Dwyer Instruments 1640-0 Switch
The Dwyer Instruments 1640-0 Switch is a high-precision differential pressure switch engineered for specialized HVACR applications requiring floating contact null switch logic. Unlike standard snap-acting switches, the 1640 series utilizes a single-pole double-throw (SPDT) floating contact design to provide two distinct actuation points—high and low—with a defined "null" zone in between. This makes it an ideal solution for motorized damper control and maintaining static pressure or air velocity in supply ducts. With an adjustable range of .01" w.c. to 0.2" w.c. and a narrow 0.01-0.03 adjustable null span, this unit ensures stable positioning without constant equipment cycling.
Designed for use with air and non-combustible gases, the 1640-0 features a large, sensitive diaphragm that maintains accuracy even at extremely low pressures. The visual setpoint adjustment allows for straightforward field calibration, while the 1/8" female NPT connections and 10 psig pressure limit ensure compatibility with standard pneumatic and sensing lines. For contractors managing variable air volume (VAV) systems or constant volume supply ducts, this switch provides the reliable, non-inductive switching needed to drive repositioning motors effectively.
Key Benefits for Technicians- Precise Null Zone Control: Adjustable 0.01-0.03 null span prevents motor hunting by maintaining a deadband between high/low points.
- Durable Diaphragm Construction: Large diaphragm area provides maximum sensitivity for low-range duct static pressure monitoring.
- Simplified Troubleshooting: Features a clear, calibrated scale for visual setpoint adjustment without needing external manometers for basic configuration.
- HVAC System Versatility: Dual-point actuation is perfect for damper positioning and air velocity control via pitot tube sensing.
- Reliable Integration: Standard 1/8" NPT connections and SPDT floating contacts allow for seamless replacement in existing control loops.
How do I wire the Dwyer 1640-0 for damper motors?
The SPDT floating contact design typically requires a relay or a motor controller capable of handling low-current signals. The "high" contact closes on rising pressure to rotate the motor in one direction, while the "low" contact closes on falling pressure for the opposite rotation. When in the null zone, the motor remains at rest.
Can this switch be used with combustible gases?
No. The 1640-0 is strictly rated for air and non-combustible gases. Using this with flammable media can lead to hazardous conditions and equipment failure.
What is the maximum surge pressure for the 1640-0?
While the continuous operational limit is 10 psig, the unit is designed to withstand surge pressures up to 25 psig without damaging the internal diaphragm.
This item is not eligible for free shipping.
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.
Original: $844.59
-65%$844.59
$295.61Dwyer Instruments 1640-0 Switch
The Dwyer Instruments 1640-0 Switch is a high-precision differential pressure switch engineered for specialized HVACR applications requiring floating contact null switch logic. Unlike standard snap-acting switches, the 1640 series utilizes a single-pole double-throw (SPDT) floating contact design to provide two distinct actuation points—high and low—with a defined "null" zone in between. This makes it an ideal solution for motorized damper control and maintaining static pressure or air velocity in supply ducts. With an adjustable range of .01" w.c. to 0.2" w.c. and a narrow 0.01-0.03 adjustable null span, this unit ensures stable positioning without constant equipment cycling.
Designed for use with air and non-combustible gases, the 1640-0 features a large, sensitive diaphragm that maintains accuracy even at extremely low pressures. The visual setpoint adjustment allows for straightforward field calibration, while the 1/8" female NPT connections and 10 psig pressure limit ensure compatibility with standard pneumatic and sensing lines. For contractors managing variable air volume (VAV) systems or constant volume supply ducts, this switch provides the reliable, non-inductive switching needed to drive repositioning motors effectively.
Key Benefits for Technicians- Precise Null Zone Control: Adjustable 0.01-0.03 null span prevents motor hunting by maintaining a deadband between high/low points.
- Durable Diaphragm Construction: Large diaphragm area provides maximum sensitivity for low-range duct static pressure monitoring.
- Simplified Troubleshooting: Features a clear, calibrated scale for visual setpoint adjustment without needing external manometers for basic configuration.
- HVAC System Versatility: Dual-point actuation is perfect for damper positioning and air velocity control via pitot tube sensing.
- Reliable Integration: Standard 1/8" NPT connections and SPDT floating contacts allow for seamless replacement in existing control loops.
How do I wire the Dwyer 1640-0 for damper motors?
The SPDT floating contact design typically requires a relay or a motor controller capable of handling low-current signals. The "high" contact closes on rising pressure to rotate the motor in one direction, while the "low" contact closes on falling pressure for the opposite rotation. When in the null zone, the motor remains at rest.
Can this switch be used with combustible gases?
No. The 1640-0 is strictly rated for air and non-combustible gases. Using this with flammable media can lead to hazardous conditions and equipment failure.
What is the maximum surge pressure for the 1640-0?
While the continuous operational limit is 10 psig, the unit is designed to withstand surge pressures up to 25 psig without damaging the internal diaphragm.
This item is not eligible for free shipping.
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.
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Description
The Dwyer Instruments 1640-0 Switch is a high-precision differential pressure switch engineered for specialized HVACR applications requiring floating contact null switch logic. Unlike standard snap-acting switches, the 1640 series utilizes a single-pole double-throw (SPDT) floating contact design to provide two distinct actuation points—high and low—with a defined "null" zone in between. This makes it an ideal solution for motorized damper control and maintaining static pressure or air velocity in supply ducts. With an adjustable range of .01" w.c. to 0.2" w.c. and a narrow 0.01-0.03 adjustable null span, this unit ensures stable positioning without constant equipment cycling.
Designed for use with air and non-combustible gases, the 1640-0 features a large, sensitive diaphragm that maintains accuracy even at extremely low pressures. The visual setpoint adjustment allows for straightforward field calibration, while the 1/8" female NPT connections and 10 psig pressure limit ensure compatibility with standard pneumatic and sensing lines. For contractors managing variable air volume (VAV) systems or constant volume supply ducts, this switch provides the reliable, non-inductive switching needed to drive repositioning motors effectively.
Key Benefits for Technicians- Precise Null Zone Control: Adjustable 0.01-0.03 null span prevents motor hunting by maintaining a deadband between high/low points.
- Durable Diaphragm Construction: Large diaphragm area provides maximum sensitivity for low-range duct static pressure monitoring.
- Simplified Troubleshooting: Features a clear, calibrated scale for visual setpoint adjustment without needing external manometers for basic configuration.
- HVAC System Versatility: Dual-point actuation is perfect for damper positioning and air velocity control via pitot tube sensing.
- Reliable Integration: Standard 1/8" NPT connections and SPDT floating contacts allow for seamless replacement in existing control loops.
How do I wire the Dwyer 1640-0 for damper motors?
The SPDT floating contact design typically requires a relay or a motor controller capable of handling low-current signals. The "high" contact closes on rising pressure to rotate the motor in one direction, while the "low" contact closes on falling pressure for the opposite rotation. When in the null zone, the motor remains at rest.
Can this switch be used with combustible gases?
No. The 1640-0 is strictly rated for air and non-combustible gases. Using this with flammable media can lead to hazardous conditions and equipment failure.
What is the maximum surge pressure for the 1640-0?
While the continuous operational limit is 10 psig, the unit is designed to withstand surge pressures up to 25 psig without damaging the internal diaphragm.
This item is not eligible for free shipping.
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.
