ELAP LQRQ VD3 Series User manual

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PANEL DIGITAL READOUTS
SERIES VD3 LQRQ
Versions VD30 VD30TF VD31 VD31TF
Digital readouts series VD3 LQRQ can be coupled to
linear or rotary potentiometer transducers with
resistive value ranging between 1 and 100 Kohm.
The value of the measured magnitude can be
adjusted from zero up to the instrument full range
scale value.
The number of decimal digits can be selected by
means of internal bridges. All instruments are
provided with extractable terminal board.
Specifications:
Power supply
24 Vac or 115/230 Vac ±10% 50/60Hz
Absorption
3 VA
Display
7-segment LED display h. 12.7 mm
Display range
VD30 -999 ÷ 999
VD31 -1999 ÷ 1999
Decimal digits
0, 1, 2, 3
Polarity
automatic with ± sign indication
Resolution
VD30 0.1% FSR value
VD31 0.05% FSR value
Accuracy
± 0.05% of the calibration value
Operating temperature
0 ÷ 45° C
Voltage provided by the instrument for
the transducer supply
2.5 Vdc steady
Panel cut off dimensions
92 x 45 mm
Front case dimension
48 x 96 mm
Installation and maintenance
Connect the instrument as described in the enclosed
diagram C2421; check that the power supply
corresponds to the label indication.
In order to change the position of the decimal point
extract the circuit from the rear case after removing
the restrained frame; then select the jumper as
required.
Configuration
In order to configurate the instrument it is necessary
to plug it off, take out the extractable terminal board,
remove the frame placed back of the instrument
(levering on the proper housings) and remove the
circuit completely from its holder.
By positioning the jumpers as described in the
connection diagram tables it is possible to adjust the
decimal point position, the input gain value, and the
full range scale excursion.
After positioning the jumpings it is highly
recommended to close the instrument before
energising it.
Full range scale adjusting
The instrument is normally supplied with adjustment
value = 20 digits.
Use the adjusting trimmers P1 and P2 to set the
display values as needed. In case you cannot
achieve the needed values, it is necessary to set the
FRS at the next superior value.

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Gain
The instrument is normally supplied with gain value
x1; setting gain x2 or x4 allows to reach the FRS with
half or one fourth of the max potentiometer
excursion.
Connecting the transducer with one end to zero
With this configuration the instrument displays zero
when the cursor is next to one of the transducer
ends. The ends are linked to terminals 4 and 7 while
the cursor is connected to terminal 8.
Connecting the transducer with mid-stroke zero
With this configuration the instrument displays zero
when the cursor is at the transducer mid-stroke. The
transducer ends are linked to terminals 4 and 6 while
the cursor is connected to terminal 8.
Calibration
We advise to adjust the readout in the following way:
Set the machine axis to zero and adjust the display
indication to zero by means of the trimmer P1
placed on the front case
Set the machine axis to its maximum excursion
and adjust the display at the requested value by
means of the display range trimmer P2 placed on
the rear case.
Repeat the operation to achieve the best measuring
accuracy.
The display value increasing direction can be
inverted by inverting the transducer ends.
REMARK:
The readout type TF has both trimmers placed on
the front case, which must be removed to calibrate
the instrument. To remove the front case slightly
lever between the front case and the frame with a
small flat screw-driver.
MAINTENANCE
Check the terminals clamping regularly.