to find out locked rotor current &load factor
to find out locked rotor current &load factor
(OP)
Hello,
Can anyone help me to find out the rated current/locked rotor current & load factor of a 15KW motor which is connected to 415V ac.Estimated full load current & maximum demand are 26Amps.Load diversification=.06.Thanks in advance.
Can anyone help me to find out the rated current/locked rotor current & load factor of a 15KW motor which is connected to 415V ac.Estimated full load current & maximum demand are 26Amps.Load diversification=.06.Thanks in advance.





RE: to find out locked rotor current &load factor
Load factor, as I use the term, is dependent on the load. If you are referring to Duty Cycle, that should also be on the motor nameplate.
I have no idea what Load Diversification is referring to.
If this is a new(ish) motor, you may be able to get a motor data sheet from the motor supplier.
RE: to find out locked rotor current &load factor
As dpc already said "NEC[NFPA-70] art.430-7 b Locked-Rotor" indicates Code Letters for Usual Motor Application. The manufacturer has to indicate this letter in order to appreciate the locked rotor current [there are 19 letters from A to V and kVA per Horsepower with locked rotor is tabulated].
The load diversification is the ratio between total installed power and maximum required power.
For a single motor connected to a single branch the load diversification is also the load factor.
So, as 26 A is close to the FLA then 26/.06=433 A is very large current for rated current, in your case, I think.
Usually powerfactor=0.8-.9 and efficiency 0.6 to 0.9, then max.Irated may be= 1000*15/415/sqrt(3)/.8/.6=43.5 A
In this case the diversity factor may be 26/43.5=0.6 approx.
For motor manufactured according to IEC 34-12 usually the locked rotor current is expected to be 6.5-7.2 time the rated current [for 15 kW induction squirrel cage motor 1000-3000 rpm].
Regards