TC3-401T Celsius and Fahrenheit Setup Guide

The TC3-401T is a panel-mounted temperature and time controller for heat press, sublimation and hot-stamping machines. It displays the process temperature in either Celsius (℃) or Fahrenheit (℉), and the display unit is selected through the controller's parameter menu. This guide shows the confirmed keystroke sequence to switch the unit on the TC3-401T, the checks to run immediately afterwards, and the most common setup problems.

Watch how to switch the TC3-401T display between Celsius and Fahrenheit.

Before you start

• Confirm the controller is a TC3-401T (or a TC3-501T / TC3-701T in the same series). The menu codes below are documented for the TC3 series; a different controller may use different parameter names.
• The TC3 series uses a K-type thermocouple input and the published temperature range is 0–400℃. Make sure the sensor is connected and the display shows a believable temperature before you change settings.
• Use the [SET/TEMP] key to enter the parameter menu and the Up/Down arrows to move between parameters and adjust values. Have the controller powered and showing a normal measurement before you begin.
• Switch the unit during commissioning or a planned stop, not while a heating cycle is running, so you can verify the new reading against the process.

Step-by-step Celsius/Fahrenheit setup

The unit is set through the CF parameter, which is hidden behind the LCK lock code. Follow the order below exactly.

1. Enter the parameter menu. Press and hold the [SET/TEMP] button for about 3 seconds until a parameter code appears on the display.
2. Unlock the parameters (LCK). Scroll to the LCK parameter. Use the Up/Down arrows to change its value to 190. The LCK code protects critical parameters from accidental change.
3. Open the unit setting (CF). With the lock released, scroll through the menu until the CF parameter appears.
   • CF = 0 — Celsius (℃)
   • CF = 1 — Fahrenheit (℉)
4. Set the value. Use the Up/Down arrows to set CF to 0 for Celsius or 1 for Fahrenheit.
5. Confirm and exit. Press and hold the [SET/TEMP] button to save. The display returns to the measurement screen with the new unit applied.

Checks after changing the unit

After switching between ℃ and ℉, the displayed measurement unit changes. Whether the existing numeric setpoint, alarm and timing values are automatically converted to the new unit is not confirmed in the published TC3 documentation, so treat every temperature value as needing a manual re-check.

• Verify the live reading. Compare the displayed temperature with the known process or ambient temperature in the new unit. For example, 25℃ should read close to 77℉; if the number is implausible, stop and recheck the CF setting and the thermocouple connection.
• Re-check the setpoint (SV). Open the setpoint and confirm the value is still correct for the new unit. If the displayed value does not match the intended process temperature, re-enter it manually in the new unit — do not assume an automatic conversion.
• Re-check any alarm values. If alarm thresholds are configured, open them and confirm each value in the new unit. Re-enter any value that is not correct.
• Re-check temperature-related parameters. Review any other temperature-linked settings the controller exposes and confirm each one reads correctly in the new unit before returning the machine to service.
• Re-lock the parameters. Return LCK to its locked value so the unit and other settings cannot be changed accidentally during normal operation.

Common problems

The CF parameter does not appear

LCK is still locked. Re-enter the parameter menu, set LCK to 190, then scroll again until CF appears.

The display shows an implausible number after switching

Confirm the K-type thermocouple is connected to the correct terminals with the correct polarity, and that CF is set to 0 (Celsius) or 1 (Fahrenheit) as intended. A reading that is far outside the 0–400℃ range suggests the sensor or setting is wrong rather than a unit problem.

The setpoint looks wrong after the switch

The published TC3 documentation does not confirm automatic conversion of setpoint and alarm values when the unit changes. Re-open each value and re-enter it in the new unit until it matches the intended process temperature.

Settings change on their own during production

LCK is not locked. Return to the parameter menu and restore LCK to its locked value so the unit and other parameters cannot be edited by mistake.

Frequently asked questions

Does the TC3-401T support both Celsius and Fahrenheit?

Yes. The published specification lists the temperature unit as “℃ / ℉ optional”, and the CF parameter selects which unit is displayed.

What is the LCK 190 code for?

LCK is a lock parameter. Setting it to 190 releases the protected parameters, including CF, so they can be edited. Re-lock it after setup to prevent accidental changes.

Are setpoint and alarm values converted automatically when I switch units?

This is not confirmed in the published TC3 documentation. Re-check and, where necessary, re-enter the setpoint, alarm and any other temperature-linked values in the new unit.

What sensor and range does the TC3-401T use?

The published specification identifies a K-type thermocouple input with a 0–400℃ temperature range.

Related product and support

Full specifications, available models and ordering data for the controller are on the TC3-401T product page. More temperature and time controllers are listed under Temperature Controllers.

For help confirming a TC3-401T setting or matching a controller to your heat press application, contact Strong Electric.