Installation Operation Maintenance

MaintenanceTo Test Humidity SensorsReturn Air Humidity Sensor ECA RAH/RAEOutdoor Humidity Sensor ECA OAH/OAETo test this circuit, place a DC milliamp meter in series with either of the leads to the humidity sensor. If the readingis 0ma, polarity may be reversed. Reverse + & - and retest. If the reading does not correspond to the table below,check the output voltage from the ECA with the sensor disconnected. It should be approximately 20VDC. If so, andall connections are intact, replace the sensor. If 20VDC is not present, yet the ECA green LED is on, the ECA modulehas failed.Humidity sensor accuracy : +/-10% RH.Table 56 - Humidity sensor testRH% DCma RH%D Cma RH% DCma100% 20.000 52.6 12.414 31.2 9.00097.7 19.636 51.7 12.273 30.8 8.92695.5 19.286 50.8 12.135 30.3 8.85293.4 18.947 50.0 12.000 29.9 8.78091.4 18.621 49.2 11.868 29.4 8.71089.4 18.305 48.4 11.739 29.0 8.64087.5 18.000 47.6 11.613 28.6 8.57185.7 17.705 46.8 11.489 28.1 8.50483.9 17.419 46.1 11.368 27.7 8.43882.1 17.143 45.3 11.250 27.3 8.37280.5 16.875 44.6 11.134 26.9 8.30878.8 16.615 43.9 11.020 26.5 8.24477.3 16.364 43.2 10.909 26.1 8.18275.7 16.119 42.5 10.800 25.8 8.12074.3 15.882 41.8 10.693 25.4 8.06072.8 15.652 41.2 10.588 25.0 8.00071.4 15.429 40.5 10.485 24.6 7.94170.1 15.211 39.9 10.385 24.3 7.83368.8 15.000 39.3 10.286 23.9 7.82667.5 14.795 38.7 10.189 23.6 7.77066.2 14.595 38.1 10.093 23.2 7.71465.0 14.400 37.5 10.000 22.9 7.66063.8 14.211 36.9 9.908 22.5 7.60662.7 14.026 36.4 9.818 22.2 7.55261.5 13.846 35.8 9.730 21.9 7.50060.4 13.671 35.3 9.463 21.6 7.44859.4 13.500 34.7 9.558 21.2 7.39758.3 13.333 34.2 9.474 20.9 7.34757.3 13.171 33.7 9.391 20.6 7.29756.3 13.012 33.2 9.310 20.3 7.24855.4 12.857 32.7 9.231 20.0 7.20054.4 12.706 32.2 9.15353.5 12.558 31.7 9.07666RT-SVX20B-E4