Electrical Connection; Motor Protection; Start-Up; Checking Of Direction Of Rotation - Grundfos AP80 Montage- Und Betriebsanleitung

5. Electrical connection

The electrical connection should be carried out in accordance
with local regulations.
The operating voltage and frequency are marked on the name-
plate. Voltage tolerance: ±10% of the voltage stated on the name-
plate (±5% for explosion-proof pumps). Make sure that the motor
is suitable for the electricity supply available at the installation
site.
The pump must be connected to an external mains switch.
• AP100.100.24 is for direct-on-line starting only. Other pump
types are prepared for star-delta starting, i.e. both ends of the
motor windings are accessible through the motor cable, see
fig. 1.
• T1 and T3 are connected to the standard set of temperature
sensors.
• T1 and T2 are connected to the extra set of temperature sen-
sors in explosion-proof pumps.
• S1 and S2 are connected to the moisture sensor in the oil
chamber.
• S3 and S4 are connected to the moisture sensor in the cham-
ber below the top cover.
Fig. 1
PE U U V V W W
1 2 1 2 1
S S S S
1 2 3

5.1 Motor protection

All pumps are supplied with 10 metres of cable and a free cable
end. The pumps must be connected to a separate pump control-
ler with motor starter.
The stator windings incorporate temperature sensors which cut
out the motor in case of overtemperature.
Moisture sensors have been incorporated in the oil chamber be-
tween the motor and the pump housing as well as at the terminal
board under the top cover. The moisture sensors will cut out the
motor in case of water penetration.
The temperature and moisture sensors are connected to the
monitoring cable. The temperature sensors and the tripping units
of the moisture sensors must be connected to the safety circuit of
the separate pump controller.
Note: The separate motor starter/control box in standard version
must not be installed in explosive environments.

6. Start-up

1. Check the oil level in the oil chamber.
2. Remove the fuses and check whether the impeller can rotate
freely.
3. Check whether the monitoring units, if used, are operating sat-
isfactorily.
4. Do not start the pump until the system has been filled with liq-
uid and vented. Make sure that the pump is submerged in the
liquid, open the isolating valves, if fitted, and check the setting
of the level switches.
5. In dry installations, the cooling jacket fitted to the pump must
be vented separately.
2
T
1
+10°C
T
2
T
3
4

6.1 Checking of direction of rotation

The direction of rotation should be checked every time the pump
is connected to a new installation.
Check the direction of rotation as follows:
1. Start the pump and check the quantity of water or the dis-
charge pressure.
2. Stop the pump and interchange two of the phases to the mo-
tor.
3. Start the pump and check the quantity of water or the dis-
charge pressure.
4. Stop the pump.
Compare the results taken under points 1 and 3, and the connec-
tion which gives the larger quantity of water or the higher pres-
sure is the correct direction of rotation.

7. Maintenance and service

Before starting work on the pump, make sure that the
electricity supply has been switched off and that it
cannot be accidentally switched on. Furthermore, all
rotating parts must have stopped moving.
Maintenance and service must be carried out by specially trained
persons.
Before carrying out maintenance and service, it must be ensured
that the pump has been thoroughly flushed with clean water.
Rinse the pump parts in water after dismantling.
When unscrewing the inspection screw of the oil
chamber, please note that pressure may have built up
in the chamber. Do not remove the screw until the
pressure has been fully relieved.
Pumps running normal operation should be inspected at least
once a year. If the pumped liquid is very muddy or sandy or if the
pump is operating continuously, the pump should be inspected
every 1000 operating hours.
When the pump is new or after replacement of the shaft seals,
check the oil level after one week of operation.
For long and trouble-free operation of the pump, the following
points should be checked regularly:
• Power consumption
• Oil level and oil condition
The oil becomes greyish white like milk if it contains water.
This may be the result of a defective shaft seal. The oil should
be replaced after 3000 operating hours.
Note: Used oil must be disposed of in accordance with local
regulations.
The oil chamber contains 1.7 litres Shell Ondina 15 oil.
• Cable entry
Make sure that the cable entry is watertight and that the ca-
bles are not bent sharply and/or pinched.
• Pump parts
Check the impeller, pump housing, neck ring, etc. for possible
wear. Replace defective parts.
• Ball bearings
Check the shaft for noisy or heavy operation (turn the shaft by
hand). Replace defective ball bearings.
A general overhaul of the pump is usually required in case of
defective ball bearings or poor motor function. This work must
be carried out by an authorized GRUNDFOS service work-
shop.
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