Mitsubishi Electric GB-24A User manual

Air-conditioner Control System
Centralized Controller
Model: GB-24A Installation Manual
Before installing the controller, please read this Installation Manual carefully to ensure proper operation.
Retain this manual for future reference.
Contents
1. Safety Precautions..................................................... 1
2. Parts List.................................................................... 3
3. Product Features ....................................................... 4
4. System Diagram ........................................................ 5
5. Installation.................................................................. 8
1. Field-supplied parts............................................... 8
2. Maximum length of M-NET transmission lines...... 8
3. Installation............................................................. 9
6. Wiring....................................................................... 12
1. Ground cable. ..................................................... 12
2. Cover removal and installation............................ 12
3. M-NET transmission line..................................... 13
4. LAN connection................................................... 13
7. Initial Setting ........................................................... 14
1. Setting the IP address with dip switches............. 15
2. Setting the service switch.................................... 15
8. Test Run .................................................................. 16
1. Collective operation, ON/OFF............................. 16
2. Service LED display............................................ 16
9. System Wiring Example........................................... 17
10. External Input/Output Usage .................................. 19
1. External signal input function .............................. 19
2. External signal output function............................ 21

1
This manual describes how to install the centralized controller and wiring. Before installing the controller, read the
section carefully to ensure proper installation.
Safety symbols used in this manual
The following symbols are used in this manual to indicate the type and severity of potential consequences that
may result when given instructions are not followed exactly as stated.
Retain the Installation Manual and the Instruction Book for future reference. Make sure both the Installation
Manual and the Instruction Book are given to any future air condition system users.
WARNING Indicates a risk of death or serious injury.
CAUTION Indicates a risk of injury or damage to the controller.
WARNING
CAUTION
1
Safety Precautions
1
Safety Precautions
The controller must be professionally installed.
Improper installation by an unqualified person may
result in electric shock or fire.
Make sure the controller is securely mounted so
that it will not fall.
Only use specified cables. Securely connect
each cable so that the weight of the cable is not
applied to the connectors.
Loose or improper connections may result in heat
generation or fire.
Do not attempt to modify or repair the controller.
Modification or improper repair may result in electric
shock or fire.
Consult your dealer when repairs are necessary.
Securely install the controller according to the
installation manual.
Improper installation may result in electric shock or
fire.
Electric work must be perform by authorized
personnel according to the local regulations and
the instructions detailed in the installation
manual.
Inadequate circuit capacity or improper installation
may result in electric shock or fire.
Ask your dealer or an authorized technician to
move the controller.
Improper installation may result in electric shock or
fire or damage to the controller.
This appliance must be grounded.
Make sure to install a ground wire.
Do not connect the ground wire to gas or water
pipes, lightning conductors or telephone grounding
lines.
Improper grounding may cause an electric shock.
Do not install the controller where there is a risk
of flammable gas.
If the leaked gas accumulates around the controller,
it may ignite and cause an explosion.
Do not use the controller in an environment high
in oil, steam, or sulfuric gas.
These substances may have adverse effects on the
performance of the controller or damage its parts.
Do not install this controller where the ambient
temperature exceeds 104ºF (40ºC) or drops
below 32ºF (0ºC).
To prevent the controller from being damaged and
malfunctioning, install it away from direct sunlight.
Do not install this controller in a place that has
the potential for steam or condensate formation.
Steam or condensate formation may cause an
electric shock or a unit malfunction.

2
CAUTION
When installing the controller in a hospital or communication facility, take appropriate measures to
reduce electrical noise interference.
Inverter equipment, generators, high-frequency medical equipment, or radio communication equipment may
interfere with the normal operation of the controller; or the electrical noise from the controller may interfere
with the medical practice or cause image distortion and static.
To prevent over-heating and fire, wire so that the
weight of the cable will not strain the connectors.
Do not expose the controller to water.
Water may damage the controller and cause an
electric shock.
Use specified wires with the proper current
carrying capacity to prevent current leakage,
over-heating, or fire.
Do not touch the PCB (Printed Circuit
Board) with your hand or a tool. Also do
not get dust on the PCB.
It may cause a fire or malfunction.
To reduce the risk of electric shock, install and
wire the unit with the power to power supply unit
turned off.
Do not install this controller where an acid,
alkaline solution, special chemical spray is
used frequently to avoid electric shock or
malfunction.
Do not press the switches with sharp objects.
It may cause an electric shock or malfunction.
To avoid causing damage or fire, do not apply an
AC voltage or a voltage higher than 30V DC to
the M-NET terminal blocks on the controller.
Do not touch the switches with wet hands.
It may cause an electric shock or malfunction.
Use a security device such as a VPN router when
connecting the GB-24A to the Internet to prevent
unauthorized access.
If no security devices are installed, the operation
settings may be changed by an unauthorized person
without the knowledge of the user.

3
*Please confirm that in addition to this Installation Manual, the following items are shipped with the unit.
* The screws for installing to the metal control panel are not included. (M4 screws)
* In addition to the parts above, a power supply unit for transmission line, which supplies the power to the centralized
controller through the transmission line, must be purchased. If the outdoor unit is a CITY MULTI R410A model, however, the
outdoor unit can also supply the power (Not applicable to the PUMY model).
*1: Each system allows the connection of only one GB-24A.
* Use PAC-SC50/51KUA (power supply unit) when multiple outdoor units are connected. Connect only the M-NET terminal
(TB2) on PAC-SC50/51KUA to the M-NET terminal on GB-24A
No. Part name Qty.
1 Centralized controller 1
2L-fitting 2
3 M3 (8mm (5/16in)) round head screw (for attaching the L-fitting) 4
4 DIN rail attachment 2
5 M3 (6mm (1/4in)) round head screw (for attaching the DIN rail attachment) 8
6 Installation manual (this book) 1
7 Instruction book 1
8 Web browser operation manual 1
9 Operation manual for Initial setting web 1
Unit that supplies the
power to GB-24A
The number of
connectable GB-24A Remarks
PAC-SC51KUA 1 unit *1 xWhen only one GB-24A unit is connected Up to two
other system controllers can be connected to the
transmission line for central control.
(Up to two ON/OFF remote controllers, up to four system
remote controllers, up to four schedule timers, or up to
four group remote controllers can be connected.)
PAC-SC50KUA 1 unit *1 xWhen only one GB-24A unit is connected Up to three
other system controllers can be connected to the
transmission line for central control.
(Up to three ON/OFF remote controllers, up to six
system remote controllers, up to six schedule timers, or
up to six group remote controllers can be connected.)
R410A CITY MULTI
outdoor unit (TB7)
(connected to the
transmission line for
central control)
1 unit x
x
*
x
Replace CN41 (power-supply switch connector) with
CN40 on only one outdoor unit.
Connectable number of indoor units will decrease by
4 units.
CITY MULTI units except the PUMY model (R410A
outdoor units only)
When multiple outdoor units are connected to the
system and the power to the outdoor unit is cut off to
which the GB-24A is connected, that GB-24A will shut
down.
CITY MULTI outdoor unit
(TB3)
(connected to
the indoor/outdoor
transmission line)
1 unit x
x
Connectable number of indoor units will decrease by
4 units.
When multiple outdoor units are connected to the
system and the power to the outdoor unit is cut off to
which the GB-24A is connected, that GB-24A will shut
down.
2Parts List

4
1. Specification
2. Outside dimensions
Fig. 3-1 Unit: in (mm)
Fig. 3-2 Unit: in (mm)
Item Contents
Interface M-NET: 30V/24V DC; 0.13/0.15A
External I/O: 12V DC or 24V DC (External power supply)
Ethernet: 10Base-T
Environmental
conditions
Temperature Operating range: 32 to 104ºF / 0 to 40ºC
Storage range: - 4 to +140ºF / -20 to +60ºC
Humidity 30-90%RH (No condensation)
Dimensions 51/8(H) x 97/8(W) x 11/2(D)in/130 (H) x 250 (W) x 38 (D) mm
Weight 21/2lb. / 1.1kg
Installation Environment In the metal control panel box (indoor)
Install this product indoors.
* This unit is installed and used in a business office, homes or equivalent
environment.
3Product Features
11/2(38)
97/8(250)
POWER LAN LINK/ACT
51/8(130)
1 2 3 4 5 6
Side view Top view
Front view
25/32
(
20
)
25/64
(
10
)
25/32
(
20
)
L-fittings

5
1. System with a power supply unit
* Address setting for each M-NET device (The address cannot be duplicated.)
Address setting method Address
Indoor unit Set an indoor unit as the master unit, and set the rest of
indoor unit sequentially address in the same group.
1-24
Outdoor unit Min. indoor unit address in same refrigerant system + 50. 51-74
BC controller/OS controller
* OS: Subsidiary Outdoor unit
Set the outdoor unit address in same refrigerant system + 1
However, for Sub-BC controller, set the minimum indoor unit
address that connects the local refrigerant piping + 50.
52-74
Mr.Slim Outdoor unit
(M-NET adapter)
Same address as indoor unit.
An M-NET adapter (sold separately) is required.
1-24
M-NET remote controller Set to the minimum indoor unit master address in the same
group + 100.
101-124
MA remote controller Address setting is unnecessary. -
OA processing unit/LOSSNAY After setting all the indoor units, set an arbitrary address. 1-24
4System Diagram
NOTE
* This diagram does not show
the AC power supply wiring.
Only the configuration for
the transmission line is
shown.
To PC
Centralized controller
Model: GB-24A
Power supply unit (optional)
Model: PAC-SC51KUA, PAC-SC50KUA
LAN
M-NET
outdoor unit
M-NET
Group 1 Group 2
Indoor unit
Local remote controller
M-NET transmission line
MA remote controller line
The numbers in the
indicate the address No.
Group 3 LOSSNAY
M-NET
outdoor unit BC controller
R2
Mr. Slim
Outdoor unit
Group 4 Group 5
Mr. Slim
Outdoor unit
M-NET adapter

6
2. System in which power is supplied from an outdoor unit
* Address setting for each M-NET device (The address cannot be duplicated.)
NOTE
* If the outdoor unit
malfunctions or is turned
off, the GB-24A that is
connected to the outdoor
unit will also shut down.
* This diagram does not show
the AC power supply wiring.
Only the configuration for
the transmission line is
shown.
To PC
Centralized controller
Model: GB-24A
LAN
M-NET
outdoor unit M-NET
Group 1 Group 2
Indoor unit
Local remote controller
M-NET transmission line
MA remote controller line
The numbers in the
indicate the address No.
Group 3 LOSSNAY
M-NET
outdoor unit BC controller
R2
Mr. Slim
Outdoor unit
Group 4 Group 5
Mr. Slim
Outdoor unit
M-NET adapter

7
NOTE
*This system controller is designed as a main controller, not as a sub controller.
xMain system controller (main SC)
The main system controller is designed to control all units, including units that other system controllers
control. When there is only one system controller in a system, it will become the main system controller.
Group setting or interlock setting can be made only with the main system controller.
xSub system controller (sub SC)
The sub system controller that controls a local area is controlled overall by the main system controller.
Control area of main SC
Control area of sub SC
Group Group
Group This system controller is designed as a main
controller, so it cannot be controlled by a main
SC (such as Gateway).

8
1. Field-supplied parts
Please obtain the following parts before unit installation.
*1: When installing DIN rail, prepare 1.38inch (35mm) DIN rail. Mounting screws for DIN rail must be also
field-supplied.
Applicable DIN rail types (IEC 60715/DIN 60715): TH35-7.5Fe, TH35-7.5Al
2. Maximum length of M-NET transmission lines
xMaximum length of M-NET transmission =1640 ft/500m *1
xMaximum power feeding length =656 ft/200m *1
Example
Field-supplied parts Specification
Attaching screws M4 screw x 4pcs (when using L-fittings) *1
Protective ground cable Use sheathed vinyl cord or wire.
Wire type : Wire should not be lighter than ordinary PVC sheathed flexible
cord IEC 60227
(designation 60227 IEC 53)
Wire size : 0.75mm2to 2mm2(AWG 18 to 14)
Wire color : green/yellow
Round terminal M4 screw size terminal (used for protective ground cable)
Transmission cable Type of the cable: Shielded cable which comply with the following specifications
or equivalent:
xCPEV: 1.2mm to 1.6mm
xCVVS: 1.25mm2to 2 mm2(AWG 16 to 14)
*CPEV: PE insulated PVC jacketed shielded communication cable
*CVVS: PVC insulated PVC jacketed shielded control cable
PE: Polyethylene PVC: Polyvinyl chloride
NOTE
* 1: Specifications do not include the remote control cables up to 32 ft (10m) in length. If the remote
control cable exceeds 32 ft (10m), the excess must be added to the total length in order to avoid
exceeding the maximum length.
5Installation
Φ
Φ
ℓ2
ℓ3
ℓ5
ℓ6
ℓ8
ℓ7
ℓ1
ℓ
4
Outdoor
unit Indoor Indoor Indoor
Indoor Indoor Indoor
Indoor Indoor Indoor
Outdoor
unit
Remote controller
Remote controller
Power
supply
unit
M-NET transmission line
(Centralized control line)
M-NET transmission line
(Indoor control line)
GB-24A

9
1) Maximum length of M-NET transmission
1 L2+L3+L4+ 1+ 2+ 3 ( 4) =1640 ft/500m
2 L2+L3+L4+ 1+ 5 =1640 ft/500m
3 L2+L3+L5+ 6+ 7 ( 8) =1640 ft/500m
4 3 ( 4)+ 2+ 1+L4+L5+ 6+ 7 ( 8) =1640 ft/500m
5 5+ 1+L4+L5+ 6+ 7 ( 8) =1640 ft/500m
2) Maximum power feeding length for the indoor control line
1 1+ 2+ 3 ( 4) =656 ft/200m
2 1+ 5 =656 ft/200m
3) Maximum power feeding length for the centralized control line
1 L1+L2 =656 ft/200m
2 L1+L3+L4 (L5) =656 ft/200m
3. Installation
Installation methods for the centralized controller GB-24A are shown below.
Method1: Horizontal installation using L-fittings
Attach two L-fittings to GB-24A using the supplied screws (Fig. 5-1), then install GB-24A (Fig. 5-2).
Install the GB-24A in a metal control panel box (steel: thickness 3/64 in (1mm) or more).
When installing follow the metal control panel box clearance space specifications as shown in the Fig. 5-2.
(Install in an area capable of withstanding a 2 1/2 lb (1.1 kg) load.)
Fig. 5-2 Unit: in (mm)
NOTE
If the remote controller cables ( 4, 8) do not exceed 32 ft (10m), the length for 4, 8 do not have to be
factored into the total length.
NOTE
Centralized controller GB-24A is not waterproof.
CAUTION
xL-fittings must be attached at two points on the unit.
xThe unit with L-fittings must be attached at four points to prevent the unit from falling.
NOTE (*1)
When connecting the ground cable after GB-24A is installed, leave some space for mounting screws.
When there is little space for mounting screws, connect the ground cable before GB-24A is installed.
13/16
(
20
)
13/16
(
20
)
2
(
50
)
13/16 (20) *1
M3
M4
11 13/32
(
290
)
Total of 4 screws
(Both sides)
Top view
Fig. 5-1

10
Method2: Vertical installation using L-fittings
After removing the screws on GB-24A, attach two L-fittings to the unit using the supplied screws (Fig. 5-3), then
install (Fig. 5-4).
Install the GB-24A in a metal control panel box (steel : thickness 3/64 in (1mm) or more).
When installing, follow the metal control panel box clearance space specifications as shown in the Fig. 5.4.
(Install in an area capable of withstanding a 2 1/2 lb (1.1 kg) load.)
(Reference) When GB-24A is installed inside the metal control board, it is recommended that it be installed
after the wiring work, so that the installation becomes easy.
Fig. 5-4 Unit: in (mm)
Method3: Installation using DIN rail
GB-24A can be attached to DIN rail (1.38inch (35mm)).
Attach DIN rail attachment to GB-24A using the supplied screws (Fig. 5-5), then install GB-24A (Fig. 5-6).
Install the GB-24A in a metal control panel box (steel : thickness 3/64 in (1mm) or more).
When installing, follow the metal control panel box clearance space specifications as shown in the Fig. 5-6.
(Install in an area capable of withstanding a 2 1/2 lb (1.1 kg) load.)
Fig. 5-5 Unit: in (mm)
CAUTION
xL-fittings must be attached at two points on the unit.
xThe unit with L-fittings must be attached at four points to prevent the unit from falling.
13/16
(
20
)
3/16
(
20
)
13/16
(
20
)
13/16
(
20
)
*1
M3 (5/16 (8))
M3
11 13/32 (290)
(Both sides)
Fig. 5-3
Front view
L-fitting
M3 (1/4 (6))
Left view Rear view
Total of 8 screws Top
Under

11
Fig. 5-6 Unit: in (mm)
Installation and removal of GB-24A when attached to DIN rail
1) Installation
Position the top of the attachment on the DIN rail, and push the bottom of the unit in the direction of the arrow
shown in the figure below.
2) Removal
Push the unit down and pull it in the direction of the arrow shown in the figure below.
CAUTION
xDIN rail attachment must be attached at four points on the unit using two M3 roundhead screws.
xTo secure, screw pitch of 7.88inch (200mm) or less is required when DIN rail is attached on the
metal control board.
xUse GB-24A in a place where it is not subjected no vibrations. Use studs as necessary to attach
GB-24A.
13/16
(
20
)
13/16
(
20
)
2 (50)
13/16 (20)
Top view
DIN rail (1.38 (35))
Fig. 5-7
CAUTION
xCheck that the attachment is secure on
the DIN rail.
Fig. 5-8
Step 1
Step 2

12
1. Ground cable
Connect the protective ground cable to the ground terminal as shown in the Fig. 6-1. Attach the ring
terminal (M4) to the ground cable, and connect the cable to the ground terminal on the unit.
2. Cover Removal and Installation
When removing the cover, remove the two mounting screws and remove it.
When installing the cover, install it by tightening the two screws.
WARNING
xAll electric work must follow local regulations.
Improper electrical work may result in electric shock or fire.
xShut off the power source of the unit and all other units to be connected to the power supply unit
before wiring.
CAUTION
xDo not connect the AC power line to the M-NET terminal blocks of this device, otherwise the unit
may fall.
6Wiring
Fig. 6-1
Protective
ground cable
Cable color
: green / yellow
Fig. 6-2

13
3. M-NET transmission line
Connect the M-NET transmission line to the A, B (non-polarity) and S (shield) terminal block, as shown in
Fig. 6-3.
4.LAN connection
Connect the LAN cable to the LAN connector of the GB-24A unit.
xField-supply the LAN cable, and use an enhanced category 5 UTP cable.
x For a description of the IP address setting method, refer to section .
xLAN is 10 BASE-T Specification.
xMaximum wiring length from HUB to GB-24A is 328 ft (100m).
xGB-24A is connected to the monitoring PC via HUB.
CAUTION
xDC power to the M-NET transmission line is supplied from either the power supply unit
PAC-SC51KUA/PAC-SC50KUA or R410A CITY MULTI outdoor unit *1. When supplying the power
from the R410A CITY MULTI outdoor unit*1 to the transmission line for central control (TB7),
disconnect the male connector from the female power supply switch connector (CN41: no power
supply) and connect it to the female power supply switch connector (CN40: power supply) on only
one of the outdoor units. For further details, refer to the transmission manual of the outdoor unit. Not
doing so may cause unit failure or fire.
*1: CITY MULTI R410A outdoor units (except PUMY model) only.
xSecurely connect the wiring using the specified cables and attach them so that the stress from the
cables is not applied to the terminal connection sections. If the cables aren’t securely attached, it
may cause heat generation, a fire, etc.
NOTE
xPerform the LAN wiring before installation, and wire up to the unit following the same method of
wiring as for the M-NET transmission line.
xWhen a LAN is already connected, choose an IP address after consulting with the system
administrator, and connect the LAN port after changing the IP address.
xSpace for the connector and wiring is required. Refer to section .
M-NET
TB7
A
B
S
PAC-
SC50
KUA
GB-24A
TB2
M-NET
PAC-
SC51
KUA
TB2
PAC-SC51KUA PAC-SC50KUA
Fig. 6-3
Outdoor
unit
Shield
Vinyl tape etc. (*1)
M-NET tranmission A, B line
(Non-polarity 24V DC or 30V DC)
Shield Vinyl tape etc. (*1)
M-NET tranmission A, B line
(Non-polarity 24V DC or 30V DC)
M-NET terminal block
(*1) Insulate the shielded wire with
vinyl tape expect for the end where
it is connected to the terminal screw.
or
5 Instalación
7 Initial Setting
LAN
5 Installation

14
Initial setting steps
Step 1: IP address setting
Step 2: Group setting
Step 3: Other settings
Step 4: Test run
Function list of GB-24A, and the Initial Setting Web.
*1: K transmission converter cannot be used. Select “Not used” for the K-control Units setting in the M-NET
Settings window.
Note
xInitial setting can be set via the web through LAN. More functions can be set with the initial setting
web.
The functions that can be initialized using this unit are described in this manual. Refer to the initial
setting web operation manuals for more information.
xThe format in which the Web page address for each GB-24A is expressed on the Initial Setting
Web, as well as the default setting user name and password are shown below.
http:// [IP address of the GB-24A]/g-50/ administrator.html
Note: For example, type “http://192.168.1.1/g-50/administrator.html” if the GB-24A IP address is
[192.168.1.1].
Items GB-24A Initial Setting
Web Remarks
M-NET address setting The default value is 0.
IP address setting
(simple setting)
*The settings of the simple setting have
the priority over other settings.
Function selection Presence/absence of K transmission
converter connection*1, local operation
prohibition setting, and external input
mode.
Group registration
Registration of interlocked
operation with the
ventilation unit
Service switch
Other settings Available functions vary depending on
the tool.
7Initial Setting
User Default
user name
Default
password
Maintenance user initial init
√
√
√
√
√
√
√
√

15
1. Setting the IP address with dip switches
IP addresses between 192.168.1.1 and 15 can be set using the 4-pin dip switch on SW2.
Set this switch before turning the power on.
2. Setting the service switch
The switches must be OFF for normal use. The switch setting change operates when the power is turned on next
time.
NOTE
xWhen setting IP addresses with the Initial Setting Web, set all four dip switches on SW2 to OFF.
xIf the IP address of GB-24A is forgotten, check the IP address that is registered on the monitoring
PC (Web). GB-24A can be started by changing the setting of SW2 on GB-24A IP address, and
using a temporary arbitrary fixed IP address. It is recommended to note the IP address on the unit,
so that the IP address of GB-24A is available at all times.
SW 2
1 2 3 4
(Inside the cover)
ON
OFF
1 2 3 4 Contents (IP address)
OFF OFF OFF OFF
Address that is set with Initial Setting Web
(Default IP address setting is 192.168.1.1
(Factory setting))
OFF OFF OFF ON Starts from 192.168.1.1
OFF OFF ON OFF Starts from 192.168.1.2
OFF OFF ON ON Starts from 192.168.1.3
OFF ON OFF OFF Starts from 192.168.1.4
OFF ON OFF ON Starts from 192.168.1.5
OFF ON ON OFF Starts from 192.168.1.6
OFF ON ON ON Starts from 192.168.1.7
ON OFF OFF OFF Starts from 192.168.1.8
ON OFF OFF ON Starts from 192.168.1.9
ON OFF ON OFF Starts from 192.168.1.10
ON OFF ON ON Starts from 192.168.1.11
ON ON OFF OFF Starts from 192.168.1.12
ON ON OFF ON Starts from 192.168.1.13
ON ON ON OFF Starts from 192.168.1.14
ON ON ON ON Starts from 192.168.1.15
SW 1
1 2
3 4
ON
OFF
Not to be used
*SW1-3 and SW1-4 are always OFF.
1 2 Contents Remarks
OFF OFF Starts with the normal
mode *This setting is for normal use.
ON OFF - Setting is prohibited.
OFF ON - Setting is prohibited.
ON ON Starts with the update
mode
*The software can be updated with
the normal mode. If the update fails,
or the software does not work
properly, use this setting to update
the software again.

16
1. Collective operation, ON/OFF
* After setting the group or interlocked setting, confirm that the controller has started up, and then perform a test
run.
* It may take approx. 10 minutes for local remote controller operation to be enabled after the power is turned ON.
In this case, press the collective ON/OFF switch on the controller to enable immediate local remote controller
operation.
(Test run procedure)
1. Turn ON the power to the controller and all the units.
2. When the LED1 on the main unit turns OFF, press SW3. The units registered in the same group will
start a group operation. When the group operation starts, the LED2 turns ON.
3. Confirm operation during the test run.
4. When each unit has been confirmed, stop the unit with the controller or local remote controller.
* Refer to the installation manual for the connected indoor unit for details on the test run method.
* The test run mode cannot be selected with a collective ON/OFF switch (SW3). The
operation mode will be the current operating mode.
2. Service LED display
The LED displays the operation status of the unit as follows
Note
xUse the local remote controller to change the mode to the “Test run” mode.
xAn operation mode other than “Test run” can be selected on the Web browser.
xThe format in which the Web page address for each GB-24A is expressed on the Web browser, as well
as the default setting user name and password are shown below. For further details, refer to the manual
for the Web browser.
http:// [IP address of the GB-24A]/administrator.html
Note: For example, type “http://192.168.1.1/administrator.html” if the GB-24A IP address is [192.168.1.1].
LED No. Items Contents
Power supply
LED
Power status ON : Power is supplied / OFF: Power is cut off
LAN LAN LINK ON : During LINK / OFF: No LINK
LAN LAN ACT Flash : During communication
/ OFF: No communication
LED1 Start-up ON : Start-up not completed / OFF: Start-up completed
LED2 Operation ON/OFF ON : 1 or more units are ON / OFF: All OFF
LED3 Error Flash : Error occurred on 1 or more units / OFF: Normal state
LED4 (not defined) -
LED5 (not defined) -
LED6 M-NET communication
(transmission)
Flash : During communication / OFF: No communication
8Test Run
SW 3
User Default
user name
Default
password
Managers administrator admin
POWER LAN LINK/ACT 1 2 3 4 5 6
Power supply
LED LAN LED 1-6

17
(1) Power supply of 24-32V DC from power supply unit PAC-SC50(51)KUA.
Power supply unit PAC-SC50(51)KUA is recommended for GB-24A. See the diagram below;
for details, please refer to the Installation Manuals of PAC-SC50(51)KUA.
9System Wiring Example
Power supply
* GB-24A requires 24-32V DC power supply (M-NET) for centralized control transmission use, operation,
and LAN function use.
LAN
Centralized controller
GB-24A
Outdoor unit
Power
Supply
Unit
Indoor unit Indoor unit
ME remote
controller
ME remote
controller
ME remote
controller
Indoor unit
Outdoor unit
LOSSNAY
LOSSNAY M-NET
remote controller
PAC-SC50KUA
or
PAC-SC51KUA
Mr. Slim
Outdoor unit
Indoor unit
MA: MA remote controller
M-NET
adapter
Fig. 9-1 Basic system with GB-24A and PAC-SC50(51)KUA.

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(2) Power supply of 30V DC from outdoor unit connector TB7.
As shown on Fig. 9-2, GB-24A receives power supply of 30V DC from R410A CITY MULTI outdoor unit
connector TB7.
If one of the outdoor units should change its power supply switch CN41 to CN40.
*NOTE: This method applies to R410A CITY MULTI outdoor unit except PUMY (S series).
(3) Power supply of 30V DC from outdoor unit connector TB3.
GB-24A can also receive power supply from R410A/R407C/R22 outdoor unit connector TB3. However, if the
outdoor unit shuts down, GB-24A will also automatically shut down. Therefore, this system is not recommended
for air conditioning system with multiple outdoor units.
TB7 TB3
TB7 TB3
CN41 CN40
CN41
Centralized controller
GB-24A
Outdoor unit
Indoor unit
ME remote
controller
Indoor unit
Centralized control
transmission line
Indoor/outdoor transmission line
Indoor/outdoor transmission line
ME remote
controller
R410A CITY MULTI
Outdoor unit
Fig. 9-2 GB-24A, TB7 system.
TB7 TB3
CN41
Centralized controller
GB-24A
Indoor unit
ME remote
controller
Indoor/outdoor transmission line
Outdoor unit
Fig. 9-3 GB-24A, TB3 system.

19
1. External signal input function
* External signal input requires the external I/O adapter (Model: PAC-YG10HA), sold separately.
Some parts, such as 12V DC or 24V DC power supply and relays, must be field-supplied.
(1) External input
Emergency stop/normal, run/stop and prohibit/enable of local remote controller operation can be controlled
for all air conditioners on a system by using a voltage (12V DC or 24V DC) contact signal from an external
source. (Select with the function select setting using the Initial Setting Web).
(2) Level signal and pulse signal (12V DC or 24V DC)
No. External signal input function Remarks
1Do not use external input signal (factory
setting)
2
Execute emergency stop/normal with
level signal
Local remote controller ON/OFF operation, and
the controller ON/OFF operation and prohibit/
enable change operations will be prohibited
during emergency stop.
3
Perform ON/OFF with level signal Local remote controller ON/OFF operation, and
the controller ON/OFF operation and prohibit/
enable change operation will be prohibited.
4Perform ON/OFF, prohibit/enable with
pulse signals
Set the pulse width while the contact is ON to 0.5 to
1 sec.
10 External Input/Output Usage
CN2
(A) Level signal
Contact ON
Contact OFF
Contact ON
Contact OFF
Contact ON
Contact OFF
Contact ON
Contact OFF
Signal 1 (run)
Signal 2 (stop)
(Example) for ON/OFF
(B) Pulse signal
Stop Run Stop
Normal Normal
Emergency
stop
0.5 to 1 sec
0.5 to 1 sec
OFF OFF
ON
* The prohibit/enable input is the same.