MEGAOHM™
The insulated bearing that protects electric motors against electrical erosion
Prevent premature failures
and safeguard electric motors fitted
with variable speed drives
Electric motors account for 46% of global electricity consumption.
To address global energy efficiency challenges, European regulations require motors to be upgraded to higher energy efficiency classes (IE3, IE4 and now IE5), which is leading to the widespread use of variable frequency drives (VFDs) and causing unexpected breakdowns.
ELECTRICAL-EROSION: A MAJOR CAUSE
OF ELECTRIC MOTOR FAILURE
The installation of variable-frequency drives
The majority of electric motors are now fitted with variable frequency drives (VFDs). VFDs optimise motor operation and energy consumption, but they also alter the internal electrical environment of the motors.
In some cases, they generate high-frequency eddy currents that pass through the bearings. This phenomenon, known as electrical erosion, contributes to the premature failure of the component and, subsequently, to motor failure.
Furthermore, these eddy currents impair lubrication – the second leading cause of failure – thereby significantly reducing the bearing’s service life.
ELECTRICAL-EROSION: A MAJOR CAUSE
OF ELECTRIC MOTOR FAILURE
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The installation of variable-frequency drives
The majority of electric motors are now fitted with variable frequency drives (VFDs). VFDs optimise motor operation and energy consumption, but they also alter the internal electrical environment of the motors.
In some cases, they generate high-frequency eddy currents that pass through the bearings. This phenomenon, known as electrical erosion, contributes to the premature failure of the component and, subsequently, to motor failure.
Furthermore, these eddy currents impair lubrication – the second leading cause of failure – thereby significantly reducing the bearing’s service life.
What is the phenomenon
of electrical erosion?
Electric current flows through the bearing.
Current leakage causes weakness in the material.
Small metal particles are breaking away from the bearing components.
These particles move around and cause cracks and pitting.
Electro-erosion is a phenomenon caused by stray electrical currents passing through the bearing. These repeated electrical discharges can lead to: pitting, cracking, deterioration of the lubricant, etc.
Without suitable protection, electrical erosion significantly reduces the bearing’s service life and can lead to premature motor failure and increased maintenance costs.
QU’EST-CE QUE LE PHÉNOMÈNE
D’ÉLECTRO-ÉROSION ?
What is the phenomenon
of electrical erosion?
1 - Electric current flows through the bearing.
2- Current leakage causes weakness in the material.
3- Small metal particles are breaking away from the bearing components.
4- These particles move around and cause cracks and pitting.
Electro-erosion is a phenomenon caused by stray electrical currents passing through the bearing. These repeated electrical discharges can lead to: pitting, cracking, deterioration of the lubricant, etc.
Without suitable protection, electrical erosion significantly reduces the bearing’s service life and can lead to premature motor failure and increased maintenance costs.
QU’EST-CE QUE LE PHÉNOMÈNE
D’ÉLECTRO-ÉROSION ?
How can bearings be protected
against electrical erosion?
There are several ways to minimise the effects of stray currents.
Their effectiveness varies depending on voltage levels,
rotational speeds and the constraints of the application.
CONDUCTIVE
GREASES
Protection type
Dissipates current
Electrical efficiency
Low, unstable
Applications
Small motors, domestic
appliances
INSULATED BEARINGS
RESIN
Protection type
Insulating on the outer ring
Electrical efficiency
Good up to 1000 V but does not operate above 120°C.
Applications
Low-voltage motors,
cost-effective insulation
INSULATED BEARINGS
CERAMIC (MEGAOHM™)
Protection type
Insulating on the outer ring
Electrical efficiency
Very high up to 3000 V
Applications
AC motors, wind turbines,
generators
HYBRID
BEARINGS
Protection type
Insulating
Electrical efficiency
Complete and permanent
Applications
Electric vehicles, high-speed applications,aerospace
Protection type: dissipates current
Electrical efficiency: low, unstable
Applications: small motors, domestic appliances
Protection type : insulating on the outer ring
Electrical efficiency: good up to 1000 V but does not operate above 120°C.
Applications: low-voltage motors, cost-effective insulation
Protection type: insulating on the outer ring
Electrical efficiency: very high up to 3000 V
Applications: AC motors, wind turbines, generators
Protection type: insulating
Electrical efficiency: complete and permanent
Applications: electric vehicles, high-speed applications,aerospace
Among these solutions, the ceramic-coated insulated
bearing is the most widely used and offers the best
balance between performance and cost for protecting
industrial motors against electrical erosion.
MEGAOHM™: NTN’S BRANDED SOLUTION FOR ENSURING
THE LONG-TERM RELIABILITY OF ELECTRIC MOTORS
The MEGAOHM™ insulated bearing
has been specially developed to protect
electric motors against damage
caused by stray currents.
High-performance electrical insulation:
a thick alumina ceramic coating
on the outer surface of the
outer ring.
Higher electrical resistance:
up to 3,000 VDC compared with
1,000 VDC – 100 µm for standard solutions.
2 ranges available:
steel cage and brass cage.
(depending on motor size)
Interchangeability:
dimensions compatible
with a standard bearing.
MEGAOHM™: NTN’S BRANDED SOLUTION FOR ENSURING
THE LONG-TERM RELIABILITY OF ELECTRIC MOTORS
The MEGAOHM™ insulated bearing
has been specially developed to protect
electric motors against damage
caused by stray currents.
High-performance electrical insulation:
a thick alumina ceramic coating
on the outer surface of the
outer ring.
Higher electrical resistance:
up to 3,000 VDC compared with
1,000 VDC – 100 µm for standard solutions.
2 ranges available:
steel cage and brass cage.
(depending on motor size)
Interchangeability:
dimensions compatible
with a standard bearing.
Performance suited to the most demanding applications
The MEGAOHM™ bearing is recommended for all applications exposed to the effects of stray currents:
AC/DC MOTOR
SERVOMOTORS
PUMPS
DES PERFORMANCES ADAPTÉES
AUX APPLICATIONS LES PLUS EXIGEANTES
Le roulement MEGAOHM ™ est recommandé pour toutes les applications exposées aux effets des courants parasites : /span>
FANS
COMPRESSORS
Performance suited to the most demanding applications
The MEGAOHM™ bearing is recommended for all applications exposed to the effects of stray currents:
AC/DC MOTOR
SERVOMOTORS
PUMPS
FANS
COMPRESSORS
Why choose the MEGAOHM™
bearing?
MEGAOHM™ meets the needs of winding technicians and maintenance engineers looking for a reliable, high-performance solution that is available quickly.
Maximum protection against stray currents: resistance up to 3000 VDC.
Extended service life of bearings and motors.
Dimensions and tolerances: manufactured in accordance with ISO 492, DIN 620 and JIS 1514 standards.
Immediate availability: product available from stock to respond quickly to maintenance requirements.
Why choose the MEGAOHM™
bearing?
MEGAOHM™ meets the needs of winding technicians and maintenance engineers looking for a reliable, high-performance solution that is available quickly.
Maximum protection against stray currents: resistance up to 3000 VDC.
Extended service life of bearings and motors.
Dimensions and tolerances: manufactured in accordance with ISO 492, DIN 620 and JIS 1514 standards.
Immediate availability: product available from stock to respond quickly to maintenance requirements.
NTN SUPPORTS PROFESSIONALS
IN THE FIELD OF ELECTRIC MOTOR
MAINTENANCE
Beyond the MEGAOHM™ insulated bearing, NTN supports winding specialists and maintenance technicians in their work with a comprehensive range of products dedicated to equipment maintenance and reliability.
This expertise addresses a variety of on-site challenges: polluted environments, high speeds, high temperatures, shocks and vibrations.
- Ball bearings
- Angular contact bearings
- Cylindrical roller bearings
- TOPLINE range
- EMTR / High-performance
sealed bearings
- Mounting tools
- Suitable lubrication
- Training
Are you looking for a bearing to protect
electric motors against electrical erosion?