Dwyer Instruments DFS2-DM20 Temp Switch
The Dwyer Instruments DFS2-DM20 is a high-performance low limit freeze protection switch engineered to protect cooling coils and heat exchangers in commercial air handling systems. Featuring a 20-foot copper capillary sensing element, this manual reset temperature switch monitors for the lowest temperature detected along any one-foot section of the bulb. Once the temperature drops below the user-defined safety setpoint—adjustable down to 34°F (1°C)—the DPDT relay triggers a signal to the building management system (BMS) and cuts power to the fan to prevent frost damage. Built for durability, the Series DFS2 utilizes a vapor-filled capillary and a rugged galvanized steel base with an ABS cover, carrying a NEMA 1 (IP40) enclosure rating. The 1.8°F fixed deadband and 15A electrical rating make the DFS2-DM20 a reliable choice for HVAC freeze protection in demanding industrial environments. Contractors can easily calibrate the unit via the visual setpoint indicator and screwdriver adjustment slot.
Key Benefits- Comprehensive Monitoring: The 20-foot vapor-filled copper capillary detects the lowest temperature at any point along its length for superior frost prevention.
- BMS Integration: DPDT relay output allows for simultaneous fan shutdown and remote alarm signaling to building automation systems.
- Fail-Safe Design: Manual reset action ensures a technician inspects the system before restarting after a low-temperature trip.
- Precision Adjustment: Includes a visible setpoint scale and a set point safety-lock to prevent unauthorized tampering or accidental changes.
- Robust Construction: Designed with a joint spring protector at the capillary-bellows connection to reduce stress and prevent leaks.
What is the difference between manual and automatic reset on the DFS2 series?
The DFS2-DM20 is a manual reset model, meaning the switch will remain tripped until a technician manually clears the alarm. This is a critical safety feature in HVAC systems to ensure the cause of the freeze condition is identified before the unit resumes operation.
Can this temperature switch be used in outdoor air handlers?
While the DFS2-DM20 is capable of monitoring temperatures down to 34°F, the enclosure is rated NEMA 1 (IP40). It should be installed within a protected control cabinet or a weather-tight enclosure if used in outdoor or wash-down environments.
How do I install the capillary for maximum accuracy?
For effective freeze protection, the capillary should be interlaced across the downstream side of the coil. It is recommended to use capillary mounting clips (Model A-DFS2-C) to ensure the element does not vibrate against the coil fins or frame.
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: $405.18
-65%$405.18
$141.81Dwyer Instruments DFS2-DM20 Temp Switch
The Dwyer Instruments DFS2-DM20 is a high-performance low limit freeze protection switch engineered to protect cooling coils and heat exchangers in commercial air handling systems. Featuring a 20-foot copper capillary sensing element, this manual reset temperature switch monitors for the lowest temperature detected along any one-foot section of the bulb. Once the temperature drops below the user-defined safety setpoint—adjustable down to 34°F (1°C)—the DPDT relay triggers a signal to the building management system (BMS) and cuts power to the fan to prevent frost damage. Built for durability, the Series DFS2 utilizes a vapor-filled capillary and a rugged galvanized steel base with an ABS cover, carrying a NEMA 1 (IP40) enclosure rating. The 1.8°F fixed deadband and 15A electrical rating make the DFS2-DM20 a reliable choice for HVAC freeze protection in demanding industrial environments. Contractors can easily calibrate the unit via the visual setpoint indicator and screwdriver adjustment slot.
Key Benefits- Comprehensive Monitoring: The 20-foot vapor-filled copper capillary detects the lowest temperature at any point along its length for superior frost prevention.
- BMS Integration: DPDT relay output allows for simultaneous fan shutdown and remote alarm signaling to building automation systems.
- Fail-Safe Design: Manual reset action ensures a technician inspects the system before restarting after a low-temperature trip.
- Precision Adjustment: Includes a visible setpoint scale and a set point safety-lock to prevent unauthorized tampering or accidental changes.
- Robust Construction: Designed with a joint spring protector at the capillary-bellows connection to reduce stress and prevent leaks.
What is the difference between manual and automatic reset on the DFS2 series?
The DFS2-DM20 is a manual reset model, meaning the switch will remain tripped until a technician manually clears the alarm. This is a critical safety feature in HVAC systems to ensure the cause of the freeze condition is identified before the unit resumes operation.
Can this temperature switch be used in outdoor air handlers?
While the DFS2-DM20 is capable of monitoring temperatures down to 34°F, the enclosure is rated NEMA 1 (IP40). It should be installed within a protected control cabinet or a weather-tight enclosure if used in outdoor or wash-down environments.
How do I install the capillary for maximum accuracy?
For effective freeze protection, the capillary should be interlaced across the downstream side of the coil. It is recommended to use capillary mounting clips (Model A-DFS2-C) to ensure the element does not vibrate against the coil fins or frame.
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 DFS2-DM20 is a high-performance low limit freeze protection switch engineered to protect cooling coils and heat exchangers in commercial air handling systems. Featuring a 20-foot copper capillary sensing element, this manual reset temperature switch monitors for the lowest temperature detected along any one-foot section of the bulb. Once the temperature drops below the user-defined safety setpoint—adjustable down to 34°F (1°C)—the DPDT relay triggers a signal to the building management system (BMS) and cuts power to the fan to prevent frost damage. Built for durability, the Series DFS2 utilizes a vapor-filled capillary and a rugged galvanized steel base with an ABS cover, carrying a NEMA 1 (IP40) enclosure rating. The 1.8°F fixed deadband and 15A electrical rating make the DFS2-DM20 a reliable choice for HVAC freeze protection in demanding industrial environments. Contractors can easily calibrate the unit via the visual setpoint indicator and screwdriver adjustment slot.
Key Benefits- Comprehensive Monitoring: The 20-foot vapor-filled copper capillary detects the lowest temperature at any point along its length for superior frost prevention.
- BMS Integration: DPDT relay output allows for simultaneous fan shutdown and remote alarm signaling to building automation systems.
- Fail-Safe Design: Manual reset action ensures a technician inspects the system before restarting after a low-temperature trip.
- Precision Adjustment: Includes a visible setpoint scale and a set point safety-lock to prevent unauthorized tampering or accidental changes.
- Robust Construction: Designed with a joint spring protector at the capillary-bellows connection to reduce stress and prevent leaks.
What is the difference between manual and automatic reset on the DFS2 series?
The DFS2-DM20 is a manual reset model, meaning the switch will remain tripped until a technician manually clears the alarm. This is a critical safety feature in HVAC systems to ensure the cause of the freeze condition is identified before the unit resumes operation.
Can this temperature switch be used in outdoor air handlers?
While the DFS2-DM20 is capable of monitoring temperatures down to 34°F, the enclosure is rated NEMA 1 (IP40). It should be installed within a protected control cabinet or a weather-tight enclosure if used in outdoor or wash-down environments.
How do I install the capillary for maximum accuracy?
For effective freeze protection, the capillary should be interlaced across the downstream side of the coil. It is recommended to use capillary mounting clips (Model A-DFS2-C) to ensure the element does not vibrate against the coil fins or frame.
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.
