Fourtech Temperature Controller Manual -
Most FourTech controllers have 1 or 2 alarm relays.
| Symptom | Likely Fix |
|---------|-------------|
| Display shows --- or Err | Bad sensor connection or shorted probe |
| Output relay clicks but no power | Load >10A; use external relay/contactor |
| Temperature overshoots | Increase differential (CD/HD) or move probe closer to load |
| Unit resets randomly | Undersized power supply or noise from compressor relay | fourtech temperature controller manual
When using Google, do not just type "fourtech temperature controller manual". Instead, use specific strings: Most FourTech controllers have 1 or 2 alarm relays
| Code | Name | Function | Typical Settings |
| :--- | :--- | :--- | :--- |
| AL1 | Alarm 1 | Sets the temperature for Alarm 1 (High/Low). | e.g., 100°C |
| AL2 | Alarm 2 | Sets the temperature for Alarm 2. | e.g., 110°C |
| Hy | Hysteresis | Dead band for alarm or on/off control. | 1-3 degrees |
| P | Proportional Band | PID Parameter. Low P = Aggressive heating. | Default usually 10-30. |
| I | Integral Time | PID Parameter. | Default usually 100-200. |
| D | Derivative Time | PID Parameter. | Default usually 20-50. |
| InPt / Sn | Sensor Input | Selects sensor type (K, J, Pt100). | K type is standard for most ovens. |
| OutP | Output Type | Defines output signal (Relay, SSR, 4-20mA). | SSr or rEL. |
| LoC | Lock | Locks the keypad to prevent changes. | 0 (Unlock), 1 (Lock Setpoint), 2 (Lock All). | Save and exit
FourTech manuals are available in PDF format. You can find them via: