Machine facilitation?

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DubDub

Member
Location
Boise
Hello,

I really enjoy this forum. After trolling for some time, I have a question.

What are possible ways to facilitate a permanent piece of equipment that needs to occasionally (few / week) be rotated 0-90degrees (power would be off during rotation).The machine is attached to a 3rd party motorized rotator. I don?t think a plug / cord is possible since it is >50A service. We?d need about 20ft of ?flexible length? to drag through the rotation. Maybe a very flexible type of conduit with high strand count conductors to a junction / disconnect?

Thanks, Wayne
 

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mgookin

Senior Member
Location
Fort Myers, FL
Main thing is to avoid chafing.

We have a similar process which operates +/- 35 cycles per day traveling upwards 20' into a domed skylight and back down. Conductors run from the test station control area up to the ceiling (roof), over to the hoist, then back down to the floor.

We use cord (stranded conductors) for the main power going in and multiple stranded conductors for our control legs coming back out to an array of volt meters at the test station control area. It's effectively a homemade umbilical cord. It's been in operation about a year and works great.

No pinching, no touching, no rubbing and it should work well for a very long time. Looking at your drawing, maybe you want to feed power from overhead?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Main thing is to avoid chafing.

We have a similar process which operates +/- 35 cycles per day traveling upwards 20' into a domed skylight and back down. Conductors run from the test station control area up to the ceiling (roof), over to the hoist, then back down to the floor.

We use cord (stranded conductors) for the main power going in and multiple stranded conductors for our control legs coming back out to an array of volt meters at the test station control area. It's effectively a homemade umbilical cord. It's been in operation about a year and works great.

No pinching, no touching, no rubbing and it should work well for a very long time. Looking at your drawing, maybe you want to feed power from overhead?

From your drawing, run a permanent connection to somewhere at the base of the machine so that the flexible cord only has to go 10' in either direction and can be coiled up out of the way underneath between moves. If it is a really harsh environment, use flexible metal sheathed?

Do you have to be able to turn the power back on after the rotation (with the device still tipped to one side or the other)?
 

DubDub

Member
Location
Boise
Update for machine facilitation

Update for machine facilitation

From your drawing, run a permanent connection to somewhere at the base of the machine so that the flexible cord only has to go 10' in either direction and can be coiled up out of the way underneath between moves. If it is a really harsh environment, use flexible metal sheathed?

Do you have to be able to turn the power back on after the rotation (with the device still tipped to one side or the other)?


The machine would be 208VAC 3Phase 4W 90A.
We sometimes turn the power back on in the down position (older 50A systems). I?ve attached a jpg of the 2nd position.
In similar lower current applications (<50A) we?ve used a cord / plug and the cable management has not been a problem; the system rotates slowly and there is a technician running the process. The cable drags along the (smooth) floor about 6ft-8ft of dragging / uncoiling.

GoldDigger,

Your suggestion of using a cord to a permanent connection is what I had in mind. I was thinking the permanent connection would be directly into the factory panel / drop. According to the facilities folks they cannot tie a cord directly into the panel / drop (NEC).

Would code allow a cord from the machine to an intermediate junction box (that we supply) and they could then conduit into? Would a permanent cord from the machine to a junction box be acceptable code-wise as long as the factory connection is conduit to the junction box?

I assume an IEC 60309 plug with cord would be okay for code, other than they really do not like the perceived cost associated with adding IEC 60309 receptacles.

Flexible metal sheathed seems a little rigid compared to the cord option (I may be looking at the wrong type of flexible conduit.)

Thanks, DubDub
 

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GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I was thinking the permanent connection would be directly into the factory panel / drop. According to the facilities folks they cannot tie a cord directly into the panel / drop (NEC).

Would code allow a cord from the machine to an intermediate junction box (that we supply) and they could then conduit into? Would a permanent cord from the machine to a junction box be acceptable code-wise as long as the factory connection is conduit to the junction box?

I assume an IEC 60309 plug with cord would be okay for code, other than they really do not like the perceived cost associated with adding IEC 60309 receptacles.

Flexible metal sheathed seems a little rigid compared to the cord option (I may be looking at the wrong type of flexible conduit.)

Thanks, DubDub

The IEC socket with cover and plug would be OK for code, and since I could not find any NEMA standard locking cord/receptacle combinations for more than 60 amps it may be the best way to go. But there are other options too, including just running the cord into a junction box without using a plug and receptacle.

Depending on what the load is, you will probably have to kill power to the machine before connecting or disconnecting the cord.
Yes, you can mount the receptacle end to a junction box which is then wired by an NEC approved method back to the panel. Or you could mount the receptacle end next to the panel with a conduit nipple and box. But the shorter cord, not lying loose on the floor where people or machines could interact with it, would be better.
You would also have to provide any necessary strain relief and mounting hardware for the machine end of the cord of course.
 

Smart $

Esteemed Member
Location
Ohio
... I?ve attached a jpg of the 2nd position.
...
Consider securing the cord near the pivot point (two or more clamps perhaps to keep straight).

The cord on floor will not move... only the section between secured points. Also permits less flexible wiring methods to either side.

machinefacilitation.gif


Another option is to use a slip ring...
 
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