Mitsubishi Heavy Industries SRK20ZIX-S Service Manual page 33

5. UTILIZATION OF EXISTING PIPING.
Check whether an existing pipe system is reusable or not by using the following flow chart.
START
NO
Are an outdoor unit and an indoor unit connected to the
existing pipe system to reuse?
YES
NO
Are the existing units our products?
YES YES
Does the existing pipe system to reuse satisfy all of the following?
(1) The pipe length is 30m or less.
(2) The pipe size conforms to the table of pipe size restrictions.
(3) The elevation difference between the indoor and outdoor units
NO
conforms to the following restrictions.
Where the outdoor unit is above: 15m or less
Where the outdoor unit is below: 15m or less
YES
YES
Is the unit to install in the existing pipe system a
twin-triple-double-twin model?
NO
YES
Is the existing pipe system to reuse free of corrosion, flaws or dents?
NO
Is the existing pipe system to reuse free of gas leaks?
(Check whether refrigerant charge was required frequently for
the system before)
NO
Are there any branch pipes with no indoor unit connected?
NO
Are heat insulation materials of the existing pipe system to
reuse free of peel-offs or deterioration?
(Heat insulation is necessary for both gas and liquid pipes)
NO
Aren't there any loose pipe supports?
Some loose pipe supports
No loose pipe supports
The existing pipe system is not reusable.
The existing pipe system is reusable.
Install a new pipe system.
INSTALLATION TEST CHECK POINTS
Check the following points again after completion of the installation, and before turnig on the power. Conduct a test run again and ensure that the unit operates properly.
Explain to the customer how to use the unit and how to take care of the unit following the instruction manual.
After installation
Power cables and crossover wires are securely fixed to the terminal block.
The power supply voltage is correct as the rating.
The drain hose is fixed securely.
Operational valve is fully open.
No gas leaks from the joints of the operational valve.
X Y
Remote controller
Which of the following refrigeration oils
Can't
Please make an
does the existing unit use? NO Use
inquiry for
Suniso, MS, Barrel Freeze, HAB, Freol,
reusability.
ether oil, ester oil
Can Use
Check with the flow chart developed for a case where
an existing pipe system is reused for a
twin-triple-double-twin model published as a
technical data sheet.
Change is impossible.
Change the branching pipe to a specified type.
Change
Repair is impossible.
Repair the damaged parts.
Repair
Air tightness is
impossible.
Check the pipe system for air tightness on the site.
Air tightness is OK
Remove is
impossible
Remove those branches.
Remove
Repair is impossible.
Repair the damaged parts.
Repair
Repair the damaged parts.
Repair
The pipe joints for indoor and outdoor pipes have been insulated.
The reverse flow check cap is attached.
The cover of the pipe cover (A) faces downward to prevent rain from entering.
Gaps are properly sealed between the pipe covers (A) (B) and the wall surface / pipes.
three cables contained in a conduit and a voltage drop is 2%. For an installation falling outside of these
conditions, please follow the internal cabling regulations. Adapt it to the regulation in effect in each country.
<Table of pipe size restrictions>
Standard pipe size Usable Restricted to shorter pipe length limits
Additional charge volume per meter of pipe
Liquid pipe
Pipe size
Gas pipe
Usability
40 Maximum one-way pipe length
Length covered without additional charge
Usability
50 Maximum one-way pipe length
Length covered without additional charge
Usability
60 Maximum one-way pipe length
Length covered without additional charge
Please consult with our distributor in the area, if you need to recover refrigerant and charge it again.
Any combinations of pipe sizes not listed in the table are not usable.
Formula to calculate additional charge volume
Additional charge volume (kg) = {Main pipe length (m) – Length covered without additional charge shown in the table (m)}
Additional charge volume per meter of pipe shown in the table (kg/m)
If you obtain a negative figure as a result of calculation, no additional refrigerant needs to be charged.
Example) When an 60 is installed in a 10m long existing pipe system (liquid
the quantity of refrigerant to charge additionally should be (10m-5m) x 0.06kg/m = 0.3 kg.
WARNING <Where the existing unit can be run for a cooling operation.>
Carry out the following steps with the excising unit (in the order of (1), (2), (3) and (4))
(1) Run the unit for 30 minutes for a cooling operation.
(2) Stop the indoor fan and run the unit for 3 minutes for a cooling operation (returning liquid)
(3) Close the liquid side operation valve of the outdoor unit and pump down (refrigerant recovery)
(4) Blow with nitrogen gas. If discolored refrigeration oil or any foreign matters is discharged
by the blow, wash the pipe system or install a new pipe system.
For the flare nut, do not use the old one, but use the one supplied with the outdoor unit.
Process a flare to the dimensions specified for R410A.
<Where the existing unit cannot be run for a cooling operation.>
Wash the pipe system or install a new pipe system.
If you choose to wash the pipe system, please contact our distributor in the area.
9.52, gas 12.7),