background image

– 5 –

The figure below shows the M-NET transmission wiring diagram for City Multi air conditioners.

The maximum length of centralized control M-NET transmission line and the indoor-outdoor transmission line per system can be expressed in 
the following formulas. Labels "a through g" represent the sections of wiring in the system in the figure below. These limits ensure normal signal 
communication over the M-NET transmission line.
If the line length exceeds the maximum length, M-NET signal attenuation can occur, rendering normal communication and control impossible.

a+b+d+e(f) 

500 m (1640 ft)

a+b+c+g 

500 m (1640 ft)

e(f)+d+c+g 

500 m (1640 ft)

The maximum length of local remote controller cable is 10 m (32 ft). The length that exceeds 10 m (32 ft) must be included in the maximum total 
line length 500 m (1640 ft).

1-6. Installation

1. Field-supplied parts

The following parts are required to install the controller.

2. Required tools

• A knife or nippers        • Crosshead driver

3. Installation methods

Follow the instructions provided for the selected installation option.

(a) Wall-embedded installation using an electric box
(b) Wall-surface installation

(b-1) To route the cable through the wall 
(b-2) To route the cable along the wall surface

4. Preparation

(1) Install a breaker on the power supply unit side before installing the controller.

(2) Select an installation site for the AT-50A.

• Install the controller at the user's eye level for easy operation.
• Ensure there is enough clearance space as shown in the figure at right.
• Ensure there is enough clearance space to allow for easy access to the panel and the 

buttons.

(3) Bring the cable end up to the controller.

Ensure the M-NET transmission cables and external input/output cables are long enough to reach 
the controller. Have extra cables to extend these cables as necessary.

• To install the controller according to the instructions provided in sections (a) and (b-1) above

Include an extra 30 cm (12 in) of cable to provide adequate slack in the cable. 
Remove the sheath on the M-NET transmission cable up to 20 cm (8 in) from the end.

• To install the controller according to the instructions provided in section (b-2) above 

Include an extra 15 cm (6 in) of cable to provide adequate slack in the cable. 
Remove the sheath on the M-NET transmission cable up to 10 cm (4 in) from the end.

(4) Prepare the AT-50A.

Unscrew the screw at the bottom of the controller, and 
remove the cover.
To route the cable along the wall surface, cut out the 
rectangle knockout hole (18 mm (W) x 9 mm (D)) at 
the top of the controller with a knife or a nipper (shown 
as the shaded area in the figure below at right).

Parts

Qty.

Note

Triple electric box

1

Not required for wall-surface installation

Thin metal conduit

As appropriate

Lock nut and bushing

As appropriate

M-NET cable

As appropriate

Shielded cable
CVVS, MVVS: 1.25 mm²~2 mm² (AWG16~14)
CPEVS: ø1.2 mm~ø1.6 mm (AWG16~14 or their equivalents)

a c

e

d

b

f

g

Power supply 
unit for transmission 
cable

Outdoor 

unit

Indoor unit

Indoor unit

Indoor unit

Indoor unit

Indoor unit

Outdoor 

unit

System 

controller

Centralized controller 

transmission line

M-NET 
remote 
controller

10 m (32 ft)

Indoor-outdoor 

transmission line

30

(1.3/16)

30 (1.3/16)

50 (2)

30

(1.3/16)

Unit: mm (in)

AT-50A outline

Note

Note

Refer to section 1-7 "Using external 
input/output" for how to connect 
external input/output signal cables.

Do not push the shield wire into or 
connect it to the AT-50A. Trim the 
shield wire, cover it with vinyl 
insulating tape, and leave it 
outside the controller.

Summary of Contents for AT-50A

Page 1: ...ctric shock malfunctions smoke or fire do not operate the switches buttons or touch other electrical parts with wet hands To reduce the risk of injury or electric shock before spraying a chemical around the controller stop the operation and cover the controller To reduce the risk of injury or electric shock stop the operation and switch off the power supply before cleaning maintaining or inspectin...

Page 2: ...ical noise interference To reduce the risk of electric shock shorting or malfunctions keep wire pieces and sheath shavings out of the terminal block To reduce the risk of shorting current leakage electric shock or malfunctions keep the cables out of contact with controller edges To reduce the risk of electric shock malfunctions or fire seal the gap between the cables and cable access holes with pu...

Page 3: ...e controller 1 2 6 Installation Manual This manual 1 7 Instruction Book 1 8 CD ROM Instruction Book Installation Manual 1 2 Mounting bracket 1 AT 50A Power LED Touch panel For connection to the M NET A B Terminal for connection to the M NET cable non polarized External output adapter cable access hole External input adapter cable access hole Controller cover mounting screw SD memory slot for progr...

Page 4: ...or units apply An M NET interface sold separately is required 1 50 M NET remote controller Assign an address that equals the address of the main indoor unit with the lowest address in the group plus 100 Add 150 instead of 100 to set a sub remote controller 101 200 Sub system controller Assign an address that equals the lowest number of the group to be controlled plus 200 201 250 DIDO PAC YG66DCA A...

Page 5: ...nsure the M NET transmission cables and external input output cables are long enough to reach the controller Have extra cables to extend these cables as necessary To install the controller according to the instructions provided in sections a and b 1 above Include an extra 30 cm 12 in of cable to provide adequate slack in the cable Remove the sheath on the M NET transmission cable up to 20 cm 8 in ...

Page 6: ...the terminal block M NET transmission cable is non polarized Insert the cables in the groove on the controller so they will not be pinched when the cover is installed To route the cable along the wall surface Secure the cables in place with a cable cover and seal the gap between the cable cover and the controller with putty 5 Replace the cover Snap the cover into place and attach it to the control...

Page 7: ...ue between 0 2 and 1 seconds 4 Sample circuit recommended Mode External input signal setting Notes 1 Do not use external input Factory setting 2 Emergency stop Normal operation signal level signal When the units are not operating after receiving an emergency stop signal the ON OFF operation from the local remote controller will not be allowed and the ON OFF and Prohibit Permit settings on the AT 5...

Page 8: ...during operation The maximum length of extension cable is 10 m 32 ft Use a cable of 0 3 mm 22AWG or thicker Insulate the area with vinyl tape where the controller cable and the extension cable are connected Relays lamps diode extension cables are field supplied Note The AT 50A has a slot for an SD memory card at the bottom that can be used to update software Refer to the Installation Manual for th...

Page 9: ... ON OFF Mode Set Temp and Filter Reset 12 External input mode Selects the external input mode 12 Filter sign Displays or suppresses the Filter sign on the HOME screen 12 Dry mode Includes or excludes Dry mode as an option for the operation mode 12 Set temperature range Schedule Selects the settable temperature range Standard 19 C 67 F to 28 C 83 F Low 8 C 46 F to 30 C 87 F Manual Settable to any a...

Page 10: ...enu Touch or HOME screen GRID zoom out view GRID zoom in view LIST view GROUP view Main Menu screen Login Page screen 1 Password Change screen Service Menu Service Menu screen Initial settings 1 Basic system Initial settings 2 Groups Groups Interlocked LOSSNAY Delete All System view Malfunction log Gas Amount Check Maintenance Test run Software update Button name Main Menu Service Menu Password Ch...

Page 11: ...begin the communication g The message shown above will appear on the screen displaying the initialization progress When initialization is complete the screen will automatically return to the HOME screen Initialization will take up to five minutes To change settings later perform a test run or verify the maintenance information 1 Touch MAIN MENU button on the HOME screen 2 Touch SERVICE MENU button...

Page 12: ...o ON OFF Mode Set Temp and Filter Reset External Input Mode 1 Press the External Input setting button labeled 1 in the figure to select between Not used Emergency Stop Level signal ON OFF Level signal and ON OFF Prohibit Permit Pulse signal Refer to the Installation Manual for detailed information on how to connect the AT 50A to external devices Filter Sign Display 1 Press the Filter Sign Display ...

Page 13: ...up Indoor units LOSSNAY units and general equipment cannot be combined in one group General equipment groups cannot include remote controller or system controllers Touch Page turn button to turn the pages and follow the directions below to make the settings for each group Group Name 1 Touch the Group Name Input button labeled 1 in the figure and enter the group name in the screen up to 16 characte...

Page 14: ...he Initial Settings 2 Groups button on the Service Menu and then touch the Interlocked LOSSNAY button on the Initial Settings 2 Groups screen to access the Interlocked LOSSNAY screen 1 Touch the LOSSNAY button labeled 1 in the figure On the popup window that appears check the address of the ventilation units to be interlocked with the operation of the indoor units 2 Touch the Interlocked indoor un...

Page 15: ...at support the test run function 2 Operation mode Touch this button to switch the operation mode 3 Pipe temperature The pipe temperature of the indoor unit with the lowest address in a given group will appear 4 Advanced settings Touch this button for advanced settings Display Function A Indoor temperature Indoor air temperature will appear B Unit address up down arrows Use the up down arrows to se...

Page 16: ... OK button If the message The DIP switch 4 is set to OFF appears check to make sure that the DIP switch 4 is turned to ON The DIP switch is located at the left bottom of the controller under the cover 4 Touch the OK button on the confirmation screen 5 Touch the OK button on the popup message to begin the update process 6 The lit LEDs on the three buttons F1 F2 and Collective ON OFF will indicate a...

Reviews: