High speed decanter centrifuge is widely used for oilfield drilling mud system, do you know how to test a centrifuge? There are many important parameters for centrifuge, like rotary speed, vibration, bearing temperature increasing, pulley size, treating capacity, etc. 
For a simply inspection tested by clean water, you should at least test vibration, bearing temperature and rotary speed. See the attached photos of inspection centrifuge, you can see where it located and how to test it.
The 2nd step is to use bentonite mud to feed to the centrifuge, to test the performance and treating capacity of the centrifuge. If it is with VFD control panel, you can test it in various frequency during working.