Bleacher Motors

[Jraef]

I think the solution may well be that the manufacturer has it covered.

The installation instructions normally tells the electrician exactly what he has to provide. If they say just provide a 40A circuit, the manufacturer probably has the overload requirement covered somehow.

I just had a project that included telescoping bleachers, and the instructions just said to provide a circuit with a disconnect. (The disconnect was similar to the one someone else mentioned -behind the bleachers.)

I just dug into the spec. for that unit, and I found the control panel has a frequency inverter and overload protection for the motors. I'll bet the OP's is similar.

I don't disagree that this is more likely the case than not, but as the EC, the responsibility for making sure that all code requirements are met at the installation is YOURS, not the mfrs. Ask any lawyer.

So should he dig deeper like you did and make absolutely sure this is already covered? Yes, you are right on that.

If it isn't, does the fact that the mfr didn't tell him that absolve him of responsibility? No.

Does the lack of, or poor quality of, information from mfrs result in duplicated efforts on behalf of the EC just to be sure? Absolutely, happens all the time, but it's the only way to ensure safety sometimes.

 

[RogerD]

I definitely appreciate all the input, trust me the digging has been done, I'm currently reaching out to the manufacturer for additional info. (ie forgot to ship a CP)

No control panel of any sort was supplied. There's 5 motors operating in sync to open and close telescoping bleachers. Overall length of the bleachers is about 80'.
Individual switches are mounted to each motor as a local disconnect.

It's a single point for connection and the motors are operated by a single, hand operated forward and reverse controller, the controller itself doesn't specify if it's contains thermal protection or not, I'm guessing no. Guess we'll see when the manufacturer responds.

Thanks again

 

[USMC1302]

Sounds typical. Where I am from if this is new work, the equipment vendor has the EC provide the power and make the connections. Pendant receptacle mounted in a box under the first row riser that flips up. Wiring is "festooned" for my lack of knowledge on a better descriptor, to the control panel via the bleacher supporting structure. Not sure that is code compliant, but all I have ever seen done. Please do consider where that contol panel is placed. If the bleachers are full span, make sure there is some way to access the contol panel if there is a problem. Few people can fit under a retracted set of bleachers...Also, ask your customer if they need data/power/P.A./scoreboard connections for a scorer's table. Those are often overlooked in my experience.

 

[kwired]

I definitely appreciate all the input, trust me the digging has been done, I'm currently reaching out to the manufacturer for additional info. (ie forgot to ship a CP)

No control panel of any sort was supplied. There's 5 motors operating in sync to open and close telescoping bleachers. Overall length of the bleachers is about 80'.
Individual switches are mounted to each motor as a local disconnect.

It's a single point for connection and the motors are operated by a single, hand operated forward and reverse controller, the controller itself doesn't specify if it's contains thermal protection or not, I'm guessing no. Guess we'll see when the manufacturer responds.

Thanks again

You could have a master controller but each motor still needs individual overload protection. If they have to work in synch then there should likely be interlocking means so if one trips, fails, gets out of synch in any way, it stops the others. I'm guessing it is more likely there is five different sections independent of one another and they just happen to operate at same time.

I can see using a single reversing controller for three phase motors, how are they reversing 115 volt single phase motors? Unless they are wound so that you energize one lead for forward and another for reverse, then it would be simple, but still not convinced you can provide proper overcurrent protection for five of the motors that are mentioned unless they have internal overload protection.

 

[RogerD]

Is it still illegal to strangle someone .... lol.

The factory installer told the EC on site that the motors (as noted on nameplate) were not thermally protected. Finally got through to the engineering dept. for the manufacturer and he informed me the the switch mounted on the motor was for the THERMAL PROTECTION! Needless to say, I was ready to scream!

Just have to get the EC now to install a service disconnect and it's all good. Looks like the inspector will sign off now.

Once again thanks everyone.

 

[steve66]

Is it still illegal to strangle someone .... lol.

The factory installer told the EC on site that the motors (as noted on nameplate) were not thermally protected. Finally got through to the engineering dept. for the manufacturer and he informed me the the switch mounted on the motor was for the THERMAL PROTECTION! Needless to say, I was ready to scream!

Just have to get the EC now to install a service disconnect and it's all good. Looks like the inspector will sign off now.

Once again thanks everyone.

Thanks for letting us know how it turned out.

Steve