Insulation Resistance; Servicing The Product; Cleaning Of The Motor; Relubrication Of Motor Bearings - Grundfos CRE Instructions Manual

4. Insulate the three leads from each other by means of insulating
tape or the like.
DANGER
Electric Shock
Death or serious personal injury
‐
Do not bypass the frequency converter by
connecting the power supply leads to the U, V and
W terminals.
‐
This may cause hazardous situations for personnel
as the high voltage potential of the power supply
may be transferred to touchable components in the
terminal box.
Check the direction of rotation when starting up after
switching to emergency operation.
5. A motor starter is required.

7.2 Insulation resistance

20-30 hp
• Do not measure the insulation resistance of an
installation incorporating E-pumps using high voltage
megging equipment, as this may damage the built-in
electronics.
• The motor leads can be disconnected separately and
the insulation resistance of the motor windings can be
tested.
34

8. Servicing the product

8.1 Cleaning of the motor

Keep the motor cooling fins and fan blades clean to ensure
sufficient cooling of the motor and electronics.

8.2 Relubrication of motor bearings

20-30 hp pumps
The motor bearings are of the open type and must be relubricated
regularly. The motor bearings are prelubricated on delivery. The
built-in bearing monitoring function will give a warning indication on
the R100 when the motor bearings are due to be relubricated.
Remove the diaphragm plug in the fan cover to access the grease
nipple in the non-drive end (NDE) of the motor.
When the new grease is injected, the old grease will
escape into the bearing cover inside the motor.
Do not overgrease the bearings. Overgreasing will cause
increased bearing heat and may result in bearing and
motor failure.
Frame size
Drive end (DE)
MLE 160 0.44
MLE 180 0.51
The recommended grease type is a lithium-based lubricating
grease.

8.3 Replacement of motor bearings

20-30 hp motors have built-in bearing monitoring function which will
give a warning indication on the R100 when the motor bearings are
due to be replaced.

8.4 Replacement of varistor (only 20-30 hp)

The varistor protects the pump against voltage transients. If voltage
transients occur, the varistor will be worn over time and need to be
replaced. The more transients, the more quickly the varistor will be
worn. When it is time to replace the varistor, R100 and PC Tool E-
products will indicate this as a warning.
A Grundfos technician is required for replacement of the varistor.
Contact your local Grundfos company for assistance.

8.5 Service parts and service kits

For further information on service parts and service kits, visit
www.grundfos.com, select country, select Grundfos Product Center.
Quantity of grease
[ounces]
Non-drive end (NDE)
0.44
0.51