Overview & Function

• Model: KH4000A

• Application: Specialized computer control board and display interface designed for industrial dryers and commercial laundry equipment.

• Dimensions: 120 mm × 120 mm (Front Panel)

• Core Functions: Controls drying cycles, monitors real-time temperatures via NTC thermistors, manages heating/cooling/fan relays, and displays operational status via an LCD.

2. Component breakdown

A. Front Display Panel (Left)

• LCD Screen: Displays operational status, targeted temperature, runtime, and diagnostic error codes.

• Control Buttons:

  • Enter ($\boldsymbol{\hookleftarrow}$): Confirm / Select setting.

  • Up ($\boldsymbol{\uparrow}$) & Down ($\boldsymbol{\downarrow}$): Parameter adjustment / Navigation.

  • Computer/Menu Icon: System configuration / Diagnostics mode.

  • Power Button ($\boldsymbol{\text{Power}}$): Turn unit on/off.

  • Heating Icon ($\boldsymbol{\approx}$): Manual heating control toggle.

  • Cooling Icon ($\boldsymbol{\snowflake}$): Manual cooling / air-dry cycle toggle.

  • Play/Start Icon ($\boldsymbol{\blacktriangleright}$): Start drying program.

B. Main Control Board / PCB (Right)

• Relay Modules: 5 onboard blue relays to switch heavy loads (e.g., heating elements, fan motors, drum rotation forward/reverse, steam valves).

• Fuses: Dual protection glass fuses (FP1 and FP2) on both sides of the relay block for overcurrent safety.

• Microcontroller Unit (MCU): Features an integrated processor running firmware build V100B1 (Board Marking: C.X.LL004A.CPU-360).

• Input/Output Terminals:

  • NTC1 / NTC2: Temperature sensor probe inputs.

  • COM1 / COM2 / JP1 / JP2: Main power inputs and relay load output connectors.

  • RJ1 Port: Communication link port to connect the main circuit board to the front keypad/display unit.

3. General Specifications