Overview
The Dwyer A3006 photohelic pressure switch gage is a 3-in-1 instrument that combines precise pressure measurement with reliable switching control. The Dwyer A3000 Series employs time-proven Magnehelic gage design technology, allowing this model to measure and control positive, negative, or differential pressures of air and compatible gases. The gage remains fully functional independent of power supply, providing continuous analog indication even during electrical interruptions.
Key Features
- Dual Function Design: Integrated pressure gage with two DPDT relays for simultaneous measurement and control
- High Repeatability: ±1% of full scale dead band provides chatter-free operation and quick response to pressure changes
- Wide Pressure Capability: Measures positive, negative, or differential pressures; standard models rated to 25 psig with 35 psig and 80 psig options available
- Accuracy & Reliability: ±2% of full scale accuracy at 70°F with time-proven electromechanical relay technology
- Low/High Limit Control: Two form C relays support both low-latching and high-latching circuit configurations
- Field-Adjustable Set Points: Easy-to-adjust knobs accessible on gage face for simple commissioning in the field
Technical Specifications
- Pressure Range: 0–6.0 inches water column (IN WC)
- Maximum Pressure Rating: 25 psig (1.72 bar)
- Accuracy: ±2% of full scale at 70°F (21.1°C)
- Repeatability: ±1% of full scale
- Switch Type: Two form C DPDT relays, rated to 10 amps @ 28 VDC or 120/240 VAC
- Operating Temperature: 20–120°F (−6.67 to 48.9°C); low-temperature option available
- Dial Face Size: 4-inch (101.6 mm)
- Overall Dimensions: 5 inches O.D. × 8.25 inches depth
- Weight: 4 lbs (1.81 kg)
- Process Connection: 1/8″ female NPT
- Service Medium: Air and non-combustible, non-corrosive compatible gases
Typical Applications
- HVAC systems—filter and duct pressure monitoring
- Compressed air system control and diagnostics
- Process differential pressure measurement in clean rooms and laboratories
- Fan and blower discharge pressure switching
- Air handling unit (AHU) controls and safety interlocks
- General industrial pressure indication and alarm functions
Compatibility & Replacements
Compatible With
- Standard 120/240 VAC electrical panel wiring and control circuits
- 28 VDC direct relay drive systems
- Air and non-combustible gases (nitrogen, argon, helium compatible)
- HVAC control systems (standalone or integrated)
- Building automation and industrial process control loops
Replaces / Drop-In Replacement For
- Earlier Series A3000 models with identical 0–6.0 IN WC range
- Other 4-inch face pressure switch/gages requiring dual relay control and independent gage function
- Verify exact model compatibility with application requirements before ordering
Works With
- DPDT relay circuits (both high-latching and low-latching configurations)
- Weatherproof (NEMA 4) enclosure upgrades
- Explosion-proof (NEMA 7 & 9) enclosure options
- Remote-Mounted Relay (RMR) kits for remote installation
- Optional tamper-proof knobs and special scale configurations
