Hello All, :smile:
We are installing a VFD multiconductor cable similar to a power cord in a ladder type open cable tray.
http://www.amercable.com/doc/catalogs/vfd/37-102VFD.pdf
The cable is from a VFD to two different style motors. The first is a 125 hp motor with a full load current of 212 amps located 750 feet from the VFD and the second is a 250 hp motor with a full load current of 324 amps located 200 feet from the VFD's.
According to the NEC I need to size the cable at 125% for the starting current and continuous duty rating. Based on the NEC calculation, the currents required by the cable are 265 amps and 405 amps.
The motor and VFD will be terminated with Hy-Press connections so I assume we can use the 90C ratings. Based on the manufactures rating sheet, the cable sizes at 90 C would be a 313 MCM and a 262 MCM.
The manufacture lists this cable with 95-110 C ratings also.
My question is can I use any rating higher than 90 C and if so under what circumstances?
We are installing a VFD multiconductor cable similar to a power cord in a ladder type open cable tray.
http://www.amercable.com/doc/catalogs/vfd/37-102VFD.pdf
The cable is from a VFD to two different style motors. The first is a 125 hp motor with a full load current of 212 amps located 750 feet from the VFD and the second is a 250 hp motor with a full load current of 324 amps located 200 feet from the VFD's.
According to the NEC I need to size the cable at 125% for the starting current and continuous duty rating. Based on the NEC calculation, the currents required by the cable are 265 amps and 405 amps.
The motor and VFD will be terminated with Hy-Press connections so I assume we can use the 90C ratings. Based on the manufactures rating sheet, the cable sizes at 90 C would be a 313 MCM and a 262 MCM.
The manufacture lists this cable with 95-110 C ratings also.
My question is can I use any rating higher than 90 C and if so under what circumstances?
