Model Series: 91-Series Control Boards

Technical Specifications:

• Board Dimensions: 145 mm × 95 mm × 1.6 mm (approx.)
• Layer Count: 4-layer FR-4
• Microcontroller: 8-bit MCU (OTP ROM type)
• Operating Voltage: 5V DC (regulated on-board) / 230V AC input stage
• Input Channels: 4 analog inputs (0–10V / 4–20mA)
• Output Channels: 6 relay outputs (250V AC / 5A) + 2 triac outputs
• Communication Interface: RS-485 (Modbus RTU compatible)
• Operating Temperature: -20°C to +85°C
• Conformal Coating: Acrylic conformal coat applied
• Connector Type: Phoenix Contact plug-in terminals (5.08 mm pitch)
• Component Standard: RoHS compliant, lead-free solder (SAC305)

Functional Features:

• On-board AC-DC power supply (230V AC to 5V DC / 3.3V DC)
• Watchdog timer for system fault recovery
• EEPROM storage for parameter retention during power loss
• EMC filtering on all I/O lines (common-mode chokes + TVS diodes)

Material Composition:

• Substrate: FR-4 epoxy glass (TG170)
• Copper Trace Thickness: 35 µm (1 oz) outer layers, 17.5 µm inner layers
• Solder Mask: Green LPI (Liquid Photoimageable)
• Surface Finish: HASL (Hot Air Solder Leveling) — lead-free

Working Principle:
The 230V AC input is rectified and regulated to 5V DC by the on-board SMPS stage. The 8-bit microcontroller executes the control algorithm, reading analog sensor inputs via an ADC (10-bit resolution), and driving relay/triac outputs through optocoupler isolation. The RS-485 interface enables remote monitoring and parameter adjustment.

Advantages & Highlights:

• Fully potted power section for vibration and moisture resistance
• Modular connector system — field-replaceable without soldering
• Wide operating temperature range for boiler room environments
• Built-in surge protection on all external connections

Applicable Industries:

• Gas boiler control systems
• Washing machine electronic controllers
• HVAC system controllers
• Industrial process controllers

Installation Requirements:

• Install in enclosed control cabinet with IP54 minimum rating
• Maintain minimum 20 mm clearance around board for heat dissipation
• Use shielded cable for RS-485 communication (max 1200 m length)
• Ground the chassis to protective earth (PE)

Usage Precautions:

• Do not apply voltage to board without verifying all connector pin assignments
• Replace only with exact part number 91-00911-05 — firmware is board-specific
• Store in anti-static bag at 10–30°C, <60% RH before installation
• Do not expose to condensing environments without conformal coating verification