close enough?

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petersonra

Senior Member
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Northern illinois
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engineer
Suppose one had a motor rated at 152 kW, 460V, 3 phase and 225 FLA.

this is roughly 204 HP.

Is a VFD rated 200HP and 248A "close enough" to be code legal?
 

Besoeker

Senior Member
Location
UK
Suppose one had a motor rated at 152 kW, 460V, 3 phase and 225 FLA.

this is roughly 204 HP.

Is a VFD rated 200HP and 248A "close enough" to be code legal?
I can't comment on code requirements but, given that the continuous rating of the VFD is about 10% above that of the motor, I'd consider it a practical proposition.
One caveat. A full load current of 225A infers a quite efficient motor with a good power factor.
A combination of say 0.885pf and 96% efficiency would be needed.
Not saying that's impossible.
 
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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I can't comment on code requirements but, given that the continuous rating of the VFD is about 10% above that of the motor, I'd consider it a practical proposition.
One caveat. A full load current of 225A infers a quite efficient motor with a good power factor.
A combination of say 0.885pf and 96% efficiency would be needed.
Not saying that's impossible.

That is what the motor spec sheet says. i doubt it will actually run at full load anyway.
 
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