Chain Hoists as permanent install?

If it needs to be accessible at floor level, hang it with some well maintained CMs and relax.

When CM hoists first crossed over from industrial to stage use, the standard (industrial) way to hang them was motor up, chain hook down. Riggers didn't like pulling 1 ton hoists up to the grid (who could blame them?) but the relay in a CM wasn't designed to operate "upside down". In order to hang them chain hook up, they used to put rubber bands around the relays (not very bright), or turn the relay 180 degrees and remount it inside of the motor (better). I don't remember when CM updated the relay so the hoist could run in any position, but it was more than 10 years ago. Unless you are using older gear, or another manufacturer, they will run fine either way.

Rigging chain hook down will look cleaner, but getting the motor down for maintenance will be a problem. Rigging chain hook up is less labor, and easier to maintain, but requires more cable and is not as clean looking. Your call.

As for dead hanging the load as a safety, there may be local code that requires it, but from your description the load will be static other than when the motors are running. In my opinion, while anything is possible, I've been trusting CM hoists with my life for over 30 years, and have never had a reason to give it a second thought. It is my experience that a properly maintained CM will hold anything it can lift, for as long as you want it to.

If your rig uses Spansets anywhere in a load bearing capacity, you will need steel safeties in those positions, because, as amazing as they are, Spansets don't do well in a fire.

Be sure that you can and do, disconnect power from the motor power distribution system when the motors are not being run. While I've never seen a CM fail to hold it's load, I have seen motors start running on their own, without anyone near the stage, because of problems in the power/control system. This can be dangerous, and expensive. just unplug it after it's up.

Hope this helped,
LtheC
 

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