Shaft Seal Run-In; Maintenance; Frost Protection; Service - Grundfos CRT Serie Instrucciones De Instalación Y Funcionamiento

CRT 2 and 4
For these pumps, we advise you to open the bypass valve during
start-up. See fig. 18. The bypass valve connects the suction and
discharge sides of the pump, thus making the filling procedure
easier. Close the bypass valve again when the operation is
stable.
When pumping liquids containing air, we advise you to leave the
bypass valve open if the operating pressure is lower than 6 bar.
Close the bypass valve if the operating pressure constantly
exceeds 6 bar. Otherwise the material at the opening will be worn
because of the high liquid velocity.

8.1 Shaft seal run-in

The seal faces are lubricated by the pumped liquid, meaning that
there may be a certain amount of leakage from the shaft seal.
When the pump is started up for the first time, or when a new
shaft seal is installed, a certain run-in period is required before
the leakage is reduced to an acceptable level. The time required
for this depends on the operating conditions, i.e. every time the
operating conditions change, a new run-in period will be started.
Under normal conditions, the leaking liquid will evaporate.
As a result, no leakage will be detected.
However, liquids such as kerosene will not evaporate.
The leakage may therefore be seen as a shaft seal failure.

9. Maintenance

Warning
Before starting work on the pump, make sure that
the power supply has been switched off and that
it cannot be accidentally switched on.
Pump bearings and shaft seal are maintenance-free.
Motor bearings
Motors without grease nipples are maintenance-free.
Motors with grease nipples should be lubricated with a high-
temperature, lithium-based grease. See the instructions on the
fan cover.
In the case of seasonal operation (motor is idle for more than six
months of the year), we recommend you to grease the motor
when the pump is taken out of operation.
Depending on the ambient temperature, the motor bearings must
be replaced or lubricated according to the table below. The table
applies to 2-pole motors. The number of operating hours stated
for bearing replacement is a guideline only.
Bearing replacement interval [operating hours]
Motor size
[kW]
40 °C 45 °C
0.37 - 0.55 18000 -
0.75 - 7.5 20000 15500
Lubrication interval [operating hours]
Motor size
[kW]
40 °C 45 °C
11 - 18.5 4500 3400
Intervals for 4-pole motors are twice as long as those for 2-pole
motors.
If the ambient temperature is lower than 40 °C, bearings must be
replaced/lubricated at the intervals mentioned under 40 °C.
14
50 °C 55 °C 60 °C
- - -
12500 10000 7500
50 °C 55 °C 60 °C
2500 1700 1100

10. Frost protection

Pumps which are not being used during periods of frost should be
drained to avoid damage.
Drain the pump by loosening the vent screw in the pump head
and by removing the drain plug from the base.
Warning
Pay attention to the direction of the vent hole and
take care to ensure that the escaping water does
not cause injury to persons or damage to the
motor or other components.
In hot-water installations, pay special attention to
the risk of injury caused by scalding hot water.
Do not tighten the vent screw and replace the drain plug until the
pump is to be used again.
CRT 2 and 4
Before replacing the drain plug in the base, screw the bypass
valve out against the stop. See fig. 18.
Fig. 18 Location of drain plug and bypass valve
Fit the drain plug by tightening the large union nut followed by the
bypass valve.
CRT 8 and 16
Fit the drain plug in the base.

11. Service

It is advisable to repair pumps with motors of 7.5 kW and up at
pump site. Necessary lifting equipment must be available.
If a pump has been used for a liquid which is
Note toxic or injurious to health, the pump will be
classified as contaminated.
If Grundfos is requested to service the pump, Grundfos must be
contacted with details about the pumped liquid, etc. before the
pump is returned for service. Otherwise Grundfos can refuse to
accept the pump for service.
Possible costs of returning the pump are to be paid by the
customer.
However, any application for service (no matter to whom it may
be made) must include details about the pumped liquid if the
pump has been used for liquids which are toxic or injurious to
health.

11.1 Service kits and manuals

See www.grundfos.com (WebCAPS), WinCAPS or Service Kit
Catalogue.
Drain plug
Bypass valve