Wilo -NL 32-125 Einbau- Und Betriebsanleitung Seite 29

WARNING!
Uncompleted gas purging can reduce signifi-
cantly the lifetime of the pump.
8.5 Electrical connection
The motor must be connected at set out in the
circuit diagram in the terminal box.
8.6 Checks before switching-on
Before switching-on of pump, make sure that
nobody can be endangered by this starting.
Before switching-on the pump unit, the follo-
wing points should be checked:
1. Is all pipework connected and are the unions
tight?
2. Has the shaft seal been installed?
3. Are the supply lines, if any, to the shaft seal
open?
4. Is the coupling aligned exactly?
5. Is the pump including the pipework filled proper-
ly?
6. Is the shut-off valve in the discharge line
closed?
7. Is the shut-off valve in the suction line comple-
tely opened?
8. Is the motor ready for operation?
9. Is the direction of rotation of the motor correct?
(Check by running the motor for a short time)
10. Is the gland finger slightly tight?
Fig. 7
8.7 Start-up operation
For starting proceed as follows:
• Open fully the valve on the suction side.
• Close the valve on the discharge side.
• Switch on the motor.
• Check the pressure gauges at the pressure mea-
suring points If the pumping pressure does not
increase consistently with increasing speed,
switch off the motor again and vent the pump
one more.
• After reaching operating speed, regulate the
operating point of the pump by adjusting the
valve in the discharge line (see technical data for
permissible range of operation).
• For "running in" the packing, the gland should be
tightened only slightly (even in the case of
considerable leakage initially). After approx.
30 minutes tighten the gland to such an extent
that it leaks only slightly. Check it several times,
until leakage from the packing is about 20 to 40
drops a minute. In extreme operating conditions
and high temperatures this rate may be higher.
Pumping against a closed valve in the discharge
line is permitted only if a minimum output via a
WILO AG 09/2007
bypass line is guaranteed.
If the installation is protected with a pressure
relief valve, ensure that the pressure setting do
not exceed the resistance of the pump casing.
The alignment of the pump / motor must be
checked when the functioning temperature is
arisen.
8.8 Switching frequency
The permissible switching frequency is listed in
the table bellow accordingly the pump size:
Pump size
32-125, 32-160, 32-200, 32-250,
40-125, 40-160, 40-200, 40-250,
50-125, 50-160, 50-200, 65-125,
65-160, 65-200, 65-250, 80-160,
80-200, 80-250,100-160,
100-200, 100-250, 100-315,
125-200, 150-200, 150-250
40-315, 50-250, 50-315, 65-315,
80-315, 80-400, 100-400,
125-250, 125-315, 125-400,
150-315, 150-400, 150-500,
200-250, 200-315, 200-400,
200-500, 250-300, 250-315,
250-400, 250-500, 300-400,
300-500
8.9 Special instructions
During operation the following points must be
checked:
- Ensure that the pump runs without vibration.
- Control the liquid level in the suction line and/or
inflow tank.
- Control the bearing temperature (max. tempera-
ture 100 °C).
Shaft seal
Execution with stuffing box:
For correct operation of the shaft seal a slight
leakage (20 - 40 drops per minute) is essential. If
the leakage is reduced too much by retightening
the packing, the packing rings will be destroyed.
Execution with mechanical seal:
During running-in slight leakage may occur. If
the pump is equipped with an external flush,
quench or heating, the flush, quench or heating
supply has to be switched on before the pump is
started. The mechanical seal must be allowed to
cool before the next re-start.
CAUTION!
For executions with stuffing box: If the leakage
increases considerably and cannot be adjusted
by retightening the gland, the packing is worn
and must be replaced by a new one.
For executions with mechanical seal: If the ini-
tial leakage does not disappear within 5 minutes
of operation, stop the pump, dismantle the seal
and check for damage of the seal faces and auxi-
liary sealing.
Maximum frequency of
switching on per hour
15
8
English
29