Motor Control Disconnect for all Sources

[Natfuelbilll]

430.75 Disconnection.
(A) General. Motor control circuits shall be arranged so that they will be disconnected from all sources of supply when the disconnecting means is in the open position. The disconnecting means shall be permitted to consist of two or more separate devices, one of which disconnects the motor and the controller from the source(s) of power supply for the motor, and the other(s), the motor control circuit(s) from its power supply. Where separate devices are used, they shall be located immediately adjacent to each other.

How often do you also install control circuit supply?

Ever been flagged by inspector?

Does above include 24V control voltage?

 

[sameguy]

How often- when ever the print or engineer calls for it.
Most often the inspector is from the facility, large industrials not the out side AHJ. Big MCC.
Low voltage- see the rest of 430.75(B) "reduced voltage".
Are you into an application or ?

 

[pfalcon]

430.75 Disconnection.
(A) General. Motor control circuits shall be arranged so that they will be disconnected from all sources of supply when the disconnecting means is in the open position. The disconnecting means shall be permitted to consist of two or more separate devices, one of which disconnects the motor and the controller from the source(s) of power supply for the motor, and the other(s), the motor control circuit(s) from its power supply. Where separate devices are used, they shall be located immediately adjacent to each other.

How often do you also install control circuit supply?

All the time - 430.75(B)

Ever been flagged by inspector?

No, but I get to flag a few vendors. :grin:

Does above include 24V control voltage?

Absolutively. And we prefer that voltage for control circuits.

 

[weressl]

430.75 Disconnection.
(A) General. Motor control circuits shall be arranged so that they will be disconnected from all sources of supply when the disconnecting means is in the open position. The disconnecting means shall be permitted to consist of two or more separate devices, one of which disconnects the motor and the controller from the source(s) of power supply for the motor, and the other(s), the motor control circuit(s) from its power supply. Where separate devices are used, they shall be located immediately adjacent to each other.

How often do you also install control circuit supply?

Ever been flagged by inspector?

Does above include 24V control voltage?

1. How often do you also install control circuit supply?
- Control circuit is either integral or external. (I presume you are calling control circuit that controls the contactor in the MCC bucket.)When it is integral the CPT is fed by the main disconnect, so it automatically disconnects when the main is opened. If it is external, then it goes through an auxiliary contact of the main disconnect. There are often 'foreign' voltage sources in the MCC compartment that land on dry contacts of the contactor for interlock or status indication, I would call that signal circuit supply. Whenever there is a foreign voltage source in the compartment, there will be a warning label on the door.

3. Does above include 24V control voltage?
If the 24VDC is a control it gets the aux contact treatment, although IMO it should not be necessary.