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 fixed 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. • Vapor-filled 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 FEATURES/BENEFITS SPECIFICATIONS Sensing ElementVapor-filled capillary. Operating Temperature14°F to 54°F (-10°C to 12°C). Storage Temperature14°F to 158°F (-10°C to 70°C). Capillary Overload Temperature392°F (200°C), maximum 60 min. Humidity Limit0 to 95% RH, non-condensing. EnclosureGalvanized steel base, ABS cover. Enclosure RatingNEMA 1 (IP40). Capillary MaterialCopper. Cable Entry(1) M20 compression fitting. Reset ActionAvailable in automatic or manual reset options. Low-level SetpointFactory Set: 39°F (4°C), and safety lock secured; Adjustment via screwdriver slot. Wire ConnectionTerminal with wire-retaining screws. Wire SizeMax. 14 AWG. Electrical Rating24-250 VAC, 15 (8) A. Electrical ConnectionsTwo each NO/NC/Common. Deadband1.8°F (fixed). Weight1.6 lb (0.7 kg). Agency ApprovalsCE. DESCRIPTIONAPPLICATIONS SERIES DFS2 | LOW LIMIT FREEZE PROTECTION SWITCH ® Manual reset option shownDIMENSIONSWIRING DIAGRAM SERIES DFS2: Low limit freeze protection switch RESET ACTION -DM: Manual -DA: Automatic CAPILLARY LENGTH 10: 10´ (305 cm) 20: 20´ (609 cm) DFS2-DM20 HOW TO ORDER Use the bold characters from the chart below to construct a product code. ACCESSORIES ModelDescription A-DFS2-CCapillary mounting clips (6 pieces) ©Copyright 2019 Dwyer Instruments, Inc. Printed in U.S.A. 10/19 DS-DSF2 Rev. 1 ORDER ONLINE TODAY! dwyer-inst.com/Product/SeriesDFS2 DWYER INSTRUMENTS, INC. Important Notice: Dwyer Instruments, Inc. reserves the right to make changes to or discontinue any product or service identified 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. 4-9/64 [110.67] 13/32 [10.32] 2-7/8 [73.03] 33/64 [13.10] 19/32 [15.03] 19/32 [15.03] 1-31/32 [50] 3-17/64 [82.95] MOUNTING HOLE 1-5/32 [29.37] 13/64 [5.16] MOUNTING HOLE M20 Ø3/32 [Ø2.38] CAPILLARY 3/32 [2.38] 29/32 [23.02] Ø1-37/64 [Ø40.08] 2-3/32 [53.18] 7/16 [11.11] MANUAL RESET UNITS ONLY WHITE BLUE RED WHITE BLUE RED NC NO COMMON NC NO COMMON LEFT RIGHTNext >