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Important!: For the choice of start-up/shutdown and overloa-
ding protection electrical appliances refer to the technical data,
electrical features, nominal current and start-up current. Also
always choose delayed magnetic-circuit breakers, to prevent
release during start-up time, which may be longer in low envi-
ronmental temperatures.
On customer request the electric vibrator can be equipped with
anticondensation heater; the heater can be recommended in case
of ambient temperature lower than –20°C and intermittent duty in
high humidity ambients, to avoid condensation inside the unit. For
electrical connection of the heater see diagram in page 107.
3.6 POWER SUPPLY WITH FREQUENCY VARIATOR
All of the vibrators can be powered with a 20Hz frequency variator
(inverter) up to the plate frequency, with constant torque functioning
(rather with linear course of the Volt-Hertz curve) using a PWM (Pulse
Width Modulation) variator.
The ITV-VR high variable frequency vibrators are designed to be
powered by frequency variators up to 100Hz.
The ITVAF high fixed frequency vibrators are designed to be powe-
red with fixed frequency according to the technical specifications of
each type.
SECTION 4 –
Use of the vibrator
4.0 PRELIMINARY CHECKS
ATTENTION: Controls must be carried out by specialised staff.
During disassembly and re-assembly of protective parts (ter-
minal box cover and weight cover), remove the power supply
from the vibrator.
Check current draw.
- Remove the cover from the terminal board compartment.
- Power the vibrator.
- Use an amperometer clamp to verify (Fig. 28, page 10), on each
phase, that the current draw does not exceed the value indicated
on the identification plate.
ATTENTION: Avoid touching or allowing anyone to touch live
parts such as the terminal board.
If the current draw exceeds that stated on the plate:
- Check that the flexible system and the vibrating machine framework
are in compliance with the regulations for correct application.
- Reduce force (centrifugal force) by adjusting the weights. Reduce
them until the value of absorbed current corresponds to that stated
on the identification plate.
Remember to allow the vibrators to function for brief periods of
time during set-up. This prevents damage to the vibrator and
structure in the case of anomalies.
Once the indicated controls have been carried out close the
cover definitively.
MVSI-MP special series models with 600 - 720 rpm are equip-
ped with permanent magnet device to ensure shutdown of the
vibrators with weight always in phase.
Check direction of rotation:
In applications where direction of rotation must be ascertained (B
Fig. 29, page 10).
- Remove a weight cover (A Fig. 29, page 10);
- Wear protective glasses;
- Power the vibrator for a brief period of time;
ATTENTION: in this phase ensure that no-one can touch or be
struck by the rotating weights.
- If the direction of rotation must be inverted, act on terminal board
connections, after having removed the power supply from the
vibrator.
- Reposition the covers, ensuring that the seals (OR) are correctly
positioned and tighten the screw fastener.
4.1 VIBRATION FORCE ADJUSTMENT
ATTENTION: This operation must be carried out exclusively by
specialised staff with the power supply disconnected.
- To adjust vibration intensity it is necessary to remove the weight
covers.
- It is usually necessary to adjust the weights in the same direction
in the two ends (Fig. 30, page 10). To allow exact adjustment of
the weights, the vibrators are equipped with a patented system
that prevents the adjustable weight to turn in the wrong direction
(Fig. 31, page 10).
- Unscrew the mobile weight screw fastener or nut (Fig. 32, page 10).
The adjustable weights positioned at the two ends of the shaft must
be positioned in a way to read the same value on the reference
percentage scale. The weights positioned at the two sides of the
vibrator can only be adjusted on two different values for particular
machines and for special uses.
- For the MVSI-TS and MVSI-ACC series adjustment must be carried
out as for the corresponding MVSI series motors.
- Once the eccentric weight has been taken to the desired value
tighten the screw fastener or nut using the dynamometric wrench
(Fig. 33, page 10) and repeat the same operation on the opposite
weight (see the table on page 105 for coupling torques)
ATTENTION: For every ITV-VR adjustment of the weight (number
N
of fixed weights per side, number N
f
per side and maximum adjustment percentage P
adjustable weights) and connection to the terminal board (star
Y or ∆ Delta) are linked to the desired power supply frequency
variation field (Hz) – page 86 (refer to terminal board connection
diagram sheet). Contact Italvibras technical staff for different
adjustments.
- Once the operation on the two sides has been carried out, re-mount
the covers on the screws and washers paying attention that the
seals are correctly positioned in their houses (Fig. 39).
4.2 START-UP AND SHUTDOWN OF THE VI-
BRATOR DURING USE
Start-up takes place by always and only acting on the power supply
switch by positioning it in the ON position (insertion of the power
supply network).
The vibrator works.
Stop the vibrator by always and only acting on the power supply
switch by positioning it in the OFF position (disconnection of the
power supply network).
SECTION 5 –
Maintenance of the vibrator
ITALVIBRAS vibrators have no particular need for maintenance.
Only authorised technicians can intervene on the parts that
make up the vibrator.
Before carrying out maintenance on the vibrator wait until the
temperature of the vibrator case is not above +40° C and ensure
that the electrical power supply has been disconnected.
If parts must be replaced, only ITALVIBRAS original spare parts
must be used.
20
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of adjustable weights
r
% of the
max