Higher Voltage : Y Connection; Y /  Starter; Use Of A Frequency Inverter; Start-Up - Samson NESE Manuel D'installation Et Mise En Service

7.3.3 HIGHER VOLTAGE : Y CONNECTION
Voltage : U3
7.3.4 Y /  STARTER :
Grounding of the complete pumpset will be performed with
special care. Earthing will avoid any electrostatic accumulation in
components of the pumpset. Each part of the pumpset should be
connected to earth with a correctly calibrated bonding strap or cable
(motor winding, motor frame, coupling guard, pump baseframe).
7.4 USE OF A FREQUENCY INVERTER
When pump is used with a variable speed drive, make sure that
the frequency inverter instructions and operating manual is
available and known.
The electric motor that is supplied with the pump may be connected
under conditions to a VSD. Variable speed will be used to reach pump
required duty point on site. To ensure a reliable use of the equipment a
few precautions should be taken :
Electrical requirements :
 Variable frequency drive will not generate voltage peak higher than
850V (motor phases isolation) and dU/dt values higher than 2500 V/µs
(winding isolation). If those values can be reached, a filter should be
installed : ask inverter manufacturer for proper selection and motor
manufacturer for limit values.
 Choose a vector control inverter or use a quadratic V/F control
inverter.
 Check that motor nominal voltage is never exceeded.
Power supply cable should comply to ATEX regulation. Ensure that
motor winding is equipped with CTP temperature sensors inside.
A physical barrier should separate power supply cables and low
voltage cables to avoid analog signal distortion.
Hydraulic requirements :
 A dedicated suction pipe should be dedicated to each pump used with
a negative suction head (suction lift).
 Check that the pump NPSH
at minimum speed is always lower than
R
system NPSH .
A
Mechanical requirements :
 Lower speed should not fall under 40% of pump nominal speed to
avoid any vibrations and an unstable flow.
The harmonic currents that are created by the VSD pass through
motor ball bearings. Standard ball bearings can be used up to
55KW. For higher installed power (see engraved power on motor name
plate), the motor should be equipped with isolated ball bearings
(specific ball bearing) or with isolated bearing housing (and standard ball
bearing).
13
8 START‐UP
8.1 PRE‐COMMISSIONING
If the pump is installed in a potentially explosive atmosphere or
when dangerous or polluting fluids are pumped, it is advised (Zone
2) or requested (zone 1) to install additional protection devices.
Check following points :
 Pump flow is always higher than authorized continuous minimum flow,
 Pump never runs dry,
 Normal leakage of the shaft seal is controlled,
 Surface temperature bearings housings is lower than the maximum
admissible surface temperature in selected ATEX zone,
 Pressure on discharge side of the pump is lower than pump maximum
allowable working pressure.
 Set alarm and stop trips of sensors.
In every cases check :
 Quality of electrical connections,
 Protection devices are installed,
 Auxiliary piping are connected,
 Flanges connections,
 Suction line and pump casing are filled with fluid,
 Motor direction of rotation is correct,
 Coupling alignment is correct,
 Oil level was checked and greasing of ball bearings has been done,
 Coupling guard is installed.
8.2 FILLING / VENTING
Before the very first start‐up, pump casing and suction line must be filled
with fluid (depending on piping system a vacuum pump may have to be
used).
Pump casing should be perfectly vented to avoid that the
mechanical seal runs dry.
Take precautionary measures when manipulating dangerous, hot
or polluting fluids. Wearing individual protective devices is
necessary. The operator must know the potential hazards.
The mechanical seal housing should be completely vented. A vent valve
is located on the top of the bearing bracket.
Burn hazard when manipulating the pump. Vent valve or vent
screw should be opened slowly and left open until pump is
completely vented. Then close venting device. Use of protections and
pincers is necessary.
Complete venting may take a long time. An incomplete venting of
pump could drive to a rapid destruction of the mechanical seal and
the internal shaft bearing.
8.3 START‐UP
If a barrier fluid, flushing fluid, cooling fluid or a heating fluid is
used, check that auxiliary systems are activated and working
correctly before pump start‐up.
 Close isolating valve on pump discharge side.
 Open all valves in suction line.
 Proceed to pump priming (if not already done). Pump casing and
suction pipe should be completely filled with fluid.
ENGLISH