Twc 04.doc

TO WEG CUSTOMERS
New grease for WEG Motors and Generators
“POLYREX® EM”
1- INTRODUCTION:
WEG’s continuous dedication to R & D and a strong belief in the importance of
producing and delivering products and services of superior quality, have been
paramount in WEG’s past and continuing growth. Guided by this principle, Weg is
now replacing the existing Unirex N2 grease on its motors and generators with a
new and superior quality grease, POLYREX EM. This new grease was specially
formulated for electric motor bearings (The “EM” in the name means Electric
Motors). By using POLYREX EM as standard, WEG continues with its strong
belief that technology is the key to the future.
This change applies to all Weg motors and generators in the following frame sizes:- Weg W21Motors: IEC 160 to 355 (Nema 254T to 587T) Weg Maquinas: all motor sizes and generators.
2 – FEATURES AND BENEFITS:
Specially formulated for lubricating electric motors bearings, the new grease
POLYREX® EM extends significantly bearing lubrication intervals. (See attached
tables IEC and NEMA).
2.2 LONG-LIFE HIGH TEMPERATURE PERFORMANCE: According to ESSO/EXXON, in the ASTM D 3336 High-Temperature Grease LifeTest POLYREX® EM achieved a lubrication life of more than 700 hours at 177°C(350°F), more than four times better than a competitive polyurea grease and morethan seven times better than conventional lithium-complex greases. (See fig. 1) TO WEG CUSTOMERS
2.3 EXCELLENT MECHANICAL SHEAR STABILITY: The thickener of POLYREX® EM exhibits excellent durability and stability whensubjected to a mechanical shearing force.
2.4 RESISTS WATER WASHOUT AND CORROSION PROTECTS AGAINSTWEAR: POLYREX® EM contains an additive system specially formulated to resist waterwashout and metal corrosion and protect bearing surfaces from wear underboundary lubrication conditions. The excellent corrosion prevention characteristicsof POLYREX® EM were impressively demonstrated in the EMCOR Corrosion Test,in which POLYREX® EM protected bearing races from rust, even when submergedin a solution containing 10% synthetic sea water.
The new grease is compatible with any lithium or lithium complex based grease.
This means that they can be mixed without any problems, however one cannotexpect the same improved performance with the mixed greases than with usingonly POLYREX® EM. From August 2001 on all WEG motors in frame IEC 160(NEMA 254T) and above will be manufactured with POLYREX® EM .WEGrecommends to use the new grease, due to the advantages described above.
TO WEG CUSTOMERS
IEEE 841 states that motors for chemical applications require a grease withpolyurea base, therefore all WEG off-the-shelf motors are already suitable for thisapplication from now on.
3 – IMPLEMENTATION DATE:
Motors in frames 160 to 355 (Nema 254T to 587T) are being supplied with
POLYREX EM since July of 2001.
All low and high voltage motors and generators will be supplied with POLYREX
EM from August of 2001.
4 – DOCUMENTATION:
In order to have the complete change covered, WEG is taking the following internalactions: Ø Updating general catalogs to the new type of grease recommended by WEGØ Updating the Installation and Maintenance Manual that goes with the motor in Ø Changing motor nameplates replacing “lithium base” by “POLYREX® EM”.
For further information, please contact your closest WEG sales office.

Source: http://www.weg.co.nz/download_file.cfm/Polyrex_EM_Grease.pdf?id=46,f