Overview
The Dwyer 3015 Series A3000 Photohelic® Switch/Gauge combines versatile pressure control with precision analog measurement. This switch/gauge functions as a highly repeatable pressure switch combined with a precise pressure gauge employing the time-proven Magnehelic® gauge design, and measures and controls positive, negative or differential pressures of air and compatible gases. With optical limit switches and solid-state technology, it delivers reliable performance in HVAC systems, process control, and industrial automation applications without degradation during high-cycle operation.
Key Features
- Two phototransistor actuated, DPDT relays for low/high limit control
- Individual set point deadband of one pointer width (less than 1% of full scale), with interlocking capability for variable deadband ideal for fan and damper control
- Gauge reading is continuous and unaffected by switch operation, even during loss of electrical power
- Temperature range of 20–120°F with ±2% accuracy at 70°F
- Optical limit switches individually aligned for precise switching accuracy
- Clear polycarbonate cover with external knob adjustment for easy set point configuration
Technical Specifications
- Pressure range: 0–15 inches of water column (w.c.)
- Standard rating to 25 psig (1.7 bar)
- Operating temperature: 20–120°F (−6.67–48.9°C)
- Accuracy: ±2% of full scale at 70°F
- Relay type: 2 Form C relays for each set point
- Power supply: 120 VAC, 50–60 Hz (240 and 24 VAC optional)
- Connection: 1/8″ NPT female inlet, 1″ conduit opening
- Media: Clean dry air and non-combustible, non-corrosive gases
- Switch technology: Optical limit switch with infrared LED and phototransistor
- Includes screw terminals for electrical connections
Typical Applications
- HVAC system pressure monitoring and control (supply/return dampers, fan interlocks)
- Clean room and laboratory pressure differential control
- Compressed air system monitoring
- Process equipment pressure limits and safety interlocks
- Ductwork pressure management and balancing
- Filter clogging detection and maintenance alerts
Compatibility & Replacements
Compatible With
- HVAC control systems and BMS integration (24–120 VAC)
- Pneumatic damper and valve actuators
- PLC and automation control panels
- Direct pressure measurement applications (no transmitter required)
- Standard electrical enclosure and panel mounting
Replaces / Drop-In Replacement For
- Dwyer A3015 (equivalent base model)
- Dwyer 3015C (standard 120 VAC version)
- Legacy Magnehelic® switches requiring combined pressure display and control
Works With
- DPDT relay switching for logic-based control circuits
- 24 VAC or 120 VAC facility power (optional configurations available)
- Standard NPT thread fittings and ductwork connections
- Pneumatic and HVAC control system protocols
- Manual pressure adjustment without software or programming
