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Electrical Ratings
Model Adjustable Switch Resistive (Non-Inductive)
Number Operating Range Action 120 VAC 240 VAC 277 VAC 125-277 VAC
770-1 0.05 to 12.0 W.C. SPDT 15.0A 15.0A 15.0A 300 VA
770-3 0.05 to 12.0 W.C. SPDT 15.0A 15.0A 15.0A 300 VA
770 SERIES DUAL PURPOSE AIR SWITCH
Responds to Positive, Negative or Differential Air Pressure
FEATURES
• Design eliminates “fluttering” or malfunction due to shock or vibration normally
encountered with “sail switches”.
• Wide operating range.
• Furnished with one 12” piece 1 /4” O.D. flexible tubing, nuts and ferrules.
• Can be mounted in any position except upside down.
• Enclosed diaphragm.
SPECIFICATIONS
Ambient Temperature . . . . . . . . -40 to +180°F
Maximum Pressure . . . . . . . . . 1/ 2 PSI
Agency . . . . . . . . . . . . . . . . . . . . . . . . . . . U.L. listed and C.S.A. approved
1/ 2 HP @ 125 VAC
770-1
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AIR SWITCH APPLICATIONS
ELECTRONIC AIR CLEANERS
Switch permits power to cleaner whenever
blower of system is operating.
PROCESS DRYING
Switch monitors negative pressure to stop
conveyor or process and provides alarm
signal on fan failure. Ideal for bulk
chemicals, food processing, grain drying.
POWER HUMIDIFIERS
Switch permits unit to operate whenever
there is proper air movement.
NATURAL DRAFT BURNERS
Switch signals insufficient draft, provides
safety limit to stop firing on lack of draft,
starts again on sufficient draft.
REFRIGERATION EQUIPMENT
Switch responds to pressure drop across
refrigeration coils to signal alarm condition
or automatically initiate or terminate
defrost cycle.
INDUCED DRAFT BURNERS
Proves operation of I.D. fan by sampling
draft or air flow. Shuts off firing equipment
on fan failure.
DUCT STRIP HEATERS
Switch proves air movement across
heaters by positive pressure to prevent
burn-out on insufficient air flow.
DUAL PURPOSE
AIR SWITCH
Indicates Canadian Model Number: call 1-800-305-6953 to order 
76
HEATING