A plant load profile is more informative than an industry label. Describe normal operation, large load changes and any nonlinear equipment so the proposed design can be assessed against the actual duty.
Translate the application into a specification.
Include rated capacity, voltage ratio, frequency, load profile and installation conditions. State the applicable project standard and any site-specific limits. Confirm the final specification with the engineer responsible for the project.
Compare the same duty and evidence.
Request the proposed model, guaranteed no-load and load losses, the reference conditions and reports covering that model. A broad product range does not establish that every rating or combination is available.
Keep unknowns visible.
Resolve missing specifications before comparing quotations. Confirm delivery, testing, installation and maintenance responsibilities with each manufacturer.