Mitsubishi Electric PAC-MK50BC User manual

No. OCH574
September 2014
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
TECHNICAL & SERVICE MANUAL
CONTENTS
1. SAFETY PRECAUTION ······································· 2
2. OVERVIEW OF UNIT ··········································· 5
3. SPECIFICATIONS ················································ 8
4. OUTLINES AND DIMENSIONS ··························· 9
5. WIRING DIAGRAM ············································· 10
6 . NECESSARY CONDITIONS FOR SYSTEM CONSTRUCTION·············· 11
7. TROUBLESHOOTING ········································ 15
8. DISASSEMBLY PROCEDURE ··························· 24
BRANCH BOX
HFC
utilized
R410A
Note:
•Thisservicemanual
describestechnicaldataof
branchbox.Asforindoor
unitsandoutdoorunit,
refertoitsservicemanual.
PARTS CATALOG (OCB574)
[Service Ref.]
PAC-MK50BC
PAC-MK30BC
[Model Name]
<Branch box>
PAC-MK50BC
PAC-MK30BC
(IndispensableoptionalpartsforPUMY-P112/125/140VKM1andPUMY-P112/125/140YKM1)

2
1SAFETY PRECAUTION
Cautions for units utilizing refrigerant R410A
1-1. ALWAYS OBSERVE FOR SAFETY
Use new refrigerant pipes.
Charge refrigerant from liquid phase of gas
cylinder.
If the refrigerant is charged from gas phase, composition
change may occur in refrigerant and the efficiency will be
lowered.
Do not use refrigerant other than R410A.
If other refrigerant (R22, etc.) is used, chlorine in refrige-
rant can cause deterioration of refrigerant oil, etc.
Use a vacuum pump with a reverse flow check
valve.
Vacuum pump oil may flow back into refrigerant cycle and
that can cause deterioration of refrigerant oil, etc.
Use the following tools specifically designed for
use with R410A refrigerant.
The following tools are necessary to use R410A refrigerant.
Handle tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Do not use a charging cylinder.
If a charging cylinder is used, the composition of refrigera-
nt will change and the efficiency will be lowered.
Flare tool
Electronic refrigerant
charging scale
Vacuum pump adaptor
Size adjustment gauge
Gauge manifold
Torque wrench
Gas leak detector
Charge hose
Tools for R410A
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant, oil etc.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
If large amount of mineral oil enters, that can cause deterio-
ration of refrigerant, oil etc.
Store the piping indoors, and both ends of the
piping sealed until just before brazing.
(Leave elbow joints, etc. in their packaging.)
Make sure that the inside and outside of refrige-
rant piping is clean and it has no contaminants
such as sulfur, oxides, dirt, shaving particles, etc,
which are hazard to refrigerant cycle.
In addition, use pipes with specified thickness.
The refrigerant oil applied to flare and flange
connections must be ester oil, ether oil or
alkylbenzene oil in a smalll amount.
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the
unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the
spec labels provided with our products.
We will not be held responsible for mechanical failure,
system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.
Use the specified refrigerant only. Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
1-2. CAUTIONS RELATED TO NEW REFRIGERANT
Before obtaining access to terminal, all supply
circuit must be disconnected.
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3
Gravimeter
Unit
[3] Service tools
(1) Use the below service tools as exclusive tools for R410A refrigerant.
[2] Additional refrigerant charge
When charging directly from cylinder
·CheckthatcylinderforR410Aonthemarketisasyphontype.
·Chargingshouldbeperformedwiththecylinderofsyphonstoodvertically.(Refrigerantischargedfromliquidphase.)
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
No. Toolname Specifications
1Gaugemanifold
·OnlyforR410A
·Usetheexistingfittingspecifications.(UNF1/2)
·Usehigh-tensionsidepressureof5.3MPa·Gorover.
2Chargehose ·OnlyforR410A
·Usepressureperformanceof5.09MPa·Gorover.
3Electronicscale
4Gasleakdetector ·UsethedetectorforR134a,R407CorR410A.
5Adaptorforreverseflowcheck ·Attachonvacuumpump.
6Refrigerantchargebase
7Refrigerantcylinder ·OnlyforR410A·Topofcylinder(Pink)
·Cylinderwithsyphon
8Refrigerantrecoveryequipment
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4
(2) Cautions for refrigerant piping work
NewrefrigerantR410Aisadoptedforreplacementinverterseries.AlthoughtherefrigerantpipingworkforR410Aissame
asforR22,exclusivetoolsarenecessarysoasnottomixwithdifferentkindofrefrigerant.Furthermoreastheworking
pressureofR410Ais1.6timeshigherthanthatofR22,theirsizesofflaredsectionsandflarenutsaredifferent.
1Thicknessofpipes
BecausetheworkingpressureofR410AishighercomparedtoR22,besuretouserefrigerantpipingwiththickness
shownbelow.(Neverusepipesof0.7mmorbelow.)
2Dimensionsofflarecuttingandflarenut
ThecomponentmoleculesinHFCrefrigerantaresmallercomparedtoconventionalrefrigerants.Inadditiontothat,
R410Aisarefrigerant,whichhashigherriskofleakagebecauseofitsworkingpressurehigherthanthatofotherrefriger-
ants.Therefore,toenhanceairtightnessandstrength,flarecuttingdimensionofcopperpipeforR410Ahasbeenspeci-
fiedseparatelyfromthedimensionsforotherrefrigerantsasshownbelow.ThedimensionBofflarenutforR410Aalso
haspartlybeenchangedtoincreasestrengthasshownbelow.Setcopperpipecorrectlyreferringtocopperpipeflaring
dimensionsforR410Abelow.For1/2”and5/8”inchpipes,thedimensionBchanges.
Usetorquewrenchcorrespondingtoeachdimension.
3ToolsforR410A(Thefollowingtableshowswhetherconventionaltoolscanbeusedornot.)
1/4
3/8
1/2
5/8
3/4
6.35
9.52
12.70
15.88
19.05
0.8
0.8
0.8
1.0
—
0.8
0.8
0.8
1.0
1.0
Nominal
dimensions (in)
Diagram below: Piping diameter and thickness
Outside
diameter (mm)
Thickness (mm)
R410A R22
1/4
3/8
1/2
5/8
3/4
6.35
9.52
12.70
15.88
19.05
9.1
13.2
16.6
19.7
—
9.0
13.0
16.2
19.4
23.3
Nominal
dimensions (in)
Flare cutting dimensions
Outside
diameter (mm)
Dimension A ( )
+0
-0.4 (mm)
R410A R22
1/4
3/8
1/2
5/8
3/4
6.35
9.52
12.70
15.88
19.05
17.0
22.0
26.0
29.0
—
17.0
22.0
24.0
27.0
36.0
Nominal
dimensions (in)
Flare nut dimensions
Outside
diameter (mm
)
Dimension B (mm)
R410A R22
Gauge manifold
Charge hose
Gas leak detector
Refrigerant recovery equipment
Refrigerant cylinder
Applied oil
Safety charger
Charge valve
Vacuum pump
Flare tool
Bender
Pipe cutter
Welder and nitrogen gas cylinder
Refrigerant charging scale
Vacuum gauge or thermis-
tor vacuum gauge and
vacuum valve
Charging cylinder
Air purge, refrigerant charge
and operation check
Gas leak check
Refrigerant recovery
Refrigerant charge
Apply to flared section
Prevent compressor malfunction
when charging refrigerant by
spraying liquid refrigerant
Prevent gas from blowing out
when detaching charge hose
Vacuum drying and air
purge
Flaring work of piping
Bend the pipes
Cut the pipes
Weld the pipes
Refrigerant charge
Check the degree of vacuum. (Vacuum
valve prevents back flow of oil and refri-
gerant to thermistor vacuum gauge)
Refrigerant charge
Tool exclusive for R410A
Tool exclusive for R410A
Tool for HFC refrigerant
Tool exclusive for R410A
Tool exclusive for R410A
Ester oil and alkylbenzene
oil (minimum amount)
Tool exclusive for R410A
Tool exclusive for R410A
Tools for other refrigerants can
be used if equipped with adop-
ter for reverse flow check
Tools for other refrigerants
can be used by adjusting
flaring dimension
Tools for other refrigerants can be used
Tools for other refrigerants can be used
Tools for other refrigerants can be used
Tools for other refrigerants can be used
Tools for other refrigerants
can be used
Tool exclusive for R410A
Tools and materials Use R410A tools Can R22 tools be used?
(Usable if equipped
with adopter for rever-
se flow)
(Usable by adjusting
flaring dimension)
Can R407C tools be used?
Ester oil:
Alkylbenzene oil: minimum amount
(Usable if equipped
with adopter for rever-
se flow)
(Usable by adjusting
flaring dimension)
: Prepare a new tool. (Use the new tool as the tool exclusive for R410A.)
: Tools for other refrigerants can be used under certain conditions.
: Tools for other refrigerants can be used.
DimensionA
DimensionB
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2OVERVIEW OF UNIT
Indoor unit (Ceiling concealed type)
Indoor unit
(Wall mounted type)
Outdoor unit Branch Box
2-1. SYSTEM OUTLINE
TheadditionalconnectionoftheBranchBoxtogetherwithemploymentofthecompacttrunk-lookingoutdoorunitcan
successfullyrealizesalongdistancepipingforbighouses.Equippedwithamicroprocessor,theBranchBoxcantrans-
latethetransmissionsignalofindoorunitstoachievetheoptimumcontrol.
2-1-1. System example
2-1-2. Method for identifying
■ Outdoor unit
PU M Y - P 125 Y K M 1 - BS
Refrigerant
R410A
Indicates equivalent
to Cooling capacity
Power supply
V: Single phase
220/230/240 V, 50 Hz
Y: 3-phase
380/400/415 V, 50 Hz
Outdoor unit
model type
M-NET control
Frequency
conversion
controller
Outdoor unit
MULTI-S
(k cal/ h)
Salt proof
type
Sub number
Branch box (Controller)
Number of branches
5 : 5 branches
3 : 3 branches
Model type
Symbol of factory
P A C – MK 5 0 BC
(Indispensable)
Optional parts
■ Branch box
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