Motors with kW ratings only

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collins

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How do you determine the FLC of a motor that is only rated with a kW, as in Table 430.250? Does a 5kW convert to 6.7HP which rounds upto 7.5HP in the table?
 
430.7(A) tells us the motor "shall" be marked with a nameplate which includes voltage, FLC and HP. Why does this one not identify?

Your math looks good.......746 watts in a HP.
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I would argue they cannot be used because they are not NEC compliant.

However, if they are part of an assembly, such as a machine, they would not be part of the premises wiring, and thus arguably not covered by the NEC.
 
collins said:
motors are coming from Europe mounted on pumps
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I've seen many European and Asian motors on systems purchased for use in the USA, some with and some without 60Hz ratings. I've never seen one without a name tag that had power, voltage, frequency, and FLA. Is it possible that the OEM removed the tag? Who made the motor?

Many pumps will have increased drive requirements other than the 6:5 inherent speed increase. Be wary, but not necessarily beware.

Side note ... in much of Europe, motors above 5.5kW (used to be, don't know present rules) were required to be started via some reduced current system. It used to "always" be wye-delta. The light frames some use don't always take kindly to across-the-line starting.
 
There is a nameplate, but no HP rating on it, only kW.
Although the motor itself may not be covered by NEC, I would like to design the control for it to the NEC. I thought it was unusual that they would not list have both HP & kW in the Tables.
 
KW X 1.341 = HP. You will never get an exact number like 7.5, but you will be close. So if you come up with 9.6 HP, you have a 10 hp motor. Always round up. With the KW converted to HP you can use HP to calculate wire size, protection ect....
 
collins said:
How do you determine the FLC of a motor that is only rated with a kW, as in Table 430.250? Does a 5kW convert to 6.7HP which rounds upto 7.5HP in the table?
Click to expand...

430.6 Ampacity and Motor Rating Determination.
......
​
(A) General Motor Applications.​
​
​
For general motor applications,
current ratings shall be determined based on
(A)(1) and (A)(2).​

(1) Table Values.​
​
​
Other than for motors built for low
speeds (less than 1200 RPM) or high torques, and for multispeed
motors, the values given in Table 430.247, Table
430.248, Table 430.249, and Table 430.250 shall be used to
determine the ampacity of conductors or ampere ratings of
switches, branch-circuit short-circuit and ground-fault protection,
instead of the actual current rating marked on the
motor nameplate. Where a motor is marked in amperes, but
not horsepower, the horsepower rating shall be assumed to
be that corresponding to the value given in Table 430.247,
Table 430.248, Table 430.249, and Table 430.250, interpolated
if necessary.
.......​

(2) Nameplate Values. ​
​
Separate motor overload protection
shall be based on the motor nameplate current rating.​


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dbuckley said:
HP is becoming a dated unit in many parts of the world.

My car is rated in KW, fore heavens sake...
Click to expand...

So is my outboard engine on it's name plate info.

Roger
 
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