AEGIS® Bearing Protection - Why Shaft Grounding?

Measuring Shaft Voltages
Shaft Voltage Test Report: Measuring the shaft voltage on VFD driven motors provides the user with valuable information to determine if there is a potential risk of bearing damage from electrical bearing discharges. Surveying and documenting shaft voltage readings and waveforms will assist in determining the appropriate mitigation or solution.
Note: The best time for shaft voltage measurements are during initial start-up
in new or repaired motors operated by the VFD. Shaft voltage measurements
should be incorporated into preventive and predictive maintenance programs
and may be combined with vibration analysis, thermography or other services.

AEGIS-OSC-9100MB-W2
Recommended Testing Equipment: AEGIS® Shaft Voltage Tester™ 100 MHz Digital Oscilloscope with a 10:1 Shaft Voltage Probe™ kit. We recommend a minimum 100MHz bandwidth to accurately measure the high frequency transitions associated with bearing discharge and VFD waveforms.
Recommended Product: PN: AEGIS-OSC-9100MB-W2
- Two 1X/10X probes, one with Shaft Voltage Probe™ SVP Tip attached
- 1000V CAT III multimeter test leads
- AEGIS® One-Touch™ instant image capture feature
- USB flash drive for waveform recording
- 5 hour+ rechargeable/replaceable Li battery
- Carrying case
AEGIS® SVP
Shaft Voltage Probe™
The AEGIS® SVP Shaft Voltage Probe tip
attaches to an oscilloscope voltage
probe to easily and accurately measure
the voltage on a rotating shaft. The high
density of conductive microfibers
ensures continuous contact with the
rotating shaft. The SVP-KIT-9100MB includes replacement tips, extender rods, a magnetic base/probe holder and AEGIS® Ring simulator.

Caution: Use appropriate safety procedures near rotating equipment.
