Centralised Air Conditioning Controllers

AT-50B Advanced Touch Controller

The Advanced Touch Controller AT-50B enables the control of 50 units. It has a 5-inch colour LCD touch panel with a back-light that makes it easy to see and control units. AT-50B also has functions such as weekly schedule and night setback that help provide for maximum comfort and increased energy savings, from a simple easy to use functional controller.

Auto (dual set point) mode

Auto (dual set point) mode

When the operation mode is set to the auto (dual set point) mode, two set temperatures (one each for cooling and one for heating) can be set. This allows for a more suitable set temperature when in each mode with a pre-set but adjustable differential, providing greater comfort control and leading to energy savings.

Main system controller/sub system controller

AT-50B can be set to Sub System controller. The system designates functions when connecting multiple system controllers, with many functions such as “main” and set the system controllers with few functions as the “Sub”.

Night setback function

Night setback function

This function allows for a room maximum and minimum temperature setting to keep the desired room temperature within set limits when the units are not in operation, during the time this function is enabled. This is not only for the comfort environment but also for assisting with saving energy.

Control of general equipment using DIDO controller

Control third-party equipment using a DIDO controller when the optional PAC-YG66MCA interface is connected.

Weekly and daily schedule

Weekly and daily schedule

5 patterns of one day and 12 patterns of weekly schedule (16 settings max. per pattern). Two types of weekly schedules can be set.

System changeover

Operation mode can be switched depending on the indoor temperature setting and target temperature of each group or a representative indoor unit.

Other Features

  • Touch screen control of up to 50 units
  • Weekly and daily schedule
  • Night setback
  • Auto (dual set point) compatibility mode
  • Control of general equipment
  • Main system controller/sub system controller
Item Description Operations Display
Permit / Prohibit The ON/OFF, operation mode, setting temperature, fan speed, air direction, filter sign reset operations, and timer using the local remote controllers can be prohibited.

Only ON/OFF and filter reset can be prohibited for the LOSSNAY group.

*The settable items vary depending on the models.

Operation Lock The operation lock can be set to the input operation of AT-50B.

Each button can be set. (Function Button 1, Function Button 2, Collective ON/OFF, Touch Panel)

Each function can be set. (Operation mode, Setting temperature, Fan speed, Menu button)

The password for the lock release can be set

Error Display


When an error is currently occurring on an air conditioner unit, the afflicted unit and the error code are displayed.

* When an error occurs, the “ON/OFF” LED flashes. The operation monitor screen show abnormal icon over the unit. The error monitor screen shows the abnormal unit address and error code. The error log monitor screen shows the time and date, the abnormal unit address, error code and source of detection.

× ☐•
Ventilation (independent) Switches the mode “Bypass/Heat recovery/Auto” for LOSSNAY groups.
Ventilation (interlocked) The LOSSNAY will run in interlock with the operation of indoor unit.

The mode cannot be changed. The LED will turn ON during operation after interlocking



Batch-setting to temperature range limit at cooling, heating, and auto mode.
Specific mode operation

prohibit (Cooling prohibit,

heating prohibit, cooling/

heating prohibit)

When set as the main controller, operation of the following modes with the local remote controllers can be prohibited.

When cooling is prohibited: Cooling, dry, automatic can not be chosen.

When heating is prohibited: Heating, automatic can not be chosen.

When cooling/heating is prohibited: Cooling, dry, heating, automatic can not be chosen.

External input

(Emergency stop input, etc.)

The following input with level signals or pulse signals are available.

Level signal: “Emergency stop input” or “Collective ON/OFF”

Pulse signal: “Collective ON/OFF” or “Local remote controller prohibit/permit”

One input can be selected from those above.

* An external input/output adapter {PAC-YT41HAA (sold separately)} is required.

Relays and DC power supply or other devices must be prepared at the site.

External output

(Error output, operation output)

“ON/OFF” and “error/normal” are output with the level signal.

* An external input/output adapter {PAC-YT41HAA, PAC-YT51HAA (sold separately)} is required.

Relays and DC power supply or other devices must be prepared at the site.

Checking the Gas Amount Use this function to check for refrigerant leak from the outdoor unit.

* When this function is used, the gas amount checking function of the outdoor unit cannot be used.

This function is for CITY MULTI R2 and Y (PUMY is excluded.) series only.

Schedule operation Weekly schedule setting up to 12 pattern is available.

In one pattern, up to 16 setting of “ON/OFF,” “Operation mode,” “Set Temperature,” “Fan speed,” “Air flow direction” and “Permit/Prohibit local operation” can be scheduled.

Two types of weekly schedule (Summer/Winter) can be set. Today’s schedule setting up to 5 pattern is available.


KEY:  ☐ Each unit ✴ Each group  • Group or Collective  × Not Available




City Multi

Explore the CITY MULTI commercial air conditioning range.


User Manual

AT-50B Controller

AT-50B Advanced Touch Controller User Manual.


Installation Manual

AT-50B Controller

AT-50B Advanced Touch Controller Installation Manual.



AT-50B Controller

Explore the features of the AT-50B Advanced Touch Controller.