The T8490 Digital Room Thermostat with Humidity Control is a multifunctional device that offers a simple user interface with push buttons. This stand-alone digital room thermostat is designed to monitor or program temperature control using the onboard or accessory remote temperature sensors. An integral humidity sensor also enables the device to control humidification, dehumidification, and reheating in addition to room temperature. The thermostat’s simple, the at-a-glance screen allows the user to easily see the room temperature and heating or cooling status. The T8490 offers up to four heating and two cooling stages for gas, electric, heat pump, and radiant heat. It is programmable for each day (7-Day), for weekdays plus Saturday and Sunday (5/1/1), or for the same schedule every day (1-Day). For simplicity, it can also operate with no programmed schedule. The thermostat’s programmable auxiliary output allows the user to configure the output to be controlled from a variety of sources. The T8490 is compatible with outdoor sensors, displaying current, high, and low temperatures for the day. The user has the option to display temperatures in either degrees Fahrenheit or degrees Celsius. Setup step instructions on the scrolling display can be set for English, French, or Spanish. The keypad lockout capability enforces setpoint energy policies by preventing tampering with the digital room thermostat settings in public spaces. The thermostat features a dual-setpoint setting and setpoint limiting. An optional plug-in Skyport™ Wi-Fi module is available as an accessory for the T8490. This module allows the user to monitor and control the thermostat remotely with a mobile device app. Refer to the T8490 Commercial Digital Thermostat with Humidity Control Owner’s Manual and Installation Instructions (LIT-12012478) for important commercial product application information.
Repair Information
If the T8490 Series Digital Room Thermostat with Humidity Control fails to operate within its specifications, replace the unit. For a replacement thermostat, contact the nearest Johnson Controls® representative.
Product Code Number | Description |
T8490 | Digital Room Thermostat with Humidity Control |
ACC-E-WIFI | Wi-Fi Module for the T8490 Digital Room Thermostat |
ACC-E-WALLPLT | Plastic Backplate for Surface Mounting the T8490 Digital Room Thermostat |
ACC-RSEN | Remote Temperature Sensor |
ACC-RSEN-OVR | Remote Temperature Sensor with Manual Override |
T8490 Digital Room Thermostat with Humidity Control Catalog Page (Continued)
T8490 Digital Room Thermostat with Humidity Control | ||
Power Requirements | 20 to 30 VAC, 50/60 Hz, 3.0 VA at 24 V nominal | |
Output Rating | W1, W2, W3 = 0.2 A maximum, 0.01 A minimum, 3 A inrush, 20 to 30 VAC; Y1, Y2, G = 0.4 A maximum, 0.01 A minimum, 3 A inrush, 20 to 30 VAC; HUM, DEHUM, AUX = 0.1 A maximum, 0.01 A minimum, 3 A inrush, 20 to 30 VAC | |
Local Temperature Sensor Type | Thermistor, NTC 10K at 77°F (25°C) | |
Remote Temperature Sensor Type | Thermistor, NTC 10K at 77°F (25°C) | |
Wire Size | 16 AWG (100 ft [30.5 m] maximum) to 24 AWG (36 ft [11 m] maximum) | |
Temperature Adjustment Range | 35 to 99°F (2 to 37°C) | |
Accuracy | 35 to 65°F ±3F° (2 to 18°C ±1.8C°), greater than 65 to less than 80°F ±2F° (18 to less than 27°C ±1.2C°); 80 to 99°F ±3F° (27 to 37°C ±1.8C°), greater than 99 to 104°F ±5F° (37 to 40°C ±3C°) | |
Humidity Control | ±10% RH from 30 to 70% RH, 50 to 90°F (10 to 32°C) | |
Deadband | Adjustable 1 to 6 degrees first stage; Adjustable 0 to 10 degrees second and third stages | |
Ambient Conditions | Operating | 35 to 104°F (2 to 40°C), 5 to 95% RH noncondensing, 86°F (30°C) maximum dew point |
Storage | -22 to 122°F (-30 to 50°C), 5 to 95% RH noncondensing, 86°F (30°C) maximum dew point | |
Compliance | UL/cUL listed, file E107041, NEC Class 2 | |
Dimensions | 4.4 in. H x 5.2 in. W x 1.0 D (112 mm H x 132 mm W x 25 mm D) | |
Shipping Weight | 0.75 lb (0.34 kg) |
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The performance specifications are nominal and conform to acceptable industry standards. For applications at conditions beyond these specifications, consult the local Johnson Controls office. Johnson Controls shall not be liable for damages resulting from the misapplication or misuse of its products. © 2018 Johnson Controls. www.johnsoncontrols.com
DOWNLOAD MANUALS:
Johnson Controls T8490 Digital Room Thermostat PRODUCT SPECIFICATION GUIDE
Johnson Controls T8490 Digital Room Thermostat PRODUCT SPECIFICATION GUIDE
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