Overview
The Dwyer 3150C Photohelic pressure switch gauge is a combined pressure measurement and control instrument designed for industrial HVAC, clean room, and pneumatic applications. This Series 3000 Photohelic® switch/gage functions as a versatile, highly repeatable pressure switch combined with a precise pressure gage and measures and controls positive, negative or differential pressures of air and compatible gases. Gage reading is continuous and unaffected by switch operation, even during loss of electrical power.
Key Features
- Two phototransistor-actuated DPDT relays included for low/high limit control with easy-to-adjust set point indicators controlled by knobs on the gage face
- Individual set point deadband less than 1% of full scale, ensuring chatter-free operation
- 1% full scale dead band provides quick response to pressure changes with no delay in switching
- Available in full scale pressure ranges from 0-.25″ w.c. up to 30 psi
- Clear polycarbonate front cover for easy visibility of setpoint knobs and zero adjustment
- Screw terminal connections using 167°F (75°C) copper conductors
Technical Specifications
- Standard pressure range: -20″ Hg to 25 psig with MP option to 35 psig and HP option to 80 psig
- Accuracy: ±2% of full scale at 70°F
- Relay type: 2 Form C relays (DPDT) per setpoint
- Relay capacity: 10 A @ 28 VDC, 10 A @ 120/240 VAC
- Sensing media: Clean dry air and non-combustible compatible gases
- Connection: Screw terminals
- Certifications: CE, CSA, UL
Typical Applications
- HVAC systems and room pressure monitoring
- Pneumatic conveying systems
- Clean room differential pressure control
- Fume exhaust system monitoring
- Fan and damper control circuits
- Alarm and signal applications with latching capability
Compatibility & Replacements
Compatible With
- 120 VAC and 240 VAC electrical control systems (standard)
- 24 VAC relay pack option available
- Low/high latching and combination latching circuits
- Magnetic contactor and motor starter circuits
- Building automation and pneumatic control systems
Replaces / Drop-In Replacement For
- Earlier Dwyer Series 3000 Photohelic models with compatible pressure ranges
- Verify part number compatibility with your system integrator before ordering
Works With
- Dwyer A-601 manual reset push buttons
- Standard 120 VAC/240 VAC control relays and contactors
- 24 VAC relay packs (special order)
- HVAC building management systems requiring dry contact switching
