Mitsubishi Electric EHST20C-VM6HB Service Manual page 6

3-3. PRECAUTIONS WHEN REUSING EXISTING R22 REFRIGERANT PIPES
Flowchart
• Refer to the flowchart below to determine if the existing pipes can be used and if it is necessary to use a filter dryer.
• If the diameter of the existing pipes is different from the specified diameter, refer to technological data materials to confirm if the pipes can be used.
The existing pipe thickness meets specifica-
tions and the pipes are not damaged.
Check if the existing outdoor unit can operate.
After operating the cooling system for about 30
minutes, do a pump down work.
Disconnect the existing outdoor unit from the
pipes.
Attach the new outdoor unit
Perform the airtight test, vacuum air purging,
additional refrigerant charging (if necessary),
and gas leak check.
3-4. PRECAUTIONS FOR SALT PROOF TYPE "-BS" MODEL
Although "-BS" model has been designed to be resistant to salt damage, observe the following precautions to maintain the per-
formance of the unit.
1. Avoid installing the unit in a location where it will be exposed directly to seawater or sea breeze.
2. If the cover panel may become covered with salt, be sure to install the unit in a location where the salt will be washed away
by rainwater. (If a sunshade is installed, rainwater may not clean the panel.)
3. To ensure that water does not collect in the base of the outdoor unit, make sure that the base is level, not at angle. Water
collecting in the base of the outdoor unit could cause rust.
4. If the unit is installed in a coastal area, clean the unit with water regularly to remove any salt build-up.
5. If the unit is damaged during installation or maintenance, be sure to repair it.
6. Be sure to check the condition of the unit regularly.
7. Be sure to install the unit in a location with good drainage.
OCH533D
Measure the existing pipe thickness and
check for damage.
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• If the existing outdoor unit cannot operate, use
a refrigerant recovery device to collect the refrigerant.
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Use new pipes for SW75, SW100 and SW120 models.
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The existing pipe thickness does not meet
specifications or the pipes are damaged.
The existing pipes cannot be reused.
Use new pipes.
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