Description
The Dwyer 1900-5-MR is a precision engineered compact low differential pressure switch from Dwyer’s Series 1900, designed for reliable pressure control and safety monitoring in HVAC, refrigeration, air handling, and industrial systems. With a manual reset feature, this switch ensures that pressure conditions must be acknowledged before resetting, making it ideal for critical or alarm-driven applications where automatic resetting isn’t desired.
Key Features
- Differential pressure range: 1.4 to 5.5 inches water column (W.C.), suitable for low-pressure differential monitoring and control tasks.
- Manual reset option (MR): Requires physical reset after activation, helping prevent unintended switch cycling in safety-critical systems.
- SPDT switch contact: Provides a single-pole double-throw output for flexible control or alarm circuits.
- 1/8″ NPT female pressure ports: Standard process connections for easy integration with pressure lines.
- Internal setpoint adjustment: Screw adjustment located inside the enclosure gives simple and secure setpoint configuration while minimizing tampering risks.
- Compact, rugged design: Zinc-plated steel housing and silicone diaphragm provide durability in typical HVAC and compatible gas environments.






