TEC26x7-2 Series BACnet® MS/TP Networked Thermostats with Two Outputs Installation Instructions
24
Technical Specifications
Thermostat Will
Not Come Online
See the probable causes listed in the
Multiple Symptoms
section earlier in this table.
A thermostat may be connected to the wrong bus.
A baud rate may be specified in the new thermostat that is incompatible with the running network.
No device on the network is configured to use a specific baud rate (normally the NAE), but all devices
are set to use auto baud. At least one device, typically the bus supervisor (NAE), must have an
assigned baud rate. Set the baud rate in the bus supervisor and set all other devices to auto baud.
1.
For common MS/TP troubleshooting information, refer to the
MS/TP Communications Bus Technical Bulletin
(LIT-12011034).
Table 8: Display Messages
Display
Function
Service
Indicates that there is a service alarm in accordance with the programmable Binary Input (BI2).
Filter
Indicates that the filter(s) is dirty in accordance with the programmable Binary Input (BI2).
Window
Indicates that an outside window or door is open and has cancelled the thermostat heating or cooling
action in accordance with the programmable Binary Input (BI1).
Table 7: Troubleshooting Details
1
(Part 2 of 2)
Symptom
Probable Causes
TEC26x7-2 Series BACnet MS/TP Networked Thermostats with Two Outputs (Part 1 of 2)
Power Requirements
19 to 30 VAC, 50/60 Hz, 2 VA (Terminals 4 and 5) at 24 VAC Nominal, Class 2 or
Safety Extra-Low Voltage (SELV)
Relay/Triac
Contact
Rating
On/Off and
Floating
Control
30 VAC, 1.0 A Maximum, 15 mA Minimum, 3.0 A In-Rush, Class 2 or SELV
Analog
Output Rating
Proportional
Control
0 to 10 VDC into 2k ohm Resistance (Minimum)
Auxiliary
Output Rating
Triac Output
30 VAC, 1.0 A Maximum, 3.0 A In-Rush
Digital Inputs
Voltage-Free Contacts across Terminal Scom to Terminals BI1, BI2, or UI3
Temperature Sensor Type
Local 10k ohm Negative Temperature Coefficient (NTC) Thermistor
Wire Size
18 AWG (1.0 mm Diameter) Maximum, 22 AWG (0.6 mm Diameter) Recommended
MS/TP Network Guidelines
32 Devices Maximum; 4,000 ft (1,219 m) Maximum Cable Length
Temperature
Range
Backlit
Display
-40.0°F/-40.0°C to 122.0°F/50.0°C in 0.5° Increments
Heating
Control
40.0°F/4.5°C to 90.0°F/32.0°C
Cooling
Control
54.0°F/12.0°C to 100.0°F/38.0°C
Accuracy
±0.9F°/±0.5C° at 70.0°F/21.0°C Typical Calibrated
Minimum Deadband
2F°/1C° between Heating and Cooling
Ambient
Conditions
Operating
32 to 122°F (0 to 50°C); 95% RH Maximum, Noncondensing
Storage
-22 to 122°F (-30 to 50°C); 95% RH Maximum, Noncondensing