Mitsubishi Electric MFZ-KJ25VE, Installation Manual

En-

ContEnts

1.  BEFORE INSTALLATION ....................................1
2.  INDOOR UNIT INSTALLATION ...........................3
3.  OUTDOOR UNIT INSTALLATION .......................6
4.  PURGING PROCEDURES, LEAK TEST, AND 

TEST RUN ...........................................................7

5.  PUMPING DOWN ................................................7

1. BEFoRE InstallatIon

1-1. tHE FolloWInG sHoulD alWaYs BE oBsERVED FoR saFEtY

•  Be sure to read “THE FOLLOWING SHOULD ALWAYS BE OBSERVED FOR SAFETY” before installing the air conditioner.

•  Be sure to observe the warnings and cautions specified here as they include important items related to safety.

•  After reading this manual, be sure to keep it together with the OPERATING INSTRUCTIONS for future reference.

1-2. sElECtInG tHE InstallatIon loCatIon

CAUTION

(Could lead to serious injury in particular environments when operated incorrectly.)

Required tools for Installation

Phillips screwdriver
Level
Scale

Utility knife or scissors

25, 35 class 65 mm/50 
class 75 mm hole saw
Torque wrench

Wrench (or spanner)

4 mm hexagonal wrench
Flare tool for R410A
Gauge manifold for R410A
Vacuum pump for R410A
Charge hose for R410A
Pipe cutter with reamer

n

 Do not install the unit by yourself (user).

Incomplete installation could cause fire, electric 

shock,  injury  due  to  the  unit  falling,  or  leakage  of 

water. Consult the dealer from whom you purchased 

the unit or a qualified installer.

n

 Perform the installation securely referring to the 

installation manual.

Incomplete installation could cause fire, electric 

shock,  injury  due  to  the  unit  falling,  or  leakage  of 

water. 

n

 When installing the unit, use appropriate protec-

tive equipment and tools for safety.

  Failure to do so could cause injury.

n

 Install the unit securely in a place which can 

bear the weight of the unit.

If the installation location cannot bear the weight of 

the unit, the unit could fall causing injury.

n 

Electrical work should be performed by a quali-

fied, experienced electrician, according to the 

installation manual. Be sure to use an exclusive 

circuit. Do not connect other electrical appli-
ances to the circuit.

  If the capacity of the power circuit is insufficient or 

there is incomplete electrical work, it could result in 

a fire or an electric shock.

n

 Earth the unit correctly.

Do not connect the earth to a gas pipe, water pipe, 
lightning rod or telephone earth. Defective earthing 
could cause electric shock.

n 

Do not damage the wires by applying excessive 

pressure with parts or screws.

  Damaged wires could cause fire or electric shock.

n 

Be sure to cut off the main power in case of set-
ting up the indoor P.C. board or wiring works.

Failure to do so could cause electric shock.

n

  Use the specified wires to connect the indoor 

and outdoor units securely and attach the wires 

firmly to the terminal block connecting sections 

so the stress of the wires is not applied to the 

sections. Do not extend the wires, or use inter

-

mediate connection.

Incomplete connecting and securing could cause 

fire.

n 

Do not install the unit in a place where inflam

-

mable gas may leak.

If gas leaks and accumulates in the area around the 
unit, it could cause an explosion.

n

 Do not use intermediate connection of the 

power cord or the extension cord and do not 

connect many devices to one aC outlet.

  It could cause a fire or an electric shock due to de

-

fective contact, defective insulation, exceeding the 
permissible current, etc.

n 

Be sure to use the parts provided or specified 

parts for the installation work.

  The use of defective parts could cause an injury or 

leakage of water due to a fire, an electric shock, the unit 

falling, etc.

n 

When plugging the power supply plug into the 
outlet, make sure that there is no dust, clogging, 
or loose parts in both the outlet and the plug. Make 
sure that the power supply plug is pushed com-
pletely into the outlet.

If there is dust, clogging, or loose parts on the power 

supply plug or the outlet, it could cause electric shock 

or fire. If loose parts are found on the power supply 

plug, replace it.

n 

attach the electrical cover to the indoor unit and 
the service panel to the outdoor unit securely.

If the electrical cover of the indoor unit and/or the serv-

ice panel of the outdoor unit are not attached securely, 

it could result in a fire or an electric shock due to dust, 

water, etc.

n 

When installing, relocating, or servicing the unit, 
make sure that no substance other than the 

specified refrigerant (R410A) enters the refriger

-

ant circuit.

  Any presence of foreign substance such as air can 

cause  abnormal  pressure  rise  and  may  result  in 

explosion or injury. The use of any refrigerant other 

than  that  specified  for  the  system  will  cause  me

-

chanical failure, system malfunction, or unit break

-

down. In the worst case, this could lead to a serious 

impediment to securing product safety.

n 

Do  not  discharge  the  refrigerant  into  the  atmos-
phere. If refrigerant leaks during installation, venti-
late the room.

  If  refrigerant  comes  in  contact  with  a  fire,  harmful 

gas could be generated. 

n 

Check that the refrigerant gas does not leak 
after installation has been completed.

If refrigerant gas leaks indoors, and comes into 

contact with the flame of a fan heater, space heater, 

stove, etc., harmful substances will be generated.

n 

use appropriate tools and piping materials for 
installation.

The pressure of R410A is 1.6 times more than R22. 
Not using appropriate tools or materials and incom-
plete installation could cause the pipes to burst or 

injury. 

n 

When pumping down the refrigerant, stop the 
compressor before disconnecting the refriger-
ant pipes.

If the refrigerant pipes are disconnected while the 
compressor is running and the stop valve is open, 
air could be drawn in and the pressure in the refrig-

eration  cycle  could  become  abnormally  high.  This 

could cause the pipes to burst or injury.

n 

When installing the unit, securely connect the 
refrigerant pipes before starting the compres-
sor.

If the compressor is started before the refrigerant 
pipes are connected and when the stop valve is 
open, air could be drawn in and the pressure in the 

refrigeration  cycle  could  become  abnormally  high. 

This could cause the pipes to burst or injury.

n 

Fasten a flare nut with a torque wrench as speci

-

fied in this manual.

  If  fastened  too  tight,  a  flare  nut  may  break  after  a 

long period and cause refrigerant leakage.

n 

the unit shall be installed in accordance with 
national wiring regulations.

n

   Install an earth leakage breaker depending on 

the installation place.

If an earth leakage breaker is not installed, it could 
cause electric shock.

n

 Perform  the  drainage/piping  work  securely  ac-

cording to the installation manual.

If there is defect in the drainage/piping work, water 
could drop from the unit, soaking and damaging 
household goods.

n

  Do not touch the air inlet or the aluminum fins 

of the outdoor unit.

  This could cause injury.

n

 Do not install the outdoor unit where small ani-

mals may live.

If small animals enter and touch the electric parts 
inside the unit, it could cause a malfunction, smoke 

emission, or fire. Also, advise user to keep the area 

around the unit clean. 

WARNING

(Could lead to death, serious injury, etc.)

 ENGLISH

InDooR unIt 

•  Where airflow is not blocked.

•  Where air spreads over the entire room.
•  Rigid wall without vibration.
•  Where it is not exposed to direct sunshine. Do not 

expose to direct sunshine also during the period fol-
lowing unpacking to before use.

•  Where easily drained.

•  At  a  distance  1  m  or  more  away  from  your  TV  and 

radio. Operation of the air conditioner may interfere 

with  radio  or  TV  reception.  An  amplifier  may  be  re

-

quired for the affected device.

•  In a place as far away as possible from fluorescent 

and incandescent lights (so the infrared remote con-

trol can operate the air conditioner normally).

•  Where the air filter can be removed and replaced 

easily.

REMotE ContRollER 

•  Where it is easy to operate and easily visible.

•  Where children cannot touch it.
•  Select the position where the indoor unit can receive 

the signal from the remote controller properly. Check 

that signals from the remote controller are surely re

-

ceived by the indoor unit from that position (‘beep’ or 

‘beep beep’ receiving tone sounds). After that, attach 

remote controller holder to a pillar or wall and install 
wireless remote controller.

note: 

In  rooms  where  inverter  type  fluorescent  lamps  are 

used, the signal from the wireless remote controller may 

not be received.

outDooR unIt

•  Where it is not exposed to strong wind.

•  Where airflow is good and dustless.

•  Where rain or direct sunlight can be avoided as much 

as possible.

•  Where  neighbours  are  not  annoyed  by  operation 

sound or hot air.

•  Where rigid wall or support is available to prevent the 

increase of operation sound or vibration.

•  Where there is no risk of combustible gas leakage.
•  When installing the unit at a high level, be sure to 

secure the unit legs.

•  Where it is at least 3 m away from the antenna of 

TV set or radio. Operation of the air conditioner may 

interfere with radio or TV reception in areas where re-

ception is weak. An amplifier may be required for the 

affected device.

•  Install the unit horizontally.

•  Please install it in an area not affected by snowfall or 

blowing snow. In areas with heavy snow, please in

-

stall a canopy, a pedestal and/or some baffle boards.

note:

It is advisable to make a piping loop near outdoor unit 
so as to reduce vibration transmitted from there.

note: 

When operating the air conditioner in low outside tem-
perature, be sure to follow the instructions described 
below.
•  Never install the outdoor unit in a place where 

its air inlet/outlet side may be exposed directly to 

wind.

•  To prevent exposure to wind, install the outdoor 

unit with its air inlet side facing the wall.

•  To prevent exposure to wind, it is recommended 

to install a baffle board on the air outlet side of the 

outdoor unit.

Avoid the following places for installation where air 
conditioner trouble is liable to occur.

•  Where flammable gas could leak.

•  Where there is much machine oil.

•  Where  oil  is  splashed  or  where  the  area  is  filled 

with  oily  smoke  (such  as  cooking  areas  and  fac

-

tories, in which the properties of plastic could be 

changed and damaged).

•  Salty places such as the seaside.

•  Where sulfide gas is generated such as a hot 

spring.

•  Where  there  is  high-frequency  or  wireless  equip

-

ment.

•  Where there is emission of high levels of VOCs, 

including  phthalate  compounds,  formaldehyde, 

etc., which may cause chemical cracking.

Model names are indicated in 1-3.

When installing multi units, refer to 
the installation manual of the multi 
unit for outdoor unit installation.

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2014/02/07   15:44:57