Chamber Heater Troubleshooting

Your chamber heater is pre-configured and should arrive ready to go. If this is not the case, then use the following troubleshooting guide to recover operation.

Chamber Heater Indicator Says "Off" in Octoprint CI Edition

Locate the temperature controller pictured above with green numeric output. The controller, manufactured by OMEGA, is located on a steel DIN rail underneath the electronics shell of the printer.

There are 4 buttons underneath the display of the controller. From left to right, when looking at screen so it is right-side-up and buttons are underneath screen (note: controller is mounted sideways), they are:

  • UP button - this moves up a level in the menu structure.
  • LEFT button - this cycles left through the level you are currently on
  • RIGHT button - cycles right through the level
  • ENTER - either selects an option or goes down one level in menu structure, like entering a folder on a PC.

Communications Configuration

If the chamber heater says "off" then there is an error in communication between the temperature controller and the primary onboard computer module. Use the instructions below to ensure that the communications configuration on the temperature controller is correct.

Configure Communication Protocol

  1. Locate the temperature controller.
  2. Select INIT from top level menu and press ENTER
  3. Thumb over to CoMM and press ENTER
  4. Thumb over to USB and press ENTER
  5. Select PROT for “Protocol” and press ENTER
  6. Select “M.bUS” for MODBUS Protocol and press ENTER
  7. Select “RtU” and press ENTER
  8. Navigate back up to top menu.
  9. Power cycle printer and verify chamber heater reading in Octoprint.
  10. Communications should now be correctly configured.

Set Controller to Run Mode

Ensure the temperature controller is in Run mode. On the temperature controller click the following:

  1. Press the UP button as many times as needed until you reach the top level menu. The screen will display either "PRoG" for Programming, "INIt" for Initialization, or "oPER" for Operation.
  2. once you are at the top level, hit LEFT or RIGHT until the display reads "oPER". Then press ENTER to enter the Operation folder.
  3. Now the screen should display "RUN". Go left/right to find "RUN" if it does not. Press ENTER to activate run mode and the screen should now display the process value (current temperature being measured)
  4. If something other than temperature is being displayed when you press RUN then the thermocouple sensor has most likely been disconnected or broken.

Verify Wiring

If the communications configuration is verified as above, but Octoprint still says Off in the output reading for Chamber, then you may have a loose or disconnected wire. Follow the wiring verification procedure below if this is the case.

USB Connector

  1. Verify USB cable is functional by plugging into a different micro-USB device.
  2. Try different USB connector on printer onboard computer.

Re-seat USB connectors and power cycle. USB connector is shown below running between the onboard computer (top black box) and the temperature controller (bottom digital readout display).

Input Wiring

There are 2 removable screw terminal blocks at the back of the controller, one for inputs with pins 1-10, and one for outputs/power with pins 1-8.

INPUT connections are as follows:

  • Thermocouple blue wire goes to INPUT 2
  • Thermocouple red wire goes to INPUT 3

Ensure that wire leads do not cross as this will cause faulty measurement

Output Wiring

OUTPUT connections are as follows:

  • Power in goes to pins 7/8
  • OUTPUT 3 goes to HEATER relay (-), relays should be labeled, if not the heater relay is the one of the two large narrow Crydom relays that has a tan wire hooked to its output.
  • OUTPUT 4 goes to HEATER relay (+)
  • OUTPUT 5 goes to FAN relay (-)
  • OUTPUT 6 goes to FAN relay (+)

Configure Temperature Controller for Type T Thermocouple Input

If the controller is not reading a proper output for temperature, the thermocouple type may not be configured correctly. Follow the instructions below on the temperature controller to ensure that the controller is configured for the Type T thermocouple input. It is uncommon to need to perform this step.

  1. Press UP button (to left) several times until you are at top level (will say either OPER, PROG, or INIT)
  2. Press LEFT/RIGHT buttons to thumb over to INIT
  3. Press ENTER (to right) to select INIT menu
  4. Navigate to INPT with LEFT/RIGHT and press ENTER
  5. Navigate to t.C. for “thermocouple” and press ENTER
  6. Navigate to t for “Type T Thermocouple” and press ENTER
  7. Controller is now properly configured for Type T thermocouple input
  8. Verify thermocouple is reading room temperature properly

Programming DC1/DC2

DC1 and DC2 must be programmed properly for proper operation of outputs. Follow the instructions below to program correctly. It is uncommon to need to perform this step.

  1. Go to top level - PROG and press ENTER
  2. Go to DC1 and press enter
  3. Select MODE - enter, “PID” and press enter
  4. “ACTN” will appear for “Action” - press ENTER, select RVRS for reverse, press ENTER
  5. Thumb over to CYCL for cycle time in HZ, input 000.1 and press ENTER
  6. Go back to PROG - ENTER
  7. Thumb over to PID to select parameters for PID that DC1 was previously assigned to this PID, press ENTER
  8. ACTN - enter - RV.dR - enter - back up to ACTN
  9. Over to %Lo (low state % output) - ENTER - input 70 - ENTER
  10. Over to %Hi (hi state % output) - ENTER - input 100 - ENTER
  11. All other settings factory default should be fine, DC1 fan output should now be correctly configured. Proper operation to check for is that fan turns on to 70% when setpoint is higher than measured value, turns on to 100% when setpoint is below measured value (to cool faster, fan should never turn off when controller is in RUN mode)
  12. Go to PROG - DC2 and press enter
  13. Select MODE - enter, go over to ON.OF for on/off or “bang-bang” control of heater
  14. Back up to MODE, over to CYCL for cycle time in Hz, input 000.1 and press ENTER
  15. DC2 heater output should now be correctly configured. Proper operation is ON (relay light illuminated) when trying to heat, OFF when it is above setpoint

Chamber Heater Provides Reading But Does Not Heat

If the issue is that the screen displays temperature but that temp does not rise as commanded, please ensure that the steps in the steps in this troubleshooting guide have been followed with particular attention to any loose wires. If all of the items above have been covered, then check the thermal circuit breaker fuse as described below.

Thermal Circuit Breaker

If the thermal circuit breaker has gone above 180°C, the thermal breaker will trip and cut power to the heater and blower. If this is the case, the thermal breaker needs to be reset. Power off your printer at the orange switch on the back of the printer then press the red button on the heater shown below. The button should click if the breaker has tripped.