Dwyer Instruments 1638-2 Pressure Switch

The Dwyer Instruments 1638-2 Pressure Switch is a high-precision, large-diaphragm instrument engineered for monitoring differential pressure in air conditioning and industrial process applications. This SPDT differential pressure switch features a robust 1.0" w.c. to 3.0" w.c. operating range, providing essential reliability for damper positioning and duct air control. Designed for use with air and non-combustible gases, the unit utilizes a 1/8" female NPT process connection and is housed in a durable casing suitable for vertical mounting. Technicians benefit from the visible set point indicator and external screw adjustment, which simplify field calibration and troubleshooting. With an electrical rating of 15A at 120-480 VAC, this industrial pressure switch manages small electrical loads or motor starters without requiring additional relays. The large diaphragm design ensures a tight repetitive accuracy of ±1%, maintaining a narrow 0.06-0.08" w.c. deadband for precise system cycling and enhanced HVACR equipment performance.

• Enhanced Accuracy: The large diaphragm design provides superior low-range sensitivity and repetitive accuracy within ±1%.
• Simplified Setup: Integrated visible set point indicator allows for rapid adjustments and clear status verification in the field.
• Versatile Electrical Duty: High-capacity 15-amp SPDT switch supports a broad range of HVAC and process applications.
• Rugged Reliability: UL and CSA listed, and FM approved for general industrial service, ensuring long-term stability in demanding environments.
• Technical Standard: Standard 1/8" female NPT connections ensure compatibility with existing pneumatic lines and test manifolds.

What is the maximum pressure limit for the Dwyer 1638-2?
This series is rated for a continuous pressure limit of 10 psig (68.95 kPa) and can withstand surges up to 25 psig (172.4 kPa).

Can this switch be mounted in any orientation?
For maximum accuracy and to maintain the calibrated set point, the unit must be mounted with the diaphragm in a vertical position.

Is the 1638-2 compatible with liquid media?
No, this model is specifically designed for air and non-combustible gases. Using it with liquids may damage the internal diaphragm or compromise the switch action.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.