Dwyer 3002MR Photohelic Pressure Switch 25 Psi

Product Description

The DWYER 3002MR is a Photohelic pressure switch designed for differential pressure measurement and switching in HVAC, ventilation, and industrial process applications. Rated to a maximum of 25 psi with 2% accuracy, it combines analog pressure indication with integrated switching capability in a single instrument. The 1/8 inch NPT threaded connection allows straightforward installation into existing process lines. Calibrated for 2 inches water column range, the unit is suitable for monitoring filter status, fan performance, and duct pressure in both commercial and light industrial environments. Licensed HVAC technicians and instrumentation technicians are the primary installers.

The 3002MR fits residential and commercial HVAC systems where a combined pressure gauge and switch function is required in a compact format. Typical applications include air handler filter monitoring, cleanroom differential pressure control, duct static pressure sensing, and fan proving. The 1/8 inch NPT port accommodates standard instrument tubing fittings common in HVAC and process control installations.

Key Features

• Maximum pressure rating of 25 psi for a wide range of HVAC and process applications
• 2% accuracy provides reliable differential pressure readings for critical switching functions
• Integrated photohelic design combines analog gauge indication with electrical switching in one unit
• 1/8 inch NPT threaded connection for compatibility with standard instrument fittings
• 2 inch water column range suited to low-differential-pressure sensing applications
• Maximum operating temperature of 120 degrees F appropriate for typical mechanical room environments

Compatibility

Designed as an OEM-style replacement or direct-install Photohelic pressure switch for residential and commercial HVAC differential pressure monitoring systems requiring a 1/8 inch NPT connection and 25 psi maximum rating.

Installation Notes

Installation should be performed by a licensed HVAC technician or instrumentation professional familiar with low-voltage control wiring and pressure instrument commissioning. Shut off system power and isolate the process line before connecting or disconnecting the pressure ports. Follow all applicable NEC requirements when wiring the switch contacts. Do not exceed the 25 psi or 120 degrees F maximum ratings during operation or pressure testing.