
IceFree3_Turbine_Control_Vane_Manua
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| Rev 3.0 | 30 January 2015 | [email protected] || 7
General Sensor Information
Heater Operation
The heat source for the IceFree3 is a self-regulating constant-temperature heater. In severe wind and icing
conditions, the IceFree3 draws full power and remains clear of ice. As weather conditions improve, the IceFree3
draws less power. The IceFree3’s self-regulating feature increases its reliability, insuring that the head does not
reach excessive temperatures. The IceFree3 heater is powered by 24 volt power, AC or DC, making it compatible
with a wide range of remote site equipment. An optional 120/240V - 24 VAC transformer is also available.
Following a brief inrush current, the heater quickly settles into its temperature-controlled mode.
It is recommended that a 15 A slow-blow fuse be placed in line with the heater.
Installation
1. Tape the ends of the cables to prepare them for feeding through the mounting boom. Maintain the isolation of
the signal leads from the boom. Remove the nut and bolt from the base of the unit. Feed the cables through the
mounting boom until the sensor is on the boom. Align the bolt hole in the base (not the slot) with the hole in the
boom such that the hole in the base points forward toward the rotor blades.
2. Check to be sure that the sensor is secure against the top of the boom. Insert the bolt into the slot side of the
base. Place the nut on the end of the bolt and tighten.
3. Using the notations on the individual wires, connect the ground (common) lead to your controller first. Then
connect the signal leads. Connect power last, especially if power is on during connection. Confirm input on
controller.
4. Connect the heater power cable to your power source and check to be sure that the sensor head is heating.
You do not need to wait until the body gets hot to be sure the heaters are working. Any warmth at the top of the
stem (near the head) means that the heaters are working. The lower housing will take longer to warm up and
will not get as hot.
IceFree sensors should be heated year-round to maintain constant bearing temperatures and to prevent
moisture or condensation internally. We do not recommend turning off the heaters, even in warm
weather.
*Calibration
If the IceFree sensor has been calibrated, a sensor specific calibration report has been shipped with the sensor.
If the calibration report should get lost, you may contact NRG for a copy. Please note that you will need the
sensor serial number when you contact NRG.
ESD, Circuit Protection, and Cautions
Do not apply greater than 30 Volts to the outputs at any time.
We suggest that you not mount the sensor until the proper grounding is available. When you mount the
sensor, protect the signal wires and connect the ground first. After connecting to ground, attach the
signal wires from the sensor.
There are internal TVS diodes on the output. If the output voltage is pulled above 30 V, or below ground,
the diode will clamp the output to ground.
Do not apply constant reverse voltages to the outputs. The internal diode is intended only to protect the
sensor output from transient reverse voltages, for example, the inductive turn-off spike caused by driving
reed-relay coils directly from the output.