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SERIES DFS2 | LOW LIMIT FREEZE PROTECTION SWITCH
®
Manual reset option shown
FEATURES/BENEFITS
• Vapor-lled copper capillary sensing element
• Joint spring protector at capillary-bellow connection
• Set point safety-lock protection and simple adjustment
• Easy installation and wiring
• Automatic and manual reset
• HVAC Equipment
• Heat Exchangers and Cooling coils
SPECIFICATIONS
Sensing Element Vapor-lled capillary.
Operating Temperature 14°F to 54°F (-10°C to 12°C).
Storage Temperature 14°F to 158°F (-10°C to 70°C).
Capillary Overload Temperature 392°F (200°C), maximum 60 min.
Humidity Limit 0 to 95% RH, non-condensing.
Enclosure Galvanized steel base, ABS cover.
Enclosure Rating NEMA 1 (IP40).
Capillary Material Copper.
Cable Entry (1) M20 compression tting.
Reset Action Available in automatic or manual reset options.
Low-level Setpoint Factory Set: 39°F (4°C), and safety lock secured; Adjustment via screwdriver slot.
Wire Connection Terminal with wire-retaining screws.
Wire Size Max. 14 AWG.
Electrical Rating 24-250 VAC, 15 (8) A.
Electrical Connections Two each NO/NC/Common.
Deadband 1.8°F (xed).
Weight 1.6 lb (0.7 kg).
Agency Approvals CE.
DESCRIPTIONAPPLICATIONS
The Series DFS2 Low Limit Freeze Protection Switch protects
cooling coils in air handler systems by preventing frost build up. The
thermostat and its capillary sensing element provide an antifreeze
function by sensing the lowest temperature along any one foot section of
capillary. The DPDT manual or automatic reset relays signal the building
management system as well as cut off the fan. The Series DFS2 will
detect temperature drops below the xed safety value (set point) which
can be set as low as 34°F (1°C) utilizing the visual set point indicator and
set point screw.
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DIMENSIONS WIRING DIAGRAM
COMMON
COMMON
LEFT
RIGHT
7/16 [11.11]
13/32
[10.32]
MOUNTING
HOLE
M20
4-9/64 [110.67]
2-7/8 [73.03]
MOUNTING HOLE
13/64
[5.16]
1-31/32
1-5/32
[29.37]
19/32
[15.03]
Ø3/32
[Ø2.38]
CAPILLARY
[50]
33/64
[13.10]
3-17/64
[82.95]
19/32 [15.03]
3/32
[2.38]
29/32
[23.02]
MANUAL RESET
UNITS ONLY
2-3/32 [53.18]
Ø1-37/64
[Ø40.08]
NC
NO
NC
NO
HOW TO ORDER
Use the bold characters from the chart below to construct a product code.
DFS2 -DM 20
WHITE
BLUE
RED
WHITE
BLUE
RED
SERIES
DFS2: Low limit freeze protection switch
RESET ACTION
-DM: Manual
-DA: Automatic
ACCESSORIES
Model Description
A-DFS2-C Capillary mounting clips (6 pieces)
CAPILLARY LENGTH
10: 10´ (305 cm)
20: 20´ (609 cm)
ORDER ONLINE TODAY!
dwyer-inst.com/Product/SeriesDFS2
DWYER INSTRUMENTS, INC.
©Copyright 2019 Dwyer Instruments, Inc.
Printed in U.S.A. 10/19 DS-DSF2 Rev. 1
Important Notice: Dwyer Instruments, Inc. reserves the right to make changes to or discontinue any product or service identied in this publication without notice. Dwyer advises its customers to obtain the
latest version of the relevant information to verify, before placing any orders, that the information being relied upon is current.
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