Setting The Night Setback Function; When The Temperature Drops Below The Lower Limit Temperature - Mitsubishi Electric AT-50B Instruction Book

Main Menu > Operation Setting > Time and Schedule > Setback Control

Setting the Night Setback function

C
Night Setback function (hereafter abbreviated as Setback) is a function that prevents indoor dew or
extreme temperature rise by heating/cooling automatically when the room temperature goes outside
of the specific range during the set time period.
• In a group where both Air To Water (PWFY) and air conditioning units are connected to Y series
outdoor unit, Setback function may not function properly.
• When the air conditioning group with Setback function is off and when the temperature exceeds the
preset temperature, heating/cooling operation starts.
• If the room temperature is measured by the air-conditioner's suction temperature sensor, the
temperature may not be correct when the air-conditioner is inactive and the air is not fresh. When
the air-conditioner is inactive, using a remote sensor or a remote control sensor is recommended to
measure room temperature correctly.
• If the temperature setting, ON/OFF operation, or Timer (Schedule) execution is prohibited for this unit,
Setback operation cannot be used.
• If the operation mode change is prohibited or the operation mode selection is limited for this unit,
Setback function may not function properly.
When the Setback control is set, air conditioning group operates as shown below.
21ºC/69ºF
Room
temperature
Lower limit
temperature
12ºC/53ºF
Heating Heating
On Off
21ºC/69ºF

When the temperature drops below the lower limit temperature

(heating control)
If "Unscheduled" is selected, the Setback function that were set on the [Setback Control] screen will not
be executed with the pressing of the Collective Operation button.
In this case, the settings that were made on the [Collective Operation] - [Setback] screen will override
the settings made on the [Setback Control] screen, and the scheduled operation will not run.
1. Touch the C Setback Control button on the [Time
and Schedule] screen.
2. Read the pop-up message, and touch the OK
button to confirm.
Setback operation stops
(when the temperature
Setback
rise 3ºC/5.4ºF or the
operation
control time period is over)
starts.
Heating Heating
On Off
12ºC/53ºF 21ºC/69ºF
Setback control time period
Upper limit
temperature
28ºC/83ºF
Room
temperature
24ºC/75ºF
Cooling Cooling
On Off
24ºC/75ºF
Setback control time period
When the temperature rises above the upper limit temperature
(cooling control)
4
6
3ºC/5.4ºF
Setback
operation
starts.
Cooling Cooling
On Off
28ºC/83ºF 24ºC/75ºF
1
5
7
37