Motors on SO cord

[Just_Sum_Guy]

I'm sure someone can help me out here...I am trying to determine if the Code will allow small (less than 2HP) 3 phase ac motors to be permanantly installed using flexible type cord (ie SO) and use a "listed for use" (as in 430.109(F)) attachment plug and cord connector?
I guess my question really goes back to Flexible Cords, Uses Permitted 400.7(6) and 400.7(10). These motors are driving pumps in an industrical facility. 400.7(6) cites "frequent interchange", but what is considered "frequent"? Also, 400.7(10) cites "where specifically permitted elsewhere in this Code". Ok, since 430.109(F) discusses Cord and Plug connected motors, does that allow the motors to be installed using cord and plug as long as the conditions of 430.109(F) are met? Thanks for the help.

 

[kwired]

I'm sure someone can help me out here...I am trying to determine if the Code will allow small (less than 2HP) 3 phase ac motors to be permanantly installed using flexible type cord (ie SO) and use a "listed for use" (as in 430.109(F)) attachment plug and cord connector?
I guess my question really goes back to Flexible Cords, Uses Permitted 400.7(6) and 400.7(10). These motors are driving pumps in an industrical facility. 400.7(6) cites "frequent interchange", but what is considered "frequent"? Also, 400.7(10) cites "where specifically permitted elsewhere in this Code". Ok, since 430.109(F) discusses Cord and Plug connected motors, does that allow the motors to be installed using cord and plug as long as the conditions of 430.109(F) are met? Thanks for the help.

Do you need to "unplug" the equipment on any kind of regular basis for routine maintenance, cleaning, setup, breakdown, replacement, etc.? Any of those situations is considered frequent interchange to most people.

 

[petersonra]

For small motors like this where you need to get them out now and then, I don't see a problem. For reasons that I have never understood people seem to obsess over not using cord to hook things up. It seems like a perfectly rational and safe way to do things a lot of time and IMO the code ought to allow it more often than the limited places it does.

We have several customers that do it on a routine basis because in their applications they need to move the motors now and then as part of normal operation of the equipment (for cleaning mostly).

I don't know what is frequent. Normally a motor would not need to be disconnected more than once every few years so more often than that seems pretty frequent to me.