Maintenance; Pump; Mechanical Shaft Seals; Motor - Grundfos NB Series Installation And Operating Instructions Manual

12. Maintenance

Warning
Before starting work on the product, switch
off the power supply. Make sure that the
power supply cannot be accidentally
switched on.

12.1 Pump

The pump is maintenance-free.

12.2 Mechanical shaft seals

Mechanical shaft seals are maintenance-free,
working almost without any leakages. If any
considerable and increasing seepage occurs, check
the mechanical shaft seal immediately. If the sliding
surfaces are damaged, replace the entire shaft seal.
Treat mechanical shaft seals with the greatest care.

12.3 Motor

Check the motor at regular intervals. It is important
to keep the motor clean in order to ensure adequate
ventilation. If the pump is installed in a dusty
environment, clean and check it regularly.

12.4 Lubrication

Motor bearings
Motors up to and including frame size 132 have
maintenance-free, greased-for-life bearings.
Motors larger than frame size 132 must be greased
according to the indications on the motor nameplate.
Grease spills from the motor may occur.
Grease specifications: See section
grease.
12.4.1 Bearing grease
Use lithium-based grease according to the following
specifications:
• NLGI class 2 or 3
• viscosity of basic oil: 70 to 150 cSt at +40 °C
• temperature range: -30 °C - +140 °C during
continuous operation.
13. Periods of inactivity and frost
Pumps which are not being used during periods of
frost must be drained to avoid damage.
Drain the pump by removing the drain plug. See fig.
24.
Do not tighten the priming plug or replace the drain
plug until the pump is to be used again.
If the pump is to be drained prior to a long period of
inactivity, inject a few drops of silicone oil on the
shaft at the bearing bracket. This prevents the shaft
seal faces from seizing up.

14. Service

If you request Grundfos to service such a pump,
contact Grundfos with details about the pumped
12.4.1 Bearing
liquid, etc. before you return the pump for service.
Otherwise Grundfos can refuse to accept the pump
for service.
Possible costs of returning the pump are paid by the
customer.

14.1 Service kits

Service kits for NB, NBG, see Grundfos Product
Center in www grundfos.com or Service Kit
Catalogue.

15. Technical data

15.1 Electrical data

See the motor nameplate.
protection
Warning
Take care to ensure that the escaping
liquid does not cause personal injury or
damage to the motor or other components.
In hot-liquid installations, pay special
attention to the risk of personal injury
caused by scalding hot liquid.
In cold-liquid installations, pay special
attention to the risk of personal injury
caused by the cold liquid.
Warning
If a pump has been used for a liquid which
is injurious to health or toxic, the pump will
be classified as contaminated.
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