Following are the LEDs and indicators we can use in the enclosure to try and troubleshoot status of hardware.
Confirm which mode the unit is in: Multi Zone, Single Zone, or Off/Config.
This gives some information on the visual indicators we can use for troubleshooting (see also photo attachment):
HMI/CPU is the PLC and Display unit that runs the program
-It has a number of clearly marked LED’s on the back of it
PWR – Power
RUN – System is in RUN Mode (The system should always be in RUN)
-There is a mechanical switch on the back of display for RUN/STOP – Keep on RUN
STOP – This LED should not be on EVER, if it is then toggle the switch from STOP to RUN. STOP is only used for programming
ERR – Error LED should not be illuminated, if it is re-boot the system and see if ERR clears. ERR should only come on if the system is in a fail mode and with the application we shouldn’t see this unless wires have been moved by the user
X00-X07 – These are 24V DC Inputs. The only X LED that will illuminate is the X00. The Snow Sensor trigger is connected to X00. If the Snow Sensor is ON the X00 will be illuminated, when it goes off the system will go into AFTER RUN stage
- Snow Owl has a self-test mode when powered up. If you turn power on to the system, the X00 will momentarily respond ON-OFF-ON-OFF-ON-OFF. This tells you the sensor is connected and working.
- If the X00 is one for 5 MIN, the system will assume Snow and start running
Y00-Y17 – These are Relay Outputs. If Y10 is illuminated that means ZONE 1 is running, Y11 is illuminated that means ZONE 2 is running, Y12 is illuminated that means ZONE 3 is running, Y13 is illuminated that means ZONE 4 is running,
ANALOG Card – Is attached to the back for the HMI and should have a GREEN LED indicating power and connectivity to the HMI
Power Supply has a GREEN LED indicating it has POWER
-If the LED is not illuminated, check to make sure you have 110VAC on the Power Supply terminals
-If you have 110V on the terminals, you should have 24VDC on the OUTPUT terminals
-If you are not seeing 24VDC on the OUTPUTS – FIRST check wire connections and screw terminals
-If everything is connected correctly and secure – Replace Power Supply
-If the LED is illuminated – Power Supply should be working correctly
This device is powered off 24VDC, is taking in a 10K OHM signal from the slab sensor and converting it to 0-10VDC which is what the HMI/CPU requires for an Analog Input
Signal Conditioner has a AMBER LED indicating it has POWER
-If the LED is not illuminated check terminals 1 & 2 for 24VDC
-If power is present on 1 & 2, check the reading on terminals 5 & 6 (the attached chart should correspond VOLTAGE to TEMP)
-Based on the Voltage, the HMI should have a reading in line with the above linear chart
-If no Voltage is present, check wire connections and screw terminals
Relays are labeled ZONE 1, ZONE 2, ZONE 3 & ZONE 4 with a printed tag. Each Relay has a GREEN LED that will come on indicating the ZONE is ON.
-ZONE 1 Relay LED Should be on when that ZONE is running and HMI/CPU LED Y10 should be on as well
-ZONE 2 Relay LED Should be on when that ZONE is running and HMI/CPU LED Y11 should be on as well
-ZONE 3 Relay LED Should be on when that ZONE is running and HMI/CPU LED Y12 should be on as well
-ZONE 4 Relay LED Should be on when that ZONE is running and HMI/CPU LED Y13 should be on as well