STC-9200 Thermostat

The STC-9200 digital temperature controller manages three loads: the refrigeration device, the defrosting unit, and the Evaporator Fan. It is typically suited for oversized freezer rooms.

1. Wiring Diagram

The wiring diagram illustrates the terminal connections for the STC-9200. It features power input terminals (Live, Neutral/Null, Earth, Power Supply Input), output terminals (1-6) for Compressor, Defrosting, and Fan. Sensor input terminals include Room Sensor (7), Co-point of Sensors (8), and Defrosting Sensor (9). A 'Copy Key' is also indicated.

2. Set the Target Temperature

To maintain the room temperature within a specified range, typically from 'F1' (SET) to 'F1 + F2' (SET + HY). Settings can be adjusted via the user interface or the Admin Interface. The following describes the Admin Interface method.

Step 1: Enter Admin Interface

Hold the [SET] key and the [▼] key simultaneously for 10 seconds. The display will show 'F1' (SET).

Step 2: Adjust Value

Press the [SET] key to view the current value. Use the [↑] or [↓] keys to change the value for 'F1'.

Step 3: Save and Return

Press the [SET] key to save the new data. The unit will return to the menu list, displaying 'F1' (SET) again.

Step 4: Navigate to Next Parameter

Switch to the 'F2' (HY) code by pressing the [↑] key.

Repeat steps 2-4 to update other parameters as needed. The unit will automatically exit the setting mode and return to normal status after 10 seconds of inactivity.

Parameter Definitions:

• F1 (SET): SP (Temperature Set-Point)
• F2 (HY): Temperature Hysteresis / Return Difference
• F3 (US): Upper limit for SP
• F4 (LS): Lower limit for SP
• F5 (AC): Delay Time for the Compressor and delay time for defrosting if it was Hot Gas mode (F10 = 1 (TDF = HTG)).

If the 'F1' (SET) value cannot be modified as required, adjust 'F3' (US) and 'F4' (LS) as they define the limitations for 'F1' (SET).

3. Configure the Defrosting

This unit controls defrosting based on Time and Temperature.

Temperature Condition:

Defrosting is initiated if the evaporation sensor temperature is lower than the preset 'defrosting Stop temperature', F8 (DTE). This is a critical value to prevent over-defrosting.

Time Condition 1:

Defrosting occurs when the real-time passes the preset interval time, F6 (IDF), a standard parameter for most defrosting thermostats.

Time Condition 2:

If the defrosting method is set to 'Hot Gas' (F10 = 1 (TDF = HTG)), the unit counts the compressor's last stop moment plus F5 (ac). This acts as a protective measure against frequent compressor startups and stops.

Defrosting Parameters:

• F6 (IDF): Defrosting Cycle / Interval Time
• F7 (ADF): Defrosting Lasting/Running Time
• F8 (DTE): Defrosting Stop Temperature
• F9 (FDT): Defrosting Water Dripping Time
• F10 (TDF): Defrosting Mode:
  • 0 (EL): Electric-Heating
  • 1 (HTG): Hot Gas from the compressor
• F11 (DCT): Count mode of defrost cycle:
  • 0 (RT): Cumulative time from controller power on
  • 1 (COH): Cumulative time of the compressor working
• F12 (DFD): Display mode when defrosting:
  • A. 0 (RT): Shows the room sensor temperature display.
  • B. 1 (IT): Shows the evaporator sensor temperature. This display continues for 10 minutes after defrosting is over.

4. Set the Evaporation Fan

Check the F15 (FOD) value before configuring other fan settings.

Evaporation Fan Control Logic:

The control logic for the evaporation fan is determined by the F15 (FOD) parameter:

• If F15 (FOD) is less than 0: The fan starts earlier than the refrigeration cycle. Parameters F13, F14, and F16 are not used in this mode.
• If F15 (FOD) is greater than 0: The fan is controlled by F13 (FNC).

F13 (FNC) Fan Output Modes:

When F15 (FOD) is greater than or equal to 0, F13 determines the fan's operation:

• A. 0 (CTR): Fan starts by F14 (FOT) and stops by F16 (FST).
• B. 1 (O-N): Continuous working, except during defrosting periods.
• C. 2 (C-N): In this mode, F15 (FOD) specifies the delay time for the fan to start after the compressor. The fan stops if defrosting begins.

Fan Control Parameters:

• F15 (FOD): Time delay in seconds for the Fan.
• F14 (FOT): Defrost sensor temperature for Fan Starts.
• F16 (FST): Defrost sensor temperature for Fan Stops.

5. Set the Alarm

The alarm function is based on the room sensor temperature. It also triggers if the evaporator sensor is broken.

Alarm Parameters:

• F17 (ALU): Upper Temperature of the Room sensor to Trigger Alarm.
• F18 (ALL): Lower Temperature of the Room sensor to Trigger Alarm.
• F19 (ALD): Time delay of the Room sensor to Trigger Alarm.
• F20 (OT): Temperature Calibration = Real Temperature - Measured Temperature.

This document is a quick start guide and highlights key points. For comprehensive instructions, refer to the Full-Content Version User Manual.

Brand: Haswill Electronics

Product: STC-9200 Defrost Fan Controller

Copyright Haswill-Haswell All Rights Reserved

For more information, visit www.thermo-hygro.com.