best practices for protecting large motors and generators ... · best practices for protecting...
TRANSCRIPT
BEST PRACTICES FOR Protecting Large Motors and Generators
from Damaging Bearing Currentswith AEGIS® iPRO Rings
iPROBEARING PROTECTION RING
Problem: VFD-Induced Shaft Voltages and Circulating CurrentsWhen not properly mitigated, VFD-induced shaft voltages and circulating currents in large motors and generators, including
Low-voltage motors: 500 HP or greater Medium-voltage motors DC motors: 300 HP or greater
cause electrical damage in bearings, resulting in motor failure and downtime.
Solution: Install an AEGIS® Ringon the motor shaft’s drive end...Installing an AEGIS® iPRO Ring on the motor‘s drive end will provide a path of least resistance, channeling damaging VFD-induced currents away from bearings and safely to ground. Apply AEGIS® Colloidal Silver Coating to the shaft (where the ring’s microfibers will make contact) to improve conductivity and prevent oxidation.
Electrical discharge machining — pitting and frosting
Fluting damage to bearing race — a washboard pattern from electrical discharges
© 2014 Electro Static Technology
...and insulate the shaft’s non-drive end
AEGIS® iPRO: Designed and Built for Maximum Bearing Protection and Long Life
The AEGIS® iPRO is a larger, beefier version of the AEGIS®
Bearing Protection Ring with the greater current-carrying capacity required for larger motors and generators. Through revolutionary AEGIS® Nanogap Technology,
it ensures effective electrical contact whether in physical contact with the motor shaft or not. Maintenance-free, it provides superior bearing protection for the normal service life of the motor’s bearings.
6 rows of conductive microfibers provide greater current-carrying capacity for larger motors
Specially engineered microfibers flex without breaking, protect bearings for the life of motor
Patented FiberLock™ Channel secures fibers and protects them from contamination
ShaftShaft
AEGIS® Ring
FiberLock™ Channel
SlimLineAEGIS® iPRO Rings
The AEGIS® iPRO has six rows of specially engineered conductive microfibers that encircle the motor shaft and ensure continuous electrical contact whether they are physically touching the shaft or merely in nanogap proximity to it. Containing hundreds of thousands to millions of microfibers, these rows provide the high current-carrying capacity required for large motors.
Through their patented design, AEGIS’s proprietary conductive microfibers are designed to flex without breaking. They exhibit only minimal wear and last for the bearing life of the motor. In testing, they were proven to withstand 2 million direction reversals and over 200,000 hours of continuous operation (to 1800 RPM) with no fiber fatigue or breakage.
AEGIS’s patented, protective FiberLock™ channel locks the ring’s conductive microfibers securely in place around the motor shaft, allowing them to flex without breaking. The channel also helps protect fibers from excessive dirt, oil, grease, and other contaminants.
To interrupt the path of high-frequency circulating currents (common in large motors), install insulated bearings or sleeves on the non-drive end of the motor shaft.
For vertical pump motors, insulate the bearing carrier.
EMQ-Insulated Sleeves
HYBRID CERAMIC BEARINGS
COATED BEARINGS
INSULATED CARRIERS
INSULATED SLEEVES
Insulated Carrier Service
Non conductive rolling element made of silicone nitride
Insulates the bearing against the passage of currents
Provides extended grease life
Lower operating temperatures
Available with shields and seals
Available from stock size range from 6203 thru 6332
These bearings have electrical insulating coatings to protect against damage caused by the passage of electrical currents.
Available from stock size range from 6212 thru 6332
SKF INSOCOAT INSUTECT
FAG INSUTECT
NKE Electrically Insulated Roller Bearings
Manufactured in SAE 1026 Steel
Coated with a Thermoplastic Polymer Alloy
Dielectric strength of 1,000 volts per mil.
Supplied with insulating washers made from G10 material.
Available from stock size range from 6202 thru 6240
• Documented Tolerances • Ground Finish • Carriers are inspected for radial & axial run out • 50 Rockwell C Hardness • Electrical Integrity Test Standard 1 GΩ at 1033V • This Technology Can Be Applied to Any OEM Carrier • Fast Turnaround Time
EMQ-Insulated Sleeves
HYBRID CERAMIC BEARINGS
COATED BEARINGS
INSULATED CARRIERS
INSULATED SLEEVES
Insulated Carrier Service
Non conductive rolling element made of silicone nitride
Insulates the bearing against the passage of currents
Provides extended grease life
Lower operating temperatures
Available with shields and seals
Available from stock size range from 6203 thru 6332
These bearings have electrical insulating coatings to protect against damage caused by the passage of electrical currents.
Available from stock size range from 6212 thru 6332
SKF INSOCOAT INSUTECT
FAG INSUTECT
NKE Electrically Insulated Roller Bearings
Manufactured in SAE 1026 Steel
Coated with a Thermoplastic Polymer Alloy
Dielectric strength of 1,000 volts per mil.
Supplied with insulating washers made from G10 material.
Available from stock size range from 6202 thru 6240
• Documented Tolerances • Ground Finish • Carriers are inspected for radial & axial run out • 50 Rockwell C Hardness • Electrical Integrity Test Standard 1 GΩ at 1033V • This Technology Can Be Applied to Any OEM Carrier • Fast Turnaround Time
Hybrid Ceramic Bearings
Insulated Carriers
Insulated Sleeves
Coated Bearings
BEARING PROTECTION RING
iPRO Rings are available in a range of styles…
and Mounting Options
You Provide Motor Dimensions, We’ll Provide a Quote
AEGIS® iPRO Solid Ring AEGIS® iPRO Split Rings
All AEGIS® iPRO Rings are
custom-manufactured to the
measurements you provide.
So, in order to provide an
accurate quote, we must have
precise motor measurements.
iPRO Rings cannot be
returned due to errors
in these measurements.
If you have any questions,
please contact
AEGIS® Customer Service:
NEMA ‘U’shaftdiameter
Stepdiameter
Distance from mounting faceto end of shaft step
Mounting faceouter diameter
Mounting faceinner diameter
Distance from mountingface to end of shaft
Distance from mountingface to shaft key
Distance from mounting faceto attached equipment
Measure dimensions to: Inches: 3 decimal places / Metric: 2 decimal places
Bearing Cap MountingCustom Brackets Mounting Plate
207-998-5140sales @ est-aegis.comwww.est-aegis.com
Form 701-1/10-2014
1-866-738-1857