Disconnect for a Motorized piece of equipment
- Thread starter wmeek
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renosteinke
Senior Member
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- NE Arkansas
It's not that bad of a question. As usual, the devil is in the deatils, and 'good design' might differ from 'code minimum.'
What's a 'controller?' If we're talking about industrial controls here, it's quite possible that even with the handle locked in the "off" position there is plenty of 'hot' circuits in that box. Likewise, the machinery might still have power to all manner of accessories, sensors and controls on it, with just power to the main motor disconnected.
For example, the starter to a table saw probably has a 'foreign' circuit passing through, to operate the shop central dust collector when the saw is running.
What's a 'controller?' If we're talking about industrial controls here, it's quite possible that even with the handle locked in the "off" position there is plenty of 'hot' circuits in that box. Likewise, the machinery might still have power to all manner of accessories, sensors and controls on it, with just power to the main motor disconnected.
For example, the starter to a table saw probably has a 'foreign' circuit passing through, to operate the shop central dust collector when the saw is running.
The NEC doesn't imply anything. It states requirements. That said:
Generally, any disconnecting means may serve for all downstream components provided that it meets all the requirements of the downstream component disconnect. Such as "in sight" for motors or controllers.
Disconnecting and locking out a controller in and of itself does not automatically qualify as sufficient for any downstream components. It is always possible that the controller supplies "control" without supplying "power". A motor disconnect for example requires all sources of supply to be disconnected 430.75(A). Although upstream from the motor such a controller's disconnect would not serve for the motor.
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