Innotech Genesis V4 System - Manual (Page 72)

Installation Instructions for Innotech Genesis Systems
Edition 011100 4-17
4-1.2.4.3. Resistance Checks. This paragraph contains procedures for checking
analogue inputs associated with AISC Models TH1 through TH9. Checking these inputs
consists of performing a simple continuity/resistance check. Procedures for performing
voltage checks are:
a. Ensure all AISCs have been removed and no power is applied to the Genesis unit.
b. Set a digital ohmmeter to indicate Ohms. Set the ohmmeter range to the resistance
value shown in Table 4-3.
c. Connect the ohmmeter across the analogue input terminals.
d. Ensure the measured resistance is within the expected range. If it is not, check the
analogue input wiring for faults/errors
e. Repeat Steps b. through d. for the remaining inputs associated with AISC Models
TH1 through TH9.
4-1.2.5. Checking Analogue Output Wiring. Analogue output wiring is checked
for the following reasons:
To ensure the analogue output terminals are free of any external voltage
To check continuity through the external analogue circuit
To ensure the resistance of the external analogue circuit is sufficient to avoid
overloading the analogue output circuit.
The following procedures apply to analogue outputs of the Genesis II Digital Controller,
Genesis I Digital Controller, GENII MPC Mid Points Controller and the GENII AO REM
Analogue Output Module. Refer to Section 3 for analogue output terminal numbers for the
applicable Genesis units:
a. Ensure the operating power to the unit is off.
b. Turn on the excitation and operating power for the digital inputs, digital outputs and, as
applicable, the analogue inputs. The reason for this step is to detect the presence of
voltages at the analogue output terminals that may be caused by “sneak” circuits or
wiring errors.
c. At the analogue output terminal, disconnect the active signal wire for the first analogue
output.
d. Connect a digital voltmeter between the disconnected signal wire and the common
terminal.
e. The voltmeter should indicate Zero Volts. Set the voltmeter range as low as possible to
ensure there is no voltage present.
f. Set the voltmeter to the Ohms range. The Ohmmeter should indicate a minimum
resistance of 2,000 or 5,000 Ohms (See Note below). A reading of Infinity Ohms
indicates an open circuit condition that should be corrected.