Mitsubishi Electric Fresh Master GUF-50RD4 User manual

Repair work must be performed by
the manufacturer, its service agent or
a similarly qualified person in order to
avoid hazards.
June 2014 No. U189-A
Model : GUF-50RD4
GUF-50RDH4
GUF-100RD4
GUF-100RDH4
GUF-100RDH4-60
FRESH MASTER
HANDBOOK
Nameplate

Contents
1. Safety precautions
.................................................................... 3-4
2. Names and functions of components .......................................... 4
3. Specifications
.............................................................................. 5
4. Outside dimensions
..................................................................... 6
5. Electrical wiring diagrams ......................................................... 7-8
6. Circuit board diagrams ........................................................... 9-10
7. Troubleshooting
.....................................................................11-17
8. Overhauling procedures ........................................................ 18-28
9. Parts catalog ........................................................................ 29-63
GUF-50RD4................................................................... 30-35
GUF-50RDH4................................................................. 36-41
GUF-100RD4................................................................. 42-47
GUF-100RDH4............................................................... 48-55
GUF-100RDH4-60 .......................................................... 56-63

─3 ─
1. Safety precautions
Warning
Modification is prohibited
Do not modify the unit.
(Failure to heed this warning may result
in electric shock, fire and/or injury.)
Electric shock
If you must inspect the circuitry while the power is
on, do not touch the live parts.
(Failure to heed this warning may result
in electric shock.)
Check insulation
Upon completing repair work, always measure the
insulation resistance. Verify that it is at least 10 MΩ
(with a 500 V DC insulation resistance tester), and
then turn on the power.
(Inadequate insulation may result in
electric shock.)
Incorrect handling of the product may
result in serious injury or death.
Do not mix anything other than the specified
coolant of the same type used in the outdoor
unit.
Do not charge any coolant different from the coolant
used in the outdoor unit.
( Failure to heed this warning may cause
the pressure inside the freezing cycle
to become abnormally high, leading to
injury or other damage. )
Use proper parts and tools
For repair, be sure to use the parts listed in the
service parts list of the applicable model and use the
proper tools.
(Failure to heed this warning may result in
electric shock, fire and/or injury.)
Caution against
electric shock
Prohibited
Turn off the power supply
Be sure to shut off the power supply isolator before dis-
assembling the unit for repair.
(Failure to heed this warning may result
in electric shock.)
Be sure to follow
this instruction.
Be sure to follow
this instruction.
Be sure to follow
this instruction.
Read the following precautions thoroughly before the maintenance, and then inspect and repair the product in a
safe manner.
The types and levels of danger that may arise if the product is handled incorrectly are described with the warning
symbols shown below.
Toxic gas generation
• Be careful that the coolant (R407C, R410A) does
not leak in a flammable environment.
• Conduct welding operation in an open room.
• If the coolant gas leaks, open the windows while
servicing.
• Be sure to completely repair the leak. Close the
service valve if the repair work is temporarily sus-
pended.
( If the coolant gas comes into contact
with flames such as open fire, sparks
and a heater, it may generate toxic gas. )
Be sure to follow
this instruction.
Prohibited
Proper electric work
Use the electric wires designated for electric work, and
conduct electric work in accordance with the "Electric
Installation Engineering Standard", the "Indoor Wiring
Regulations", and the Installation Instructions.
(Improper connection or wiring installation
may result in electric shock and/or fire.)
Be sure to follow
this instruction.
Replace damaged and/or degraded parts
Be sure to replace the power-supply cord and lead
wires if they are damaged and/or degraded.
(Failure to heed this warning may result in
electric shock and/or fire.)
Be sure to follow
this instruction.

─4 ─
Make sure that the product operates properly upon completing repair work. Clean the product and the surround-
ing area, and then notify the customer of the completion of repair.
Request for repair
Inspect the earth condition, and repair it if it is incomplete. Make sure that an earth leakage breaker or an
overload protection device is installed. If it is not installed, recommend the dealer to install one.
Caution Incorrect handling of the product may result in injury or
damage to properties including buildings and equipment.
Caution for injury
Do not work at a location where you do not have a
sure footing.
(Failure to heed this caution may result in
a fall.)
Wear gloves
Wear gloves when servicing.
(Failure to heed this caution may result in
injury to your hands from sharp metal or
other edges.)
Be sure to follow
this instruction.
Prohibited
Prevent water leakage
• Before removing any of the water-related parts,
completely drain the residual water from the piping.
• Upon completing repair work, be sure to check the
drainage of the indoor unit and that no water leaks
from any of the piping connections.
(Water leakage may cause buildings to
soil, leading to secondary failure of other
parts.)
Be sure to follow
this instruction.
2. Names and functions of components
Lossnay core
Temperature and humidity
are exchanged between
supply air and exhaust air.
High efficiency filters (Optional parts)
Removes dust from the outside air.
Damper plate
Switches between the Lossnay
ventilation and normal ventilation.
Air filter
Prevents clogs in the Lossnay core
*The illustration shows GUF-50RDH4.
Control box
Maintenance cover
Ceiling suspension fixture
Exhaust fan
Fan used to expel dirty air to outside of the room
Direct expansion coil
Heats or cools the air supply after heat exchange.
Electronic expansion valve
Maintenance cover (for humidifying)
Permeable-film humidifier
Performs clean humidifying of the air supply
after heat exchange.
Not available on GUF-50/100RD4types
Discharge valve
Drain discharge hole
Service valve
Strainer (O-ring installed)
Air supply fan
Fan to supply outside air to the inside
Water supply tube
Supplies water to the permeable-film humidifier.
Duct connection flange

─5 ─
3. Specifications
• The values given in the table for the noise level reflect the levels measured at a position 1.5 meters immediately
below the unit in an anechoic chamber.
• The noise at the air outlets (at a 45° angle, 1.5 meters in front) is about 5-6 dB (A) higher than the values given in
the table.
• The above values apply during Lossnay ventilation when the fan speed is set to high speed.
* Capability in ( ) is heat recovery capability by the Lossnay cores.
Cooling/Heating capability indicates the maximum value at operation under the following condition.
Cooling: Indoor: 27°C DB/19°C WB Outdoor: 35°C DB/24°C WB
Heating: Indoor: 20°C DB/13.8°C WB Outdoor: 7°C DB/6°C WB
• Mitsubishi Electric measures products according to Japan Industrial Standard (JIS B 8628).
• In the United Kingdom, on-site measurements by pitot tube method could be as much 20% different from JIS test
room conditions. If the measuring point is close to sources of turbulence like bends, contractions and dampers,
etc., it is difficult to measure the air volume correctly. A straight duct length more than 10D (D=duct diameter) from
the source of turbulence is recommended for correct measurement. On-site measurement should therefore be
carried out in accordance with BSRIA guideline (Commissioning Air Systems. Application procedures for buildings
AG3/89.3 (2001)).
Model name
Power
supply
(V)
Frequency
(Hz)
Current
(A)
Power con-
sumption
(W)
Air volume
External air load heat
processing capability (kw)
Humidifying
volume
Noise
(dB)
Weight
(kg)
Equivalent
indoor unit
capability
m3/h L/S Cooling
capability
Heating
capability
GUF-50RD4
Single-
phase
220-240
50
1.15 235-265 500 139 5.57
(1.94)
6.21
(2.04) -
33.5-34.5 54 P32
GUF-50RDH41.15 235-265 500 139 5.57
(1.94)
6.21
(2.04) 2.70
33.5-34.5 57 P32
GUF-100RD42.20 480-505
1,000 278 11.44
(4.12)
12.56
(4.26) - 38-39 92 P63
GUF-100RDH42.20 480-505
1,000 278 11.44
(4.12)
12.56
(4.26) 5.40 38-39 98 P63
GUF-100RDH4-60
Single-
phase
220
60 3.20 685 1,000 278 11.44
(4.12)
12.56
(4.26) 5.40 40.5 98 P63

─6 ─
4. Outside dimensions
GUF-50RD4, GUF-50RDH4, GUF-100RD4, GUF-100RDH4, GUF-100RDH4-60
G
P
M
L
20
100
øH
øJ
C
(N)
A
FE
N
D
B
79 79
N
T
150 to 250
60
Q
79
R
30
K
Air exhaust fan
Damper plate
Air supply fan
Ceiling suspension fixture
(4×13×30 length hole for GUF-50 types)
(4×15×30 length hole for GUF-100 types)
RA
(Return air)
Control box
Maintenance cover
EA
(Exhaust air)
Gas pipe
Drain discharge hole
(VP25 connection)
Lossnay core
Liquid pipe
Heat exchanger
Air filters
SA
(Supply air)
OA
(Outdoor air)
Ceiling suspension fixture
Maintenance cover
Location at which the duct direction can be changed
Lossnay core
Air filter
High efficiency filter
Fan
Maintenance space
Inspection
opening
Inspection
opening
Solenoid valve unit with
pressure regulator*
Solenoid valve
Heat exchange unit
Humidifying element
Maintenance space
Power cable
installation port
Upper location at which the ceiling
suspension fixture can be installed
(for GUF-100 types)
Location at which the duct direction
can be changed
Humidifying element*
S (Water intake)
(Discharge hole)
Water intake strainer
with check valve*
(PT1/2 External thread)
More than 600
(The components marked with * are available for GUF-50/100RDH4types only)
High efficiency filter
(Optional part)
Model
External
dimension
Ceiling suspen-
sion fixture pitch
Duct connection flange Duct pitch Humidification
Inspection
opening
Weight
(kg)
ABCDEF
Nominal
diameter
GH J K LMNPQRS T
GUF-50RD4
1288 1016 317 1185 1048 22 200 158.5 192 208 745 372.5 435 124 347 135 99 266 450 54
GUF-50RDH457
GUF-100RD4
1580 1231 398 1465 1271 16 250 199 242 258 920 460 670 149 361 169 110 280 600
92
GUF-100RDH4
GUF-100RDH4-60 98
Unit (mm)

─7 ─
5. Electrical wiring diagrams
GUF-50RD4, GUF-100RD4

─8 ─
GUF-50RDH4, GUF-100RDH4, GUF-100RDH4-60
AB
AB
GUF-50RDH4, GUF-100RDH4220-240 V 50
GUF-100RDH4-60 220 V 60

─9 ─
6. Circuit board diagrams
Circuit board diagrams and check points <FU-M05-D4>
1GUF-50RD4, GUF-50RDH4, GUF-100RD4, GUF-100RDH4
LEV
Power supply
220-240 V AC 50 Hz
14 V DC
12 V DC
5 V DC
GND
External humidifier
control input
Operation monitor output
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GXULQJRSHUDWLRQ
MA remote controller
transmission cable
M-NET
transmission cable
M-NET
transmission cable
6KLHOGHGSDUW
Error monitor output
QRUPDOO\

when there is an error 
Supply fan
&RPPRQ
Fuse
$9 7UDQVIRUPHUSULPDU\LQSXW
7UDQVIRUPHUVHFRQGDU\RXWSXW
16 to 23 V AC
KLJK
low
OA thermistor
Damper motor
220-240 V AC 50 Hz
Limit switch
RA thermistor
Gas pipe thermistor
Water sensor
Liquid pipe thermistor
LED3
On when M-NET line
power is on.
LED1
On when power is on.
Exhaust fan
&RPPRQ
Supply fan
220-240 V AC
50 Hz
KLJK
low
Exhaust fan
220-240 V AC
50 Hz
Solenoid value
Full-wave rectified YROWDJH
of 220-240 V AC 50 Hz
(GUF-50/100RDH4W\SHV
LED2
On when MA remote
controller power is on.
Address switch
7HQVGLJLW
Address switch
2QHVGLJLW
Branch No. switch
Function switch 3
Function switch 2
Function switch 1

─10 ─
2GUF-100RDH4-60
LEV
14 V DC
12 V DC
5 V DC
GND
External humidifier
control input
MA remote controller
transmission cable
M-NET
transmission cable
M-NET
transmission cable
(Shielded part)
Supply fan
(Common)
Fuse
(6.3 A/250 V)
OA thermistor
Limit switch
RA thermistor
Gas pipe thermistor
Water sensor
Liquid pipe thermistor
LED3
On when M-NET line
power is on.
LED1
On when power is on.
Exhaust fan
(Common)
LED2
On when MA remote
controller power is on.
Address switch
(Tens digit)
Address switch
(Ones digit)
Branch No. switch
Operation monitor output
ZKHQVWRSSHG
GXULQJRSHUDWLRQ
Error monitor output
QRUPDOO\

when there is an error )
Function switch 3
Function switch 2
Function switch 1
high
low
high
low
Transformer primary (input)
Transformer secondary (output)
16 to 23 V AC
Power supply
220 V AC 60 Hz
Damper motor
220 V AC 60 Hz
Supply fan
220 V AC
60 Hz
Exhaust fan
220 V AC
60 Hz
Solenoid value
Full-wave rectified voltage
of 220 V AC 60 Hz