Honeywell manual Operation, Output 3 models TB6980B and TB7980B, Minimum and Maximum Setpoints

4.5 Output 3 (models TB6980B and TB7980B)

The following table shows the output types for Output 3 and their corresponding settings in the configuration menu.

Menu setting		Description
0	Not used
1	24	VAC pulsed (triac) / 1 sec. cycle
2	24	VAC pulsed (triac) / 10 min. cycle / direct action
	(e.g., N.C. thermal valve)
3	24	VAC pulsed (triac) / 10 min. cycle / reverse action
	(e.g., N.O. thermal valve)
4	24	VAC pulsed (triac) / 15 min. cycle (e.g., mechanical
	relay such as R841)
5	N.O. contact (The contact closes when Output 1 reaches
	or exceeds set percentage. See section 4.1.)

When any setting between 1 and 4 is selected, Output 3 controls heating only, regardless of the thermostat’s mode.

When setting 5 is selected, Output 3 controls heating or cooling depending on whether the default mode has been set to heat or cool respectively (see section 4.3.1). For example, if the default mode has been set to heat mode, the contact remains opened when the thermostat is in cool mode. When the thermostat is in heat mode, the contact closes when Output 1 reaches a percentage of its capacity, set via the configuration menu.

4.6 Minimum and Maximum Setpoints

The minimum and maximum setpoints are factory-set at 50°F (10°C) and 95°F (35°C). The maximum setpoint can be set between 95°F (35°C) and “minimum setpoint + 1”. The minimum setpoint can be set between 50°F (10°C) and “maximum setpoint - 1”.

4.7 DIP Switches

Three switches at the back of the control module are used to select various options.

Temperature Display (SW1)

Selects the desired temperature display (°C or °F).

Access Mode (SW2)

Selects the operation mode (NORM) or the configuration mode (MENU).

•Place the switch to MENU to access the configuration menu.

•Place the switch to NORM for normal display.

Output 2 Type (SW6)

Sets Output 2 type (Analog or Triac).

WARNING: Place the switch according to the type of device (Analog or Triac) connected to Output 2. Failure to do so can result in thermostat damage.

5.Operation

5.1 Power-Up

Upon power-up, the thermostat undergoes a series of test before displaying the actual temperature.

Note: On the TB6980A and TB6980B models, at power-up, the message OPEN appears at the top of the screen during the calibra- tion of the damper opening. This can last up to 3 minutes.

5.2 Backlight

To turn the backlight on, press any button. The display will illuminate for 12 seconds.

5.3 Temperature Display and Setting

The thermostat usually displays the actual temperature. To view the

setpoint, press once on one of the buttons. The setpoint appears for 5 seconds and is indicated by the display. During the setpoint display, press one of the buttons to change it.

Note: The temperature setpoint is automatically increased or decreased by 2°F (1°C) when the controller switches to heating mode or to cooling mode respectively. For example, if the setpoint is at 77°F (25°C) in heating mode, it will become 79°F (26°C) in cool- ing mode and will return to 77°F (25°C) when the controller is back in heating mode.

5.4 Output Display

The bar graph represents the voltage for an analog out- put or the duty cycle for a triac output. The bar graph usually shows Output 1 power (% of damper opening).

To view Output 2 or 3, press Override for 2 seconds to enter the diagnostic mode. Press Override momentarily to switch between the three output graphs. To exit the diagnostic mode, press Override for 2 seconds or wait for 1 minute for the mode to exit automatically.

5.5 Mode Changeover

The thermostat can switch between heat mode and cool mode either via:

•the automatic changeover

•the changeover input

TB6980/TB7980 5/6