Vertical hollow shaft motors can fail due to electrical bearing damage. You can prevent this by following shaft grounding best practices.
75HP 1800 460/3/60 TEFC 365TP Vertical HOLLOSHAFT ''P'' Base TUCI W/ INTERNAL SHAFT GROUNDING RING 1.15SF - MEP Inc.
During Commissioning, Testing Shaft Voltage on VFD-driven Motors is a MUST!
FHN Series Parallel Shaft Helical Gear Reducer with Power Lock-Box Size 97-80:1 Ratio-213/5TC - WorldWide Electric Corporation
ODP Grounding Ring, GR-320/400TS - WorldWide Electric Corporation
Processes, Free Full-Text
Hello! I was wondering what purpose the hollow shaft, going through the laminated core serves in this AC generator rotor. : r/ElectricalEngineering
Motor Shaft Grounding
AEGIS Shaft Grounding Rings, AEGIS Canada
Vertical Hollow Shaft
BALDOR JL1303A 1/2HP 3450 56J ODP
Shaft Grounding, Shaft Grounding, Variable Speed, AC Motors - NEMA, Electric Motors
Product Overview Brochure - Shaft Grounding Systems