# Service intervals of truss motors



## Madhair (Nov 15, 2012)

Hi guys. The venue where I'm working has trusses which are suspended from the ceiling with the motors mounted on the truss. The trusses are always hung. Never derigged as they're our only way to rig the lamps. Just wondering how often should the motors be serviced?

Thanks
Shane


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## Footer (Nov 15, 2012)

Yearly. They should be brought down and services by a certified tech. Chains should also be oiled.

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## tyler.martin (Nov 15, 2012)

My trusses are hung from motors as well. We service ours yearly, but one thing that we do is when we get into show mode, we put in steel drifts to take the weight, but leave the motors connected as safetys. Are motors designed to hold a load statically for a long period of time?


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## derekleffew (Nov 15, 2012)

http://www.controlbooth.com/forums/scenery-props-rigging/20990-chain-hoists-permanent-install.html


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## porkchop (Nov 16, 2012)

I say yearly as well. Unless you have a whole ton of chain hoists a good tech should be able to get through all of them in a day or two.


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## MPowers (Nov 16, 2012)

Yearly if your use is seldom, i.e. 1 to 10 trips up and down a month or less. 10 to 30 ( one a day max) then inspect every 6 months, more than that *or* if many or most loads are close to maximum, every 3 months. The last condition is unlikely in the entertainment industry but "could happen"! 

The above is our company policy and our advice to clients. It is a compilation of the recommendations of StageMaker, CM and Chain master maintenance manuals, and over 200 combined years of rigging experience of our rigging techs. 

We don't have any clients with "permanently installed, load bearing hoists". We do have some with the hoists mounted in a permanent manner, but the loads are per event. The hoists are mounted above suspended ceilings or similar, and per event rigging would be excessively difficult and time consuming. The "permanent" mounting allows the chain hooks to be run in on a moments notice. We do bring them down and do a complete service check and inspection annually. If we are asked to install a permanent load using chain hoists, we will recommend other solutions such as Line shaft hoists, Package hoists (PowerLifts, Vortek, Prodigy, et. al.) Motorized Clew winch, and plain drum hoists. Each has it's niche and in that niche is the best choice. In our opinion, chain hoists for permanent loads are acceptable but usually not the best choice. 

At this point in time there is no specific (USA) code or regulation that regulates inspection time frames. If we, as an industry, maintain a diligent and encompassing practice of maintenance, record keeping and safety, there will never be a reason for any government entity to step in and regulate the use of chain hoists. On the other hand, in Europe there is a great deal of regulation and they have a sterling safety record (AFAIK).


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## danTt (Nov 17, 2012)

tyler.martin said:


> My trusses are hung from motors as well. We service ours yearly, but one thing that we do is when we get into show mode, we put in steel drifts to take the weight, but leave the motors connected as safetys. Are motors designed to hold a load statically for a long period of time?



I'd personally be more concerned with the motors taking a shock load if the steel failed than I would leaving the load hanging from the motors.


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## tyler.martin (Nov 17, 2012)

The motors aren't completely slacked off, there is still some weight being held by the motor, if the steel did fail, the shock load would negligible.


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## mstaylor (Nov 21, 2012)

Generally when you hard safety trusses you take it to trim, attach the hard safety and then lower the hoist back down until there is weight on the steel. The motor slack is as little as possible, a link or two.


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