Watts 519 Installation & Operation Manual - page 7
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©203WattsRadiant
Floor Sensor 079 Testing
Agoodqualitytestmetercapableofmeasuringupto5,000kΩ(kΩ=000Ω)is
requiredtomeasurethesensorresistance.Inadditiontothis,theactualtemperature
mustbemeasuredwitheitheragoodqualitydigitalthermometer,orifathermometer
isnotavailable,asecondsensorcanbeplacedalongsidetheonetobetestedand
thereadingscompared.
Firstmeasurethefloortemperatureusingthethermometer.DisconnecttheSand
Comwiresfromthethermostat.Usinganelectricalmeter,measuretheresistance
oftheSandComwiresatthethermostatlocation.Usingthetemperatureversus
resistancetable,estimatethetemperaturemeasuredbythesensor.Thesensor
measurementandthermometerreadingsshouldbeclose.Ifthetestmeterreads
averyhighresistance,theremaybeabrokenwire,apoorwiringconnectionora
defectivesensor.Iftheresistanceisverylow,thewiringmaybeshorted,theremay
bemoistureinthesensororthesensormaybedefective.Totestforadefective
sensor,measuretheresistancedirectlyatthesensorlocation.Oncethetesthas
beencompleted,reconnecttheSandComwirestothethermostat.
Temperature vs. Resistance Table
Temperature
Resistance
°F
°C
-50
-46
490,83
-45
-43
405,70
-40
-40
336,606
-35
-37
280,279
-30
-34
234,96
-25
-32
96,358
-20
-29
65,80
-5
-26
39,402
-0
-23
8,08
-5
-2
00,22
0
-8
85,362
5
-5
72,98
0
-2
62,465
5
-9
53,658
20
-7
46,28
25
-4
39,93
30
-
34,558
Temperature
Resistance
°F
°C
35
2
29,996
40
4
26,099
45
7
22,763
50
0
9,900
55
3
7,436
60
6
5,3
65
8
3,474
70
2
,883
75
24
0,50
80
27
9,299
85
29
8,250
90
32
7,334
95
35
6,532
00
38
5,828
05
4
5,20
0
43
4,665
5
46
4,84
Donotapplyvoltagetoasensoratanytimeasdamagetothesensormayresult.