Question: What is the correct type of high temperature grease for the Grundfos built motors?

Answer: The MLE motors use Lithium based electric motor bearing grease, which is not compatible with polyurea based electric motor greases that are standard in other manufacturer’s motors. Grundfos uses Mobile Unirex N3 at the MLE factory. This information is printed on a tag on the motor housing. A lithium-based grease compatible with this must be used. The Grundfos order info for the Lithium-based grease Cartridge is P/N. 91079414. The MLE motors are in the CR, CRE, VLSE and VLSE E-Solutions series.

For more information, go to to https://www.mobil.com/en/industrial/lubricants/products/unirex-n-3 

Installers Tip – When commissioning, bring a label maker and leave the  re-order numbers for this and the replacement seal cartridge kit labeled on the pump. It is just is good professional courtesy for the building owner’s staff for future concerns.

Another useful tip is to use the grease reminder message that automatically shows up on the pump head screen and have the controls contractor add it as a data point to the BMS.  It takes the all the guess-work out from when to service them every time.

This subject often gets glossed over but if not paid attention to will cause expensive damage your investment in the pumps.

The factory recommended preventative maintenance is every six months for extreme use, once a year for severe use and every three years for standard use applications.  Grundfos E-Solutions MLE models 10 HP and under are permanently sealed with no lubrication required.

For additional information, refer to the installation and operations manual that is supplied with the pump.