The WHD Series is a smart environmental controller designed to regulate temperature and humidity inside high-voltage switchgear, ring main units, transformer boxes, and other critical enclosures. Available in various form factors and input/output configurations, the WHD controller provides automatic heating and fan control, real-time measurement, and RS485 Modbus communication. It is widely used to prevent failures caused by moisture condensation, overheating, or insulation damage. With robust performance and ease of installation, the WHD Series offers reliable protection and monitoring for industrial electrical systems.

Technical Specifications

Feature	Specification
Model Options	WHD48, WHD72, WHD46, WHD20R
Display Interface	LCD display with temperature and humidity readout
Measurement Range	Temperature: -40.0°C to 99.9°C
Control Channels	1-channel (11), 2-channel (22), 3-channel (33)
Accuracy	Temperature: ±1°C Humidity: ±5% RH
Analog Output (optional)	DC 4–20 mA
Control Outputs	Relay contacts for heating and fan control
Communication Interface	RS485 (Modbus-RTU)
Auxiliary Power Supply	AC 85–265V or DC 100–350V
Power Consumption	≤0.8W basic + ≤0.7W per relay channel
Contact Capacity	5A @ AC 250V
Operating Temperature	-20°C to +60°C
Storage Temperature	-40°C to +85°C
Humidity (Non-Condensing)	≤95% RH
Altitude	≤2500m
Installation	Panel-mount (cut-out specific) or DIN 35mm rail

  Functions

• Real-time temperature and humidity measurement for up to 3 zones
• Relay output for heating or fan control to maintain setpoints
• High/low temperature and humidity alarms
• RS485 Modbus-RTU communication for BMS/EMS integration
• Local setup and programming via LCD and push-button interface
• Optional analog signal transmission (4–20 mA) for integration with analog systems
• Anti-condensation logic for protection against moisture faults

Applications

• High-voltage switchgear compartments
• Ring main units and cable terminal boxes
• Distribution transformer kiosks
• Industrial electrical cabinets and panels
• Smart substation environments
• Tunnel and metro power enclosures

Manufacturer Information

Acrel Co., Ltd., established in 2003, is a high-tech enterprise specializing in energy efficiency management and electrical safety solutions. With a comprehensive product line ranging from cloud platform software to sensors, Acrel offers smart energy meters, power sensors, and protection devices. Their products are widely utilized across industries such as electric power, communications, rail transit, petrochemical, and construction. In 2012, Acrel was listed on the Growth Enterprise Market with the stock code 300286.SZ. The company is committed to delivering innovative and reliable energy management solutions to its global clientele.