WD_2021
71R SERIES
PRESSURE SWITCHES
RED DOT TRINARY ™ PRESSURE SWITCHES - GENERATION II
This switch assembly performs three distinct func- tions. The first function prevents the compressor from operating if system charge is lost or ambient temperature is too low. The second stops compres- sor if head pressure increases to unsafe levels. It automatically resets when pressure drops back to normal. The third function is a shutter/fan override switch that keeps head pressure within normal range by opening shutters or operating engine fan to increase air flow across condenser when head pressure rises above set valve. Install Trinary on liquid side of a/c system between condenser and expansion valve. For use with R-12 and R-134a systems.
OPENS
CLOSES
Low Pressure Protection
22.5 ± 7.5 PSIG
40 Psig Maximum ( Rising Pressure ) 230 ± 20 PSIG 200 - 230 PSIG ( Rising Pressure )
( Descending Pressure )
High Pressure Protection Shutter Fan/Override
325 ± 25 PSIG 35 - 60 PSIG
Below Closing Pressure
RD-5-4585-0P MOUNTING CONFIGURATION 71R7600
71R7500
RD-5-4620-0P
3 ⁄ 8 ” - 24 UNF-2A Male thread with bulkhead seal, 2-012 O-Ring Shutter/fan switch is normally open
3 ⁄ 8 ” - 24 UNF-2A Male thread with bulkhead seal, 2-012 O-Ring Shutter/fan switch is normally closed
SWITCHES
ELECTRICAL 7 AMP Resistive 4 AMP Inductive 28 VOLT D.C. Maximum 2.50 Series Male Tab Terminals TRINARY ™ E/C Connection end of TRINARY TM
71R7550
71R7650
RD-5-4583-0P
RD-5-4625-0P
7 ⁄ 16 ” - 20 UNF-2B Female thread for male Schrader Shutter/fan switch is normally open
7 ⁄ 16 ” - 20 UNF-2B Female thread for male Schrader Shutter/fan switch is normally closed
4
3 1 2
RED DOT TRINARY TM HARNESS
Terminals 1 & 2 Controls Clutch High/LowPressure Protection Terminal 1: To compressor clutch “compressor” black wire Terminal 2: To thermostat “AC/Thermostat” black/white wire Terminals 3 & 4 Controls Fan Clutch or Shutters Terminal 3: To solenoid valve “override” yellow wire Terminal 4: To ignition “DC power” orange wire
71R4501 RD-5-12150-0P TRINARY TM boot ( provides a molded 4 wire connection to Trinary switch; lead wires are 28” long. ) helps eliminate terminal corrosion and breakage.
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