OT: Conductor bus system

Hey guys, I apologize for being very OT with this, but I am posting this here for a reason. Yall have a LOT of experience with all kinds of different machines. And that may just help answer my question.

I am trying to come up with something similar to a ductobar system that are commonly used on gantry cranes to supply power to them. However I need something much smaller. I only need to supply 24VDC,5A to something that moves about 30 feet back and forth.

Has anyone seen some interesting solutions in their travels that may help me out?

Thanks

Depending on the application, a sliding cable on a messenger wire or a wire on a spring-loaded self-retracting reel might work.

As already said two wires in air tensioned to minimize sag and to maintain distance between the two. Then one wire on a ring sliding down each horizontal wire to feed machine. Major issue here is ensuring someone does not clothesline himself ie walk into the wire.

Reel is great if you mount on the carriage or whatever it is. Ensure you have large enough motor to overcome machine load ie rolling resisttance and the force of the spring in the reel.

Dan Bentler

I would be concerned about the longevity of a self retracting reel. This will run up and down a rod, about 2000 times a day. Plus speed may be an issue. At certain times during the process it will have to run pretty fast, perhaps faster than the reel can retract.

Something along the lines of a ductobar system would be great, if it were just a whole lot more compact

mutabi said:

I would be concerned about the longevity of a self retracting reel. This will run up and down a rod, about 2000 times a day. Plus speed may be an issue. At certain times during the process it will have to run pretty fast, perhaps faster than the reel can retract. .


Something along the lines of a ductobar system would be great, if it were just a whole lot more compact

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Horizontal overhead catenary - just like they do with electric buses here in Seattle. Worked well for 70 years and still works

IF vertical use a two conductor cord and let the free end dangle below the machine - just like they do in elevators.

Dan Bentler

At my previous employer we had a linear actuator that transported a 480vac 3-phase cutter motor back and forth about 12 feet. It has an enclosed bus bar system mounted above the actuator ballscrew with four bus bars in it with spring loaded contacts. The motor was connected to it via those contacts. I don't recall who made the thing. I will think about it and if I can come up with a mfg. I will reply back.

another option is an Igus trac http://cableorganizer.com/igus/

OkiePC said:

At my previous employer we had a linear actuator that transported a 480vac 3-phase cutter motor back and forth about 12 feet. It has an enclosed bus bar system mounted above the actuator ballscrew with four bus bars in it with spring loaded contacts. The motor was connected to it via those contacts. I don't recall who made the thing. I will think about it and if I can come up with a mfg. I will reply back.

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Should be able to get any crane outfit or good industrial control outfit to supply this stuff. I thought he wanted inexpensive

Dan Bentler

Thanks guys, Yes inexpensive is always good. I will be contacting a crane manufacturer. We use duct-o-bar systems quite a bit in our plant, and they work great, but are just way too bulky for this application. Browsing their websites, they just seem to deal with crane applications (50A is the minimum rating), and their collector shoes are just waaaay too bulky.

The closest thing I have found so far, is this http://www.conductix.us/products/conductor-rail/811-series/

The Igus Trac that was mentioned just wouldn't hold up. We use some of those as well, and are useful in a lot of applications..just not this one. Thanks for the suggestion though!

Do you have other power sources connected to your equipment? If you do, it may make more sense to bring in one power source and create your other local systems on the part that moves?
i.e. bring in 480 VAC as general power for motors and other equipment and than use a three phase power supply to derive your 24 VDC system locally.

Just curious as to why the igus or a similar system would not work if properly installed.
They are standard items on high speed metal forming machines.
I also maintain overhead crane systems, and the buzzbar/collector method on them is needed for the very long travel lengths, but require frequent maintenance.
Just for reference, I have seen igus tracks, with collector trays and proper cabling work over millions of cycles, at speeds up to 30 ft/s, accelerations up to 20 ft/s².
I am presuming the movement is horizontal, so any system will need to have very good guidance - linear rod or rail. No power delivery system will hold up without smooth, positive guiding.

I have seen the igus system used on a high speed shear which traveled back and forth about 30', 14 complete cycles per minute. It carried several sensor cables and two air lines. It works great until it develops a tiny crack and then it trashes everything before you can slam the e-stop button. And if you don't stock enough parts to fully repair every damaged piece, it will explode again in short order.

I still can't remember the brand name of the linear power rails we used on a 480vac three phase machine, but it was not exactly maintenance free either. It was on a shorter axis and moving much slower. When it failed, the motor on the carriage might get cooked due to single phasing but the OL relay would usually trip first and the repairs were minimal...usually correcting alignment and replacing the contacts.

The best system we had on a different shear was a southern engineered "coily cord" hanging from above on a long extension spring to hold the slack up. Those almost never gave us trouble, and when they did, it was usually just a matter of chopping off a few inches due to the cable jacket wearing through the CGB and re-terminate.

Yeah, I have seen "c-track" or "energy chain" blow up also, usually from mechanical misalignment, applying force perpendicular to the chain or causing the chain not to collect in its tray and bind up.
With enough room below and a decent trough to "catch" the cable, the igus style chain can be skipped, a good strain relief at the moving end helps a lot.