Algas SDI VAPORAIRE M-Series, Operation & Maintenance Manual

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Operation
SDI Operations & Maintenance Manual – 54264
4-25
PLC CONTROLLER LED INDICATORS AND MODE SWITCH
There are LED’s on the PLC for diagnostic and status that indicate the operation
of the control system and each venturi solenoid valve. The LED indicators can
also show potential problems with the system to help troubleshoot faults.
Under normal conditions the POWER and RUN LED’s should always be on.
See the Troubleshooting Section if both LED’s are not on or if the FAULT
LED is on.
SEQUENCER
, modules and LED’s are described in Section 1 .
When the system is operating normally the following sequencer LED’s will be lit:
POWER STATUS
RUN STATUS
INPUT STATUS will only be on if the input is active
OUTPUT STATUS will only be on if the output is active
The mode switch must always be in the up -
RUN
- position.
ANALOG INPUT MODULE(S)
The analog input module receives a 4 - 20mA signal from the Mixed Gas
pressure transmitter and uses this signal to control the mixing system. The
transmitter is wired to CI-0 of the analog input module. There are no LED
indicators on the analog input module.
MIXED GAS PRESSURE TRANSMITTER
The Mixed Gas pressure transmitter is a control input to maintain mixed gas
pressure setpoint (Delivery Pressure) and monitor High Mixed Gas Pressure
Safety backup. The High Mixed Gas Pressure Safety backup is a setpoint in the
SEQUENCER
controller that is set 5 PSIG above mixed gas pressure setpoint.