Toyotomi MTN-MTG A128FS User manual

Service Manual
MODEL:
MTN-MTG A128FS
MTN-MTG A135FS

CONTENTS
1. Precaution.................................................................................................................................................... 1
1.1 Safety Precaution ........................................................................................................................1
1.2 Warning .......................................................................................................................................1
2. Function........................................................................................................................................................ 6
3. Dimension .................................................................................................................................................... 9
3.1 Indoor Units.................................................................................................................................9
3.2 Outdoor Units ............................................................................................................................11
4. Refrigerant Cycle Diagram ....................................................................................................................... 12
5. Wiring Diagram.......................................................................................................................................... 13
5.1 Indoor Units...............................................................................................................................13
5.2 Outdoor Units ............................................................................................................................17
6. Installation details...................................................................................................................................... 25
6.1 Wrench torque sheet for installation ..........................................................................................25
6.2 Connecting the cables...............................................................................................................25
6.3 Pipe length and the elevation ....................................................................................................26
6.4 Installation for the first time........................................................................................................27
6.5 Adding the refrigerant after running the system for many years ................................................30
6.6 Re-installation while the indoor unit need to be repaired...........................................................31
6.7 Re-installation while the outdoor unit need to be repaired.........................................................33
7. Operation characteristics ......................................................................................................................... 35
8. Electronic function.................................................................................................................................... 36
8.1 Abbreviation ..............................................................................................................................36
8.2 Display function.........................................................................................................................36
8.3 Main Protection .........................................................................................................................37
8.4 Operation Modes and Functions ...............................................................................................37
9. Troubleshooting......................................................................................................................................... 49
9.1 Indoor unit error display.............................................................................................................49
9.2 Diagnosis and Solution..............................................................................................................50

1
1. Precaution
1.1 Safety Precaution
To prevent injury to the user or other people and property damage, the following
instructions must be followed.
Incorrect operation due to ignoring instruction will cause harm or damage.
Before service unit, be sure to read this service manual at first.
1.2 Warning
¾Installation
Do not use a defective or underrated circuit breaker. Use this appliance on a dedicated
circuit.
There is risk of fire or electric shock.
For electrical work, contact the dealer, seller, a qualified electrician, or an Authorized
service center.
Do not disassemble or repair the product, there is risk of fire or electric shock.
Always ground the product.
There is risk of fire or electric shock.
Install the panel and the cover of control box securely.
There is risk of fire of electric shock.
Always install a dedicated circuit and breaker.
Improper wiring or installation may cause fore or electric shock.
Use the correctly rated breaker of fuse.
There is risk of fire or electric shock.
Do not modify or extend the power cable.
There is risk of fire or electric shock.
Do not install, remove, or reinstall the unit by yourself(customer).
There is risk of fire, electric shock, explosion, or injury.
Be caution when unpacking and installing the product.
Sharp edges could cause injury, be especially careful of the case edges and the fins on the

2
condenser and evaporator.
For installation, always contact the dealer or an Authorized service center.
There is risk of fire, electric shock, explosion, or injury.
Do not install the product on a defective installation stand.
It may cause injury, accident, or damage to the product.
Be sure the installation area does not deteriorate with age.
If the base collapses, the air conditioner could fall with it, causing property damage, product failure,
and personal injury.
Do not let the air conditioner run for a long time when the humidity is very high and a
door or a window is left open.
Moisture may condense and wet or damage furniture.
Take care to ensure that power cable could not be pulled out or damaged during
operation.
There is risk of fire or electric shock.
Do not place anything on the power cable.
There is risk of fire or electric shock.
Do not plug or unplug the power supply plug during operation.
There is risk of fire or electric shock.
Do not touch (operation) the product with wet hands.
There is risk of fire or electric shock.
Do not place a heater or other appliance near the power cable.
There is risk of fire and electric shock.
Do not allow water to run into electric parts.
It may cause fire, failure of the product, or electric shock.
Do not store or use flammable gas or combustible near the product.
There is risk of fire or failure of product.
Do not use the product in a tightly closed space for a long time.
Oxygen deficiency could occur.
When flammable gas leaks, turn off the gas and open a window for ventilation before
turn the product on.
Do not use the telephone or turn switches on or off.

3
There is risk of explosion or fire.
If strange sounds, or small or smoke comes from product. Turn the breaker off or
disconnect the power supply cable.
There is risk of electric shock or fire.
Stop operation and close the window in storm or hurricane. If possible, remove the
product from the window before the hurricane arrives.
There is risk of property damage, failure of product, or electric shock.
Do not open the inlet grill of the product during operation. (Do not touch the electrostatic
filter, if the unit is so equipped.)
There is risk of physical injury, electric shock, or product failure.
When the product is soaked (flooded or submerged), contact an Authorized service
center.
There is risk of fire or electric shock.
Be caution that water could not enter the product.
There is risk of fire, electric shock, or product damage.
Ventilate the product from time to time when operating it together with a stove, etc.
There is risk of fire or electric shock.
Turn the main power off when cleaning or maintaining the product.
There is risk of electric shock.
When the product is not be used for a long time, disconnect the power supply plug or
turn off the breaker.
There is risk of product damage or failure, or unintended operation.
Take care to ensure that nobody could step on or fall onto the outdoor unit.
This could result in personal injury and product damage.
¾CAUTION
Always check for gas (refrigerant) leakage after installation or repair of product.
Low refrigerant levels may cause failure of product.
Install the drain hose to ensure that water is drained away properly.
A bad connection may cause water leakage.
Keep level even when installing the product.

4
It can avoid vibration of water leakage.
Do not install the product where the noise or hot air from the outdoor unit could damage
the neighborhoods.
It may cause a problem for your neighbors.
Use two or more people to lift and transport the product.
Avoid personal injury.
Do not install the product where it will be exposed to sea wind (salt spray) directly.
It may cause corrosion on the product. Corrosion, particularly on the condenser and evaporator fins,
could cause product malfunction or inefficient operation.
¾Operational
Do not expose the skin directly to cool air for long periods of time. (Do not sit in the
draft).
This could harm to your health.
Do not use the product for special purposes, such as preserving foods, works of art, etc.
It is a consumer air conditioner, not a precision refrigerant system.
There is risk of damage or loss of property.
Do not block the inlet or outlet of air flow.
It may cause product failure.
Use a soft cloth to clean. Do not use harsh detergents, solvents, etc.
There is risk of fire, electric shock, or damage to the plastic parts of the product.
Do not touch the metal parts of the product when removing the air filter. They are very
sharp.
There is risk of personal injury.
Do not step on or put anything on the product. (outdoor units)
There is risk of personal injury and failure of product.
Always insert the filter securely. Clean the filter every two weeks or more often if
necessary.
A dirty filter reduces the efficiency of the air conditioner and could cause product malfunction or
damage.
Do not insert hands or other object through air inlet or outlet while the product is

5
operated.
There are sharp and moving parts that could cause personal injury.
Do not drink the water drained from the product.
It is not sanitary could cause serious health issues.
Use a firm stool or ladder when cleaning or maintaining the product.
Be careful and avoid personal injury.
Replace the all batteries in the remote control with new ones of the same type. Do not
mix old and mew batteries or different types of batteries.
There is risk of fire or explosion.
Do not recharge or disassemble the batteries. Do not dispose of batteries in a fire.
They may burn of explode.
If the liquid from the batteries gets onto your skin or clothes, wash it well with clean
water. Do not use the remote of the batteries have leaked.
The chemical in batteries could cause burns or other health hazards
The designs, and information in this book are subject to change without notice for product improvement.

7
Maintain the room temperature in accordance
with the setting temperature.
The mode can be change by the
room temperature.
The louver can be set at the desired position
or swing up and down automatically
The function is usually used in rainy
days in springtime or damp areas.
Turbo, high, med, low, breeze.
Prevent the water being f
r
ozen on evaporator by sensing
the evaporator pipe temperature in cooling mode
Room temperature sensor.
Pipe temperature sensor.
Indoor units
Operation by remote controller
Sensing by room temperature
Room temperature control
Anti-freezing control in cooling
Time Delay Safety control
Indoor fan speed control
Sleep mode auto control
Independent dehumidification
Air flow Direction control
Auto mode Flexible wiring connection
Self-diag. function
Auto-restart function
Timer function

8
It protects the valves and prevents water from dripping.
Outdoor units
Power relay control
Valve protection cover
Made from electrolytic zinc steel sheet and anti-rust coated components.
Low noise air flow system
Anti-rust cabinet

9
3. Dimension
3.1 Indoor Units
Figure 1 e 2:
Figure Models W H D
Figure 1 MTN A128FS 710 250 189
Figure 2 MTN A135FS
790 275 196

11
3.2 Outdoor Units
More than 30cm
More than 60cm
More than 70cm
More than 30cm
More than 60cm
(Service space
Fenceor
obstacles
Model W D H W1 A B
MTG A128FS 700
780
240
250
540
540
757
843
458
549
250
276
MTGA135FS

12
4. Refrigerant Cycle Diagram
Heating pump mode：

13
5. Wiring Diagram
5.1 Indoor Units
MTN A135FS
MTN A128FS

17
5.2 Outdoor Units
MTN A128FS, MTN A135FS

25
6. Installation details
6.1 Wrench torque sheet for installation
Outside diameter Torque Additional
tightening torque
mm inch N.cm N.cm
Ф6.35 1/4 1500
(153kgf.cm)
1600
(163kgf.cm)
Ф9.52 3/8 2500
(255kgf.cm)
2600
(265kgf.cm)
Ф12.7 1/2 3500
(357kgf.cm)
3600
(367kgf.cm)
Ф16 5/8 4500
(459kgf.cm)
4700
(479kgf.cm)
6.2 Connecting the cables
The power cord of connect should be selected according to the following specifications sheet.
Rated current of appliance Nominal cross-sectional area (mm²)
>3 and ≤6 0.75
>6 and ≤10 1.0
>10 and ≤16 1.5
>16 and ≤25 2.5
The cable size and the current of the fuse or switch are determined by the maximum current indicated
on the nameplate which located on the side panel of the unit. Please refer to the nameplate before
selecting the cable, fuse and switch.

26
6.3 Pipe length and the elevation
The pipe length and refrigerant amount:
Model Connective pipe length Air purging
Additional amount of
refrigerant
All Less than 5m Use vacuum pump ------------------
9k,12k More than 5m Use vacuum pump (Pipe length – 5) × 20g/m
Model
Standard
length
(m)
Max.
Elevation
B (m)
Max.
Length
A (m)
9k,12k 5 8 20
Caution:
Capacity test is based on standard length and maximum allowance length is based on system
reliability.
Oil trap should be installed per 3-5 meters.

27
6.4 Installation for the first time
Air and moisture in the refrigerant system have undesirable effects as below:
● Pressure in the system rises.
● Operating current rises.
● Cooling or heating efficiency drops.
● Moisture in the refrigerant circuit may freeze and block capillary tubing.
● Water may lead to corrosion of parts in the refrigerant system.
Therefore, the indoor units and the pipes between indoor and outdoor units must be leak tested
and evacuated to remove gas and moisture from the system.
Gas leak check (Soap water method):
Apply soap water or a liquid neutral detergent on the indoor unit connections or outdoor unit
connections by a soft brush to check for leakage of the connecting points of the piping. If bubbles
come out, the pipes have leakage.
1. Air purging with vacuum pump
1) Completely tighten the flare nuts of the indoor and outdoor units, confirm that both the 2-way and
3-way valves are set to the closed position
2) Connect the charge hose with the push pin of handle lo to the 3-way valves gas service port..
3) Connect the charge hose of handle hi connection to the vacuum pump.
4) Fully open the handle Lo of the manifold valve.
5) Operate the vacuum pump to evacuate.
6) Make evacuation for 30 minutes and check whether the compound meter indicates -0.1Mpa. If
(Indoor unit) (Liquid side)
(Gas side)
Vacuum
pump
Vacuum
pump
Lo Hi
Handle Hi
Two-way valve
Close
Manifold valve
Compound mete
r
Pressure
gauge
20Pa
Handle Lo
Charge hose Charge hose
(Outdoor unit)
Close
Three-way valve

28
the meter does not indicate -0.1Mpa after pumping 30 minutes, it should be pumped 20 minutes more. If
the pressure can’t achieve -0.1Mpa after pumping 50 minutes, please check if there are some leakage
points.
Fully close the handle Lo valve of the manifold valve and stop the operation of the vacuum pump.
Confirm that the gauge needle does not move (approximately 5 minutes after turning off the vacuum
pump).
7) Turn the flare nut of the 3-way valves about 45° counterclockwise for 6 or 7seconds after the gas
coming out, then tighten the flare nut again. Make sure the pressure display in the pressure indicator is
a little higher than the atmosphere pressure. Then remove the charge hose from the 3 way valve.
8) Fully open the 2 way valve and 3 way valve and securely tighten the cap of the 3 way valve.
2. Air purging by refrigerant
Procedure:
1). Confirm that both the 2-way and 3-way valves are set to the closed position.
2). Connect the charge set and a charging cylinder to the service port of the 3-way valve.
3). Air purging
Open the valves on the charging cylinder and the charge set. Purge the air by loosening the flare nut on
the 2-way valve approximately 45’ for 3 seconds then closing it for 1 minute; repeat 3 times.
After purging the air, use a torque wrench to tighten the flare nut on the 2-way valve.
4). Check the gas leakage
Check the flare connections for gas leakage.
5). Discharge the refrigerant

29
Close the valve on the charging cylinder and discharge the refrigerant by loosening the flare nut on the
2-way valve approximately 45’ until the gauge indicates 0.3 to 0.5 Mpa.
6). Disconnect the charge set and the charging cylinder, and set the 2-way and 3-way valves to the open
position.
Be sure to use a hexagonal wrench to operate the valve stems.
7). Mount the valve stems nuts and the service port cap.
Be sure to use a torque wrench to tighten the service port cap to a torque 18N∙m.
Be sure to check the gas leakage.
3. Adding the refrigerant if the pipe length >5m
Procedure:
1). Connect the charge hose to the charging cylinder, open the 2-way valve and the 3-way valve.
Connect the charge hose which you disconnected from the vacuum pump to the valve at the bottom of
the cylinder. If the refrigerant is R410A, make the cylinder bottom up to ensure the liquid charge.
2). Purge the air from the charge hose
Open the valve at the bottom of the cylinder and press the check valve on the charge set to purge the
air (be careful of the liquid refrigerant).
3) Put the charging cylinder onto the electronic scale and record the weight.
4) Operate the air conditioner at the cooling mode.
5) Open the valves (Low side) on the charge set and charge the system with liquid refrigerant.
Electronic scale

30
6).When the electronic scale displays the proper weight (refer to the table), disconnect the charge hose
from the 3-way valve’s service port immediately and turn off the air conditioner before disconnecting the
hose.
7). Mount the valve stem caps and the service port
Use torque wrench to tighten the service port cap to a torque of 18N.m.
Be sure to check for gas leakage.
6.5 Adding the refrigerant after running the system for many years
Procedure:
1). Connect the charge hose to the 3-way service port, open the 2-way valve and the 3-way valve.
Connect the charge hose to the valve at the bottom of the cylinder. If the refrigerant is R410A, make
the cylinder bottom up to ensure liquid charge.
2). Purge the air from the charge hose
Open the valve at the bottom of the cylinder and press the check valve on the charge set to purge the
air (be careful of the liquid refrigerant).
3) Put the charging cylinder onto the electronic scale and record the weight.
4) Operate the air conditioner at the cooling mode.
5) Open the valves (Low side) on the charge set and charge the system with liquid refrigerant.
Electronic scale