Maximum Continuous Current in BLDC motor.

Thread Starter

Track99

Joined Jun 30, 2022
38
Hello my friends. The datasheet for the BLDC motor below is saying that the "Maximum Continuous Current" is 21 A (205 s).

1) Does this mean, in normal english, that the motor can draw 21 Amps of current, for a maximum of 205 seconds without damaging the inside of the motor?
2) In a situation where the maximum current is being drawn, does it mean that 21 Amps are going through EACH of the 3 black wires or does it mean that a total of 21 Amps are going through the 3 wires together, into the BLDC motor?

Motor picture is below, friends.
Thank you my friends for the replies.

1668015689718.png
 
Last edited:

nsaspook

Joined Aug 27, 2009
10,706
21 Amps of current, for a maximum of 205 seconds without damaging the inside of the motor? Depends on the degree of cooling.

By convention we usually describe a three phase load by the current in one phase.
 

Thread Starter

Track99

Joined Jun 30, 2022
38
Which datasheet are you reading - can't see that limitation for the KDE 8218XF-120
You are correct Irving. I used rough numbers, for this post, and a rough picture, because I didn't have the motor in front of me on the table.
The real numbers are: Maximum Continuous Current* 142 A (180 s).
It is a KDE10218XF-105
 

Thread Starter

Track99

Joined Jun 30, 2022
38
Although if true BLDC there is only two conductors carrying current at any one time, no 3 phase applied.

Thank you my friend.

From your post I will make 3 guesses:

1) When measuring the current, we will see a total of 21 Amps drawn , together, by 2 of the 3 wires ( by wires, I mean phases).
I am guessing, if we measure the current in all three phases, then we will see a total of 21 Amps drawn together by ONLY, ANY 2 wires at any given point in time.
2) We will never see 21 Amps drawn through ONLY one wire ( by wires, I mean Phase. )
3) We will never see 21 Amps drawn though ALL 3 wires. ( by wires, I mean Phases. )

Are my guesses correct my friend?
Thank you
 

JuliaSmith

Joined Nov 9, 2022
6
Yes all 3 wires will conduct a total of 21 A current and the maximum power the motor that the motor can consume is 21A.So technically the motor will provide it highest speed with 21 A of current supply
 
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