Motor Terminator OCP

[spectrum]

I'm installing a 100HP 480VAC 3PH motor along with its motor terminator. There is a VFD controlling the motor. Do I need to follow the tap rules when installing the terminator at the motor? We're running 1/0 wire to the motor but the terminator only has #10 wire. Can't I just connect the terminator to the motor leads and call it good?

 

[petersonra]

Re: Motor Terminator OCP

Originally posted by spectrum:
I'm installing a 100HP 480VAC 3PH motor along with its motor terminator. There is a VFD controlling the motor. Do I need to follow the tap rules when installing the terminator at the motor? We're running 1/0 wire to the motor but the terminator only has #10 wire. Can't I just connect the terminator to the motor leads and call it good?

I have often wondered about this myself. As best I can tell, the intent of the manufacturer is that the terminator be mounted right on the motor terminals without any fusing. Maybe the terminator manufacturer can give you some insight.

I did some looking years ago and came to the conclusion that the NEC does not specifically cover this device, so that gives you a fair amount of latittude to install it in accordance with the manufacturer's instructions.

 

[ron]

Re: Motor Terminator OCP

Tap rules involve overcurrent protection for the tap. Does the "terminator" have overcurrent protection internal? Does it have installation instructions?

 

[ron]

Re: Motor Terminator OCP

This is a portion of the instructions froma terminator (load impedance matching device) that I have seen before.

If you cannot connect the terminator directly to the motor
mounted junction box, an auxiliary junction box can be
used. However, the terminator-to-motor connection length
should be no more than 6 meters (20 feet).

From http://www.ab.com/manuals/dr/1204/1204-5_0.pdf
Also addditonal info about the product
http://www.abjournal.com/sept2001/departments/tech_tips/riding_out.html