nec 430.113

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alecnoble

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Hello all
Article 430.113 refers to equipment with energy from more than one source, and requires disconnecting means adjacent to the equipment. Does this refer to just the motor, or the complete installation. We install electrically operated gates at drawbridges. The doors to the gates have door switches that disconnect the control power to the starter, and the gate has a disconnect switch for the motor. Do we have to have an in sight disconnect for all other control power sources such as indicating light limit switches, etc.? We never have but a reviewer on one of our designs believes this to be an NEC requirement. Thoughts?
 
Re: nec 430.113

I'm not quite following you. Usually the power would run through a disconnect to a controler, with the disconnect within sight. Control power would usually come from this controller, so that disconnect would shut off all motor and control power. Then there would be another disconnect at the motor that just shuts off the motor power.

Are you saying the control power comes from somewhere else? Or that you don't have a disconnect at the controller?
 
Re: nec 430.113

Sorry - I didn't explain myself well. We have an MCC in the control house. The bucket can of course be shut off which also kills the control power for the motor starter. In addition, we have door switches that will also interrupt the control power - thats our safety so that if the door is open the starter cannot be electrically energized. In the gate housing we also have a disconnect switch for the motor in case of failure of a door switch or the contactor being forced. That completes the motor control and power circuits. In addition, we have limit switches for indication and interlocking control relays that have separate control power, but no disconnect for these circuits at the gate. My question is whether the NEC requires a local disconnect for these other control circuits.
 
Re: nec 430.113

The reviewer's comment is the result of several unintended consequences caused by monkeying with Part IX over the years. For example, 430.113 Exception No 1 could now be interpreted as an ?alternate? exception to 430.102 (B) Exception.

In any case, Section 430.113 should be interpreted in context of 430.101 which limits the application of Part IX to disconnecting means for motors and motor controllers.

Control devices are NOT necessarily controllers themselves. See the definition of ?controller? in Section 430.2 and compare it with the definition in Art 100.

The original purpose for 430.113 was motor space heaters with a "foreign source." They remain energized even if the motor and/or controller is disconnected. In addition, depending on how it is controlled the circuit may be routed through an auxiliary switch in the motor controller, so signage may be necessary in both locations.
 
Re: nec 430.113

Thanks Bob - that was what I felt but wasn't sure. Reading the articles was getting confusing. As a point though, I realized how easy it would be to put isolating terminal blocks in so I might do that in the future.
 
Re: nec 430.113

Hello again Bob
We just spent some time re-reviewing the definitions of "controller" in 430 and 100. Thanks - that explains a lot of the confusion...
 
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