Motor Disconnects

[dvcraven0522!]

I am working on a gran elevator project. Class 2 Division 1 environment.

n essence we are bring all motor controls and starters up to code. We are planning to provide a new MCC in "Dog House" on the roof of Bin floor and feed motors below with local start/stop. All starters and disconnect will be located in the MCC no local disconnects.

If I understand the code no local disconnects are required if supervised and disc/starter is able to be lockable in the open position. Is that correct?

Thanks
Dan Craven

 

[augie47]

If you meed the requirements of 430.102(B) exception

 

[charlie b]

I believe that is correct. However, there might be an advantage for future maintenance personnel if each motor does have a local disconnect. Otherwise, they would have to trudge up and down to the MCC, perhaps even several times for a single job, in order to lock out the motor. Just worth a quick thought.

 

[rbalex]

There are several Exceptions permitting LOTO throughout Sections 430.102(A)&(B). They have two key principals:

• A disconnect must actually interrupt or isolate the motor’s current [Section 430.101]; i.e., a disconnect is not a pushbutton or similar control device in the motor’s control circuit. Locking out a control device does’t cut it. Section 430.109 lists recognized disconnecting means.
• A local disconnect cannot introduce an increased hazard. In Classified locations this is because someone may attempt to stop a running motor by opening the local disconnect rather than with the controller. Section 430.102(B)(2)(1) IN No.1 lists a few other non-exclusive examples.

 

[TwoBlocked]

I believe that is correct. However, there might be an advantage for future maintenance personnel if each motor does have a local disconnect. Otherwise, they would have to trudge up and down to the MCC, perhaps even several times for a single job, in order to lock out the motor. Just worth a quick thought.

Yep, and sometimes they may NOT trudge up and down to the MCC. Make safe activities easy for the employees to do.

 

[Jraef]

... Otherwise, they would have to trudge up and down to the MCC, perhaps even several times for a single job, in order to lock out the motor.

Cursing the SOB that designed this all the way on each trip!