Bulletin 100-50-9.1 –
Page 19
5.4.5.2 WIRING
With controller unpowered, carefully route the pressure
transducer cable to the controller. Take caution to route the
cable away from sharp edges, fans and defrost heaters. Ensure
the terminal screws on the controller are backed all the way
out. Insert the leads of the sensor wire into “Pressure” location
on the controller, see chart below for sequence. Tighten the
terminal screws to 3-5 in.-lb. Carefully tug the leads to ensure
they are secure. See the following figure.
Note: If a Case
Controller and Valve Module are used, the pressure
transducer may be wired into either controller or two
pressure transducers may be used for redundancy.
5.4.6 RH/AMBIENT TEMPERATURE (RHT)
SENSOR
5.4.6.1 MOUNTING
The RHT sensor is required when using pulsed anti-sweat
heater control. The sensor must be mounted within 10 ft. of
the case. Position the sensor outside of the case and away from
periodic air movements such as cooling or heating air vents.
5.4.6.2 WIRING
With controller unpowered, carefully route the RHT cable
to the controller. Take caution to route the cable away from
sharp edges. Ensure the terminal screws on the controller
are backed all the way out. Insert the leads of the sensor
wire into “Humidity” location on the controller, see chart
below for sequence. Tighten the terminal screws to 3-5 in.-
lb. Carefully tug the leads to ensure they are secure. See the
following figure.
5.4.5 SUCTION PRESSURE TRANSDUCER
5.4.5.1 MOUNTING
The suction transducer is required when using an EEV and where superheat calculation is needed. It is also required when
controlling an EEPR off of pressure. The sensor must be mounted on the suction line after the evaporator as shown below.
The piping must be horizontal and free draining. Position the sensor at 12 o’clock on the suction line near the coil outlet
temperature and tighten to 6-8 ft.-lb.
Note: Copper gasket is not recommended between Schrader valve and
transducer. On multi-coil cases, a transducer per evaporator or transducer per case may be used.
Pressure Transducer Cable
Case Control
or Valve Module
Black
5V
White
S
Green
Gnd
Coil Outlet
Sensor
Pressure
Transducer
Defrost
Termination Sensor
EEV
10”-14”
minimize
1”- 2” ideal
Evaporator
Refer to the evaporator manufacturer’s
installation/orientation instructions.
Pressure Range Listed on Label
1/4” SAE Flare Installation
Torque: 6-8 ft.-lb.
RHT Cable
Case Control
Red
5V
Yellow
CL
Black
Gnd
