WarmlyYours PD Pro Snow Switch User Manual
Page 16
Snow Switch
®
Model PD Pro
Instruction Manual
23735
Rev. B
06/14 (800) 234-4239
http: www.networketi.com
Environmental Technology, Inc.
16 of 30
CIT–1 AND GIT–1 SENSOR TESTING
The CIT–1 and GIT–1 sensors have two interrelated systems: the temperature sensing system
and the moisture detection system. Complete testing of the sensor involves manipulation of
both. The tools needed for this procedure are a voltmeter and an aerosol circuit cooler (“Freeze
Spray” is preferred) or cup of ice water. The Freeze Spray is available at most electric supply
stores.
Ensure that the moisture sensing grid on the sensor is clean and dry.
Follow the steps below to perform the CIT–1 and GIT–1 sensor post-installation test procedure.
The SIT–6E testing procedure is on the next page.
1.
Connect the voltmeter across the black and red leads from the sensor (low-voltage
wiring terminals at the control). Connect the black test lead to the black wire. You
should obtain a reading of 23 to 28 VDC. Now, check the reading across the black and
white sensor leads. You should read 22 to 28 VDC with a warm (above 38°F) and dry
sensor. Both the SNOW LED and HEAT LED should remain off.
2.
Cool the temperature probe of the sensor with the Freeze Spray. You should see frost
form on the temperature probe. Alternately, place the temperature probe in ice water.
The SNOW LED and HEAT LED should remain off.
3.
Using a moist finger, touch the moisture sensing grid on top of the sensor. Both the
SNOW LED and HEAT LED should come on and the voltage between the white and black
sensor leads should be less than 2 VDC.
4.
With the unit cold and the sensing grid moist, allow the unit to warm up to above 38°F.
The SNOW LED should turn off and the HEAT LED should stay on and the voltage should
return to 22 – 28 VDC. Record results on page 2 of this manual.
5.
If testing a SIT–6E sensor, proceed to the next section now. If testing is complete, with
unit powered off, restore all wiring connections and re- install the face plate and clear
plastic cover. Set the Hold-On Time control dial to the desired setting.