Dimensions; Coil Sensor Location - RefPlus Guardian+ Quick Start Manual

Dimensions

Remote (Basic) Display
Steps to Ensure Proper Coil Sensor Location
IMPORTANT
Installing the Sensor - The most active portion of the sensor is the first 1/2" of the
probe.
The inset photo in Figure 2 shows that the sensor is positioned so that
it is touching two circuit tubes. When inserting the sensor into the coil,
the tip should touch one of the circuit tubes, and the probe should be in-
serted into the fins approximately 1/16" deeper than the stainless shield-
ing. Pinch the fins gently together, securing the sensor in place. This
provides thermal ballast to ensure a complete defrost.
NOTE: The sensor should not be located adjacent to the electric heating
elements. It should be about half the distance between the heaters if possible.
Alternate Method - As the defrost termination sensor, it is important to ensure the
sensor does not terminate defrost before all frost is removed from the coil. In some
installations, inserting the sensor into the coil may position it too close to the de-
frost heat source. An alternate method of positioning, Figure 3a, places the sensor
vertically between the coil fins. Figure 3b shows the coil sensor properly secured.
NOTE: On a small fraction of installations the sensor placement may require
adjusting. This is typically caused by product loading, door openings, air
flow, etc. The sensor(s) should be placed where the frost disappears last on
the coil.
Extending sensor wires
After the sensors are mounted, they are routed back to the controller. If the wires must
be extended,use 18 gauge twisted shielded pair. Maximum, combined length, for
extension: 100 ft. Contact RefPlus Therm if planning to extend sensor wires beyond
100 ft.
If additional resistance affects the temperature or pressure reading of the con-
troller, the temperature and pressure may be "offset" to read correctly. Use the
OFFSET* function, in the SETPOINTS menu.
When running the sensor wires to the controller avoid introducing electrical noise.
Electrical noise can occur when sensor wires are located near high voltage lines.
Underwriter's Laboratories defines high voltage as above 30V. The higher the
voltage, the more likely electrical noise will occur.
If crossing a high voltage line is necessary, run sensor wiring at right angles to
prevent noise.
* Not available on Basic (Remote) Display.
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