Primary Training
Calibration
3.2.3 Input ranges
VOLTAGE CURRENT
Max. input value
Max. input value
Range
AC RMS
DC
Range
AC RMS
DC
2V
2V
2.8284V
2/SH
2/Shunt A
2.8284/shunt A
5V
5V
7.0710V
5/SH
5/Shunt A
7.0710/shunt A
12V
12V
16.9700V
12/SH
12/Shunt A
16.9700/shunt A
30V
30V
42.4260V
30/SH
30/Shunt A
42.4260/shunt A
110V
110V
155.5600V
110/SH
110/Shunt A
115.5600/shunt A
220V
220V
311.1200V
220/SH
220/Shunt A
311.1200/shunt A
Additionally, on a 424-03 board, you can select the divide by 2 jumper for any
channel, and halve the above listed maximum input values.
For current inputs, a shunt is added in parallel with the input. The current ranges are
equal to the voltage ranges in Volts divided by the shunt values in Ohms.
Unless special shunts are used, the maximum current for 1s is 100 A RMS for the
0.1
Ω
shunts and 30 A RMS for the 0.47
Ω
shunts.
For current loops in the range of 0-20 mA, range 1 will be used.
3.2.4 Setting input ranges
To change input voltage ranges (V RMS), move to the 'RANGE' column by using the
vertical arrow. Press the spacebar to toggle through the possible ranges. Check that
the input range selectors J1 ... J4 are correctly placed on the 5424 isolation cards.
For current inputs, choose a 'RANGE' with the '/SH' suffix, and enter the shunt value
in the 'SHUNTS' column.
Note 1
: For voltage inputs, the 'SHUNTS' values must always be left at zero.
For current inputs, the 'SHUNTS' values must never be equal to zero.
Note 2
: For shunt values higher than 10 ohms, you must introduce the resulting
value of the shunt in parallel with the input impedance of the isolation
card, which is 10 K ohms on range 1.
Example
: if the shunt value is 143 ohms, you must introduce a value
of 143//10000 = 141 ohms.
Note 3
: During the initial calibration of a 623 card, all the ranges are initialized
to an 'OFF' value. This value has no physical meaning, but disables the
calibration functions. This forces the operator to select range values,
and to check the corresponding jumpers on the 424 isolation cards, in
order to calibrate the channels.
9200-14 REV E
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