Innotech Genesis V4 System User Manual
Page 71
Installation Instructions for Innotech Genesis Systems
Edition 011100
4-16
CURRENT
ACROSS 500
I05
0 – 5mA
0 – 2.5Vdc
I20
4 – 20mA
2 – 10Vdc
TD1
0 – 250 A
0 – 0.125Vdc
TD2
0 – 500 A
0 – 0.25Vdc
Inputs associated with the P20 AISC are 4 – 20mA loop-powered inputs. These inputs
CANNOT be conveniently checked in the same manner as the other current inputs
without applying power to the Genesis unit before it is safe to do so. Loop powered
input wiring is checked by using a voltmeter to ascertain that there is no stray voltage
present at the input terminals. The input wiring is then visually inspected for proper
connection.
Following are procedures for performing current checks:
a.
Ensure all AISCs have been removed and no power is applied to the Genesis unit.
b.
For analogue inputs associated with P20 AISCs go to Step
i.
c.
Temporarily connect a 500-Ohm (or suitable value) resistor across the terminals of
the first current input channel to be checked.
d.
Set a digital voltmeter to indicate Vdc. Set the range for the expected voltage value
shown in the matrix above.
e.
Connect the voltmeter across the analogue input terminals observing polarity. If
necessary, reduce the voltmeter range to obtain an accurate reading.
f.
Ensure the measured voltage is within the expected range and of the correct polarity.
If not, check the analogue input wiring for faults/errors
g.
Remove the temporary resistor connected in Step c. above.
h.
Repeat Steps b. through g. for the remaining inputs associated with the AISC models
noted above.
i.
To check inputs for the P20 type AISC, connect a digital voltmeter across the input
terminals. DO NOT connect a resistor across the terminals. Reduce the voltmeter
range to the lowest setting practical. If voltage is present at the input terminals, it
indicates a fault or improper wiring of the input circuit.
j.
Visually inspect the wiring of the P20 type analogue input. Ensure that all wiring
conforms to the associated wiring diagram. Ensure correct polarity is maintained
throughout.