Grundfos TP Series, Installation And Operating Instructions Manual

Page: 15 / 212

English (GB)
15
9. Start-up
9.1 Priming
Closed systems or open systems where the
liquid level is above the pump inlet:
1. Close the discharge isolating valve and loosen
the air vent screw in the motor stool, see fig. 4.
Fig. 4 Air vent screw
2. Slowly open the isolating valve in the suction
pipe until a steady stream of liquid runs out of the
vent hole.
3. Tighten the air vent screw and completely open
the isolating valve(s).
Open systems where the liquid level is below the
pump inlet:
The suction pipe and the pump must be filled with
liquid and vented before the pump is started.
1. Close the discharge isolating valve and open the
isolating valve in the suction pipe.
2. Loosen the air vent screw.
3. Remove the plug from one of the pump flanges,
depending on the pump location.
4. Pour liquid through the priming port until the
suction pipe and the pump are completely filled
with liquid.
5. Replace the plug and tighten securely.
6. Tighten the air vent screw.
The suction pipe can to some extent be filled with
liquid and vented before it is connected to the pump.
A priming device can also be installed before the
pump.
9.2 Checking the direction of rotation
Do not start the pump to check the direction of
rotation until it has been filled with liquid.
The correct direction of rotation is indicated by
arrows on the pump.
9.3 Starting
1. Before starting the pump, completely open the
isolating valve on the suction side of the pump
and leave the discharge isolating valve almost
closed.
2. Start the pump.
3. Vent the pump during starting by loosening the
air vent screw in the motor stool until a steady
stream of liquid runs out of the vent hole, see
fig. 4.
4. When the piping system has been filled with
liquid, slowly open the discharge isolating valve
until it is completely open.
Measure motor current consumption and compare
the result with the nominal current stated on the
motor nameplate. In the event of motor overload,
throttle the discharge isolating valve until the motor
is no longer overloaded.
It is advisable always to check the motor current
consumption during starting.
9.4 Frequency of starts and stops
The pump should not start more than 20 times per
hour.
Caution
Do not start the pump until it has been
filled with liquid and vented.
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, special attention
should be paid to the risk of injury
caused by scalding hot water.
T
M
02
69
67
20
0
3
Air vent screw
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, special
attention should be paid to the risk of
injury caused by scalding hot water.
Caution
If the pumps are fitted with motors with
outputs selected on the basis of a
specific maximum flow rate, the motors
may be overloaded if the differential
pressure is lower than anticipated.