Motor Inertia Calculation

[tiftif]

I have a 1750HP IM 13.2kV RPM = 3600 & MVA is 1.424. H=1/2Jw^2/MVA.
I do not know H. I need to get J which is written as J=2H (s).
Anyway to estimate some reasonable value for J?

 

[7anoter4]

It is difficult to appreciate the inertia moment since for modular type it could be 8 kg.m^2[190 lb-ft^2] and for cast iron 40 kg.m^2[950 lb-ft^2].
It would be better if you could ask the manufacturer.