Overview
The Dwyer 1823-0 differential pressure switch is a compact, low-cost monitoring device from the 1800 Series designed for industrial HVAC, filtration, and process control applications. It delivers 0.15–0.5″ W.C. pressure range with ±2% repeatability, making it suitable for applications where high precision is not required but reliability and affordability are essential. The unit is rated for 15 A @ 120–480 VAC and operates reliably across a wide temperature range.
Key Features
- Compact, space-efficient design — small footprint for panel and wall mounting in tight industrial spaces
- Set point adjustment accessible from mounting stud — install switch on one side of panel, adjust from opposite side
- SPDT contact configuration — single-pole double-throw switching for flexible control logic
- 2% repeatability — accurate enough for general industrial service, HVAC filters, and low-pressure monitoring
- Rugged construction and regulatory approvals — UL, CSA, FM, and CE listed for industrial reliability
Technical Specifications
- Pressure Range: 0.15–0.5″ W.C. (water column)
- Switch Type: Single-pole double-throw (SPDT)
- Electrical Rating: 15 A @ 120–480 VAC, 60 Hz; 1/8 HP @ 125 VAC, 1/4 HP @ 250 VAC
- Deadband: Approximately 0.06″ W.C. at minimum and maximum set points
- Repeatability: ±2%
- Process Connection: 1/8″ Female NPT
- Operating Temperature: −30 to 180°F (−34 to 82.2°C)
- Maximum Pressure Limit: 10 psig (0.69 bar)
- Media Compatibility: Dry air and non-combustible gases
- Mounting Orientation: Diaphragm in vertical position
- Set Point Adjustment: Screw type inside mounting stud
- Weight: 1 lb 5 oz (595 g)
- Agency Approvals: CE, UL, CSA, FM
Typical Applications
The Dwyer 1823-0 is widely used in:
- HVAC systems — filter clogging detection and ductwork pressure monitoring
- Air compressor discharge monitoring — low-pressure alarm and control
- Pneumatic process lines — pressure detection for blow-off systems and tool operation
- Panel-mounted control cabinets — remote or wall-mounted pressure alarm systems
- Industrial ventilation — confirming airflow and filter status in clean-room and manufacturing environments
Compatibility & Replacements
Compatible With
- Standard industrial control relay circuits and PLC input modules
- 24 VDC and 120 VAC control logic circuits
- HVAC control systems and building management systems (BMS)
- Pneumatic tool control and compressed air systems
- Panel-mounted switching and alarm circuits
Replaces / Drop-In Replacement For
The Dwyer 1823-0 may replace or interchange with other low-pressure switches in the 1800 Series or equivalent Dwyer models in similar pressure ranges. Verify exact compatibility with your control system integrator before ordering, particularly if replacing an existing unit in a live system.
Works With
- Industrial relay and contactor wiring systems
- 24 VDC solenoid valve control circuits
- 120/240 VAC alarm and indicator lamp circuits
- Programmable Logic Controllers (PLCs) via digital input modules
- HVAC thermostats and building automation systems
