my back is getting sympathy pains.

I have been on a lot of projects where what was on the napkin was was the total design.

Been on a couple of projects with stacks of engineered drawings.

Looking back, the ones with the stacks of drawings didn't go any smoother than the ones with a napkin tacked up on the dash of the work truck.

Buenos Suerte. Post some pics.
 
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