# Motor disconnect



## 460 Delta (May 9, 2018)

This will sound silly to most of you, but help me understand 430.102B1. Does this state that all motors not in the line of sight of the motor controls (the MCC) have to have a safety disconnect?


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## micromind (Aug 11, 2007)

I have a 2005 codebook so this may have been changed but there's an exception to 430.102(B) that doesn't require the motor disconnect to be in sight if the controller can be locked out.


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## splatz (May 23, 2015)

The way I'm reading it, the motor disconnect can be 

403.102(B)(1) a separate disconnect for the motor, within sight of the motor 

403.102(B)(2) the controller disconnect, if it's within sight of the motor and machinery 

and it is not required if 

403.102(B)(2)(a) the controller disconnect is lockable, and a motor disconnect is impractical or hazardous 

403.102(B)(2)(b) the controller disconnect is lockable, and in an industrial setting blah blah qualified persons blah blah


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## 460 Delta (May 9, 2018)

Thanks micro and splatz, I read it as being able to lock the disconnect at the starter and that will suit the NEC, but I’m rough at best with the code book. 
The situation is I have a roots blower at a plant to connect up and I’m strongly leaning towards split starting the 40hp motor on two NEMA 2 1/2 Furnas starters with a 1~2 second delay. I’m on a older 230 Delta system here and I’m trying to reduce the voltage blip to the office when the driver starts the blower. I pretty much have all the parts to put it together from leftovers from other projects. If I had to have a disconnect at the motor, that would be a no go as I would have to break 6 conductors.


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## CMP (Oct 30, 2019)

Changed in 2014...

*2008 Copy*


> (2) Controller Disconnect. The controller disconnecting
> means required in accordance with 430.102(A) shall be
> permitted to serve as the disconnecting means for the motor
> if it is in sight from the motor location and the driven
> ...


*2014 Copy*


> (2) Controller Disconnect. The controller disconnecting
> means required in accordance with 430.] 02(A) shall be permitted
> to serve as the disconnecting means for the motor if it
> is in sight from the motor location and the driven machinery
> ...


*2017 Copy*


> (2) Controller Disconnect. The controller disconnecting
> means required in accordance with 430.102(A) shall be permitted
> to serve as the disconnecting means for the motor if it is in
> sight from the motor location and the driven machinery location.
> ...


My reading is that now (2017 NEC) the motor located disconnect is required unless you meet one of the exceptions *and* have the controller located lockable disconnect.


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## Breakfasteatre (Sep 8, 2009)

I think the problem is we should be referencing the 1978 codebook in 2021


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## paulengr (Oct 8, 2017)

460 Delta said:


> This will sound silly to most of you, but help me understand 430.102B1. Does this state that all motors not in the line of sight of the motor controls (the MCC) have to have a safety disconnect?


No. The industrial exception applies if they have their own maintenance staff and choose to use it. And you can buy the little Socomec disconnects cheap. It doesn’t need to be a giant several thousand dollar disconnect.


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## 460 Delta (May 9, 2018)

paulengr said:


> No. The industrial exception applies if they have their own maintenance staff and choose to use it. And you can buy the little Socomec disconnects cheap. It doesn’t need to be a giant several thousand dollar disconnect.


Does Socomec have a 6 pole disconnect?


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## paulengr (Oct 8, 2017)

460 Delta said:


> Does Socomec have a 6 pole disconnect?


Yes. It’s a pretty modular system.


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