system start-up

[abuse]

After a 4 hr. run test of an uncoupled motor that is rated 600 HP, 480
VAC, 60 hz. what should the amp. reading not be more than?

What should it be after 6 hr. run test?

And after 8 hr?

 

[Bob Peterson]

something under FLC I would guess.

I would guess the readings would be about the same for all three cases.

 

[Don Kelly]

After a 4 hr. run test of an uncoupled motor that is rated 600 HP, 480
VAC, 60 hz. what should the amp. reading not be more than?

What should it be after 6 hr. run test?

And after 8 hr?

about same for all times. However, you have omitted the kind of motor and
its class so any value for no -load current is a guess. If it is an
induction motor- no load current will be in the neighborhood of half the
rated current.
If you are getting something near full load current -run- don't walk- to
get the nearest technician.

 

[daestrom]

After a 4 hr. run test of an uncoupled motor that is rated 600 HP, 480
VAC, 60 hz. what should the amp. reading not be more than?

What should it be after 6 hr. run test?

And after 8 hr?

You've omitted some info, but 'uncoupled' means completely unloaded. This
is not a valid 'run test' for any motor. You might as well just shut it
down after 20 minutes. It isn't going to be up to rated temperatures.
Current will be the 'unloaded' value (<10% of rating). After 4 hours, it
won't change at all.

Why in the world would you run it unloaded for such a long time?? It proves
nothing.

daestrom

 

[abuse]

You've omitted some info, but 'uncoupled' means completely unloaded. This
is not a valid 'run test' for any motor. You might as well just shut it
down after 20 minutes. It isn't going to be up to rated temperatures.
Current will be the 'unloaded' value (<10% of rating). After 4 hours, it
won't change at all.

Why in the world would you run it unloaded for such a long time?? It proves
nothing.

daestrom

im an electrician and these were questions (this and the hypot question)
on an ISO certification test. i didnt design the test im just seeing
what this group thought. i agree that running a motor test for so long
serves no purpose.