McQuay MDS030AR Applications Manual page 69

Installation of the Combined Outdoor Units (Suitable for Model of MDS260/280/300)
Two outdoor units can be grouped as one outdoor unit, to connect with indoor units. The
installation of combined units is more complicated than that of the single outdoor unit; please
read the below notes carefully before installation, and strictly follow the installation
instructions.
Select the position of the installation for outdoor unit
Select one unit as the master unit, the other one as the slave unit; and these two units shall
be positioned in the same level side by side.
Master unit and slave unit shall be installed in the same level.
The distance between the master and slave unit shall be more than 10mm.
Connecting pipe of the outdoor units
Accessory copper parts are packed with the outdoor units; pipe connection includes
gas, liquid and balance piping connection between the master and slave units. All pipes
shall be with insulation material and avoid any damage of this insulation material.
Gas and liquid pipe connection
Gas and liquid pipe connection with the units, please refer to the concerned chapter of
installation of refrigeration pipe .
Gas and liquid pipe shall be connected paralleled, shown as below. The dimensions of
the straight pipe connected to the Tri-joint must meet the requirements below.
To units
Elbow
For 28.6mm gas pipe,
directly connect to Tri-joint;
For 34.9mm gas pipe, add a
reducer and a transition pipe
Design & installation Guide For McQuay MDS Multi System
A
To units
(Remove the panel before
connecting pipe)
Position to connect pipe position
Master and slave units must be
installed in the same level
A >10mm
B >200mm
C >500mm
D>100mm
Tri-joint
28.6mm a transiton pipe
(only for 34.9mm gas pipe)
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