Accu-Turn 1250 User manual

SERVICE
MANUAL
MODELS 1250, 1450, 1550, 1650, 1850

Model1250
WheelBalancer

M 0495 - 1
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Special maintenance M
CONTENTS page
1 - CHANGING SUPPLY VOLTAGE ...................................................................................................................................3
2 - CHECKING OF THE RIM DISTANCE GAUGE .............................................................................................................3
3 - ASSEMBLY OF THE PIEZO MEASURERS ..................................................................................................................4
4 - LOGIC TROUBLE SHOOTING SEQUENCE ................................................................................................................5
5 - POWER SUPPLY LAYOUT DIAGRAM .......................................................................................................................6
6 - REPLACING THE POWER BOARD .............................................................................................................................7
7 - FUNCTION AND PRECISION CHECK .........................................................................................................................8
8 - WHEEL MEASUREMENT AND PRESETTINGS ON THE BALANCING MACHINE ................................................10

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1 - CHANGING SUPPLY VOLTAGE
(See recommended spare parts lists and power layout diagram)
The wheel balancer can operate at 115 V - 50/60 Hz or 230V - 50/60Hz.
To change the supply voltage, proceed as follows:
1) Replace the motor.
2) Replace the entire power board or else modify the board as follows:
A) Replace the capacitor
B) Replace the transformer.
2 - CHECKING OF THE RIM DISTANCE GAUGE
Check that the ruler used for measuring the DISTANCE of the wheels reads 21,5 cm as measurement of the distance
from the adapter plane. If the graduated scale is changed, position it with the line indicating 21,5 cm at the fixed limit
(reading point) when the gauge tip coincides with the adapter plane.
Reading point : 21,5 cm Adapter plane

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4
5
3
2
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3 - ASSEMBLY OF THE PIEZO MEASURERS
Problems of excessive compensation and out-of-phase sometimes depend on a fault in the piezo measurers.
To replace them, proceed as follows:
1. Remove the weight shelf.
2. Remove nuts 1 and 2 with relative cup springs and washers.
3. Back-off screws 3, 4, 6 and 5 then disassemble the various parts.
4. Reassemble the various parts without tightening the nuts being careful to follow the correct sequence.
N.B.: Mount the piezo units in accordance with the position of the coloured wires shown in the drawing.
5. Keeping the spindle perfectly aligned, tighten the nuts 5 and 6 with a spanner, and nuts 3 and 4 by hand (by half a
turn with the spanner if necessary).
6. Refit the washers, cup springs and nuts 1 and 2. Tighten the nuts fully in order to fully regain the elasticity of the cup
springs, then loosen them by half a turn. This will automatically ensure correct preloading on the piezo (a torque
wrench can be used set to 400 kg. cm.).
7. Cover the piezo units with a generous layer of silicone.(N.B.: For correct operation, insulation of the piezo
crystals should be greater than 50 Mohm).
8. Reassemble the various parts.
9. Again carry out the automatic calibration.
yellow
blue
yellow
white

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4 - LOGIC TROUBLE SHOOTING SEQUENCE
Is the fuse on the computer board
in a good state?
NO
YES
Replace the computer board
Replace the fuse and switch on
Is the fuse working?
Disconnet CN1 on the power board.
Again replace the fuse and switch on.
Is the fuse working?
Does the voltage across
points 3-4 on the transformer
connector correspond to that
shown in the layout diagram?
YES
Check that the transformer primary be
energized with the mains voltage and
that there is not damage in the wiring.
If everything is OK, replace the transfor-
mer.
YES
NO
Is the position sensor working?
(see SELF DIAGNOSTICS)
Replace the position
sensor board.
NOTE : Do not remove
the mounting brackets.
Replace the computer board
YES
NO
NO
YES
Replace the power
board
Is the fuse working?
NO

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5 - POWER SUPPLY LAYOUT DIAGRAM
( 230 V connection )

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6 - REPLACING THE POWER BOARD
( check voltage )