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55908039-03
PIPE CONNECTIONS
Units are supplied with the following male flare connections (sizes in inches):
Model
MCU+
Size
50
80
90
100
130
150
165
180
Expansion
3/8 1/2 1/2 1/2 1/2 1/2 1/2 1/2
Suction
1/2 5/8 5/8 3/4 3/4 3/4 3/4 7/8*
CONNECTING THE UNITS
1.
Ensure both service valves on the unit are closed (clockwise) before
commencing installation.
2.
If a expansion assembly requires cleaning:
a. Remove the entire expansion assembly from the outdoor unit.
b. Split the expansion assembly in the middle and remove the existing
restrictor.
c.
Drop the new restrictor vertically into the field connector.
d. Reassemble in the vertical plane (field connector lowest) when
reassembled the restrictor can be heard to be free to move if the
assembly is shaken.
e. Refit the expansion assembly.
3.
Connecting the pipework
a. Remove the flare nuts from the suction service valve and the expansion
device as appropriate.
b. Ensure that both the suction and expansion lines are fully insulated.
c. Place the flare nuts over the incoming pipework and flare the pipe ends.
d. Connect the pipework between the units. Do not leave pipes ends, valves
etc open to the atmosphere. Always use 2 spanners when tightening the flare nuts to avoid
twisting the pipes. Use a small amount of refrigerant oil on the mating surfaces.
e. Sight glasses and filters driers are not necessary, but if required should be fitted between the out
door unit liquid shut off valve and the expansion device on the MCU+ units.
f.
MCU+ 180 has a
⅞¨ suction pipe with brazed connections. Use a protective shield to avoid
scorching the side panel.
EVACUATING
With the valves closed, connect a vacuum pump to the service ports on the outdoor unit valves. Evacuate the
interconnecting pipework and indoor unit to 1000 microns (1 Torr) or better. Allow this to be held for a minimum of 15
minutes
BRANCH LINE LENGTH
All branch lines must have the
same equivalent lengths
to ensure that the system is correctly balanced
.
MCU+ ELECTRICAL
•
The installer supplies mains, control and interconnecting cables: equipment must be earthed.
•
Wiring must be carried out in accordance with local and national codes.
•
Mains supply cables must be size compatible with the recommended fuse.
•
An all pole isolator switch should be positioned within easy reach of the indoor/outdoor unit dependant on
which receives the fuse supply.
•
Cable clamps for use with stranded cables are supplied and should be used to secure incoming/outgoing
cables. Installers must supply a method of securing solid sheathed cables.
3PH MCU+
On 3 PH MCU+ it is possible for the scroll compressor to run backwards.