ENGLISH
21
DOL , stator and
autotransformer starting
Motor cables are marked with
letters U1, V1, W1 and have
to be connected to control
panel terminals, respectively:
U1, V1, W1 for clockwise
rotation
(seen
from
motor/pump coupling). For
counterclockwise
rotation,
reverse two of the cables.
6.5 Further instructions for six-cables
motors terminals connection
Six cables motors can be
started with a Star/Delta
starter only if main voltage is
at least equivalent to the
motor minimum rated voltage.
To obtain the correct rotation
direction, find main terminals
L1, L2 and L3 as previously
described.
7. COMMISSIONING AND STARTUP
7.1 Startup
–
Start the pump with gate valve half opened to
check rotation direction. When the water starts
flowing, close further the gate valve: pressure
rating should be higher than rated pressure value.
If this is not the case, the rotation direction is
wrong. Reverse two motor phases to restore the
correct rotation direction.
–
The pump should not run in the wrong sense for
more than 3 minutes.
Close then the gate valve to
about the half of its full opening and leave the
pump running for a minute. Stop then the pump
for five minutes to allow the dissolution of air
bubbles which, if present, might endanger shaft
lubrication.
–
Start the pump and gradually open the delivery
gate valve till the water shows free of sand, or till
the suspended sand has dropped to a sufficiently
low percentage (40 g/m³).
–
Before definitively commissioning the pump,
remove starter fuses and check the electric circuit
integrity with an ohm-meter to make sure there
have been no damages when lowering the pump
in the well.
If the results are negative, lift the group again and
check it thoroughly.
–
For three-phases units, the electric resistance value
should be nearly the same for each phase.
–
Check insulation resistance to the ground (i.e.
between cable end and discharge pipe) using a
megahoms-meter. Minimum value to the ground for
a new pump is 10 megahoms with cold motor.
–
However, if some misfunctioning is detected during
startup, stop immediately the pump and investigate
the problem.
–
Check also that the pump runs within its operating
limits and that voltage rates reported on control
panel do not exceed motor nameplate rated values.
–
If necessary, partially close gate valve or adjust the
intervention of pressure switches.
The system should be fully completed
before starting the pump, especially for
what concerns electrical, mechanical and
hydraulical components.
All safety systems must be correctly
operating.
The pump cannot run for more than 3
minutes with the gate valve closed to
avoid overheating of the unit.
7.2 Operation
The max. number of possible startups / hour depends
from motor power and starter type.
Up to 100 Hp = 10 startups / hour
100/200 Hp = 8 startups / hour
above 200 Hp = 5 startups / hour
If the pump does not start, avoid insisting without
having before investigated the reason.
All motors can afford ÷ 5% voltage deviation from
rated voltage values.
7.3 Running tests
In case of pump misfunctioning, perform the following
tests to find out the probable reasons:
FIRST TEST
–
Close fully the gate valve.
–
Note at startup the AMPS absorbed.
–
Note during operation.
–
Note pressure as reported by the pressure gauge
on delivery.
–
Note vertical distance between water level and the
gauge dial center.
Connection
Electrical
equipment
Connection
Electrical
equipment
