Starting; Shaft Seal Run-In; Frequency Of Starts And Stops; Maintenance And Service - Grundfos TP Installation And Operating Instructions Manual

7.4 Starting

1. Before starting the pump, completely open the
isolating valve on the inlet side of the pump and
leave the isolating valve on the outlet side almost
closed.
2. Start the pump.
3. Vent the pump during starting by loosening the
vent screw in the motor stool until a steady
stream of liquid runs out of the vent hole. See fig.
15.
Warning
Pay attention to the direction of the vent
hole and make sure that the escaping
liquid does not cause injury to persons or
damage to the motor or other components.
In hot-liquid installations, pay special
attention to the risk of injury caused by
scalding hot liquid.
In cold-liquid installations, pay special
attention to the risk of injury caused by the
cold liquid.
4. When the pipe system has been filled with liquid,
slowly open the isolating valve on the outlet side
until it is completely open.

7.5 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.
14

7.6 Frequency of starts and stops

Maximum number of starts per hour
Frame
Number of poles
size
2
56-71 100
80-100 60
112-132 30
160-180 15
200-225 8
250-315 4
• On twin-head pumps, the duty and standby
pumps must be alternated on a regular basis, i.e.
once a week, to ensure an even distribution of
the operating hours on both pumps. Pump
change can be effected either manually or
automatically by installing a suitable pump
controller.
• If twin-head pumps are used for pumping
domestic hot water, the duty and standby pumps
must be alternated on a regular basis, i.e. once a
day, to avoid blocking of the standby pump due to
deposits (calcareous deposits, etc.). We
recommend automatic pump change.

8. Maintenance and service

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.
Make sure that the escaping liquid does
not cause injury to persons or damage to
the motor or other components.
In hot-liquid installations, pay special
attention to the risk of injury caused by
scalding hot liquid.
In cold-liquid installations, pay special
attention to the risk of injury caused by the
cold liquid.

8.1 Pump

The pump is maintenance-free.
If the pump is to be drained for a long period of
inactivity, inject a few drops of silicone oil on the
shaft between the motor stool and the coupling. This
will prevent the shaft seal faces from sticking.
4 6
250 350
140 160
60 80
30 50
15 30
8 12