motor motion control system

[ODonnell]

We are looking at upgrading 3- motor hoist rigs. The contractor is providing a controls package with 3 VFD units and controls. The Package includes individual drive breakers on the front of the rack mounted unit. the power requirement for all the drives in 480V 3-ph., 30A twist lock, main power for the rack mount unit. Simple need. It would seem the breakers themselves would suffice for the disconnect for the motor control systems and that distro is handled internally in the rack mount unit. With the breakers for the individual drives on the unit is there any need for a disconnect for the receptacle cord and plug drop for the unit? thanks!

 

[MTW]

What would you use for a lock out, required when servicing one of the units, while leaving the others operational? Is there provisions for a breaker lockout?
Are the breakers within sight of the hoists?

 

[ODonnell]

hoists are next the racks with the breakers on them. It is cord and plug connected with the 30 amp 480V twist-lock for the whole rack. if interior work is done there is that. individually, good question to put to the vendor, but is is likely any time lockout is needed inside the rack mount unit, all power must be removed, so unplugged.