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Refrigerant Pipework
This must be carried out before connection of any electrical and controls cables
and in accordance with the Instructions that come with the Mitsubishi Electric
City Multi equipment. This work must only be undertaken by a Mitsubishi Electric
approved Contractor.
Refrigerant installation pipework sizes need to be as follows :-
Air Curtain
Discharge Line
(Gas)
Liquid Line
Index Size
VRF PHV1000 DXE HO
8
5 in.
8
3 in.
P100
VRF PHV1500 DXE LO
8
5 in.
8
3 in.
P125
VRF PHV1500 DXE HO
8
5 in.
8
3 in.
P140
VRF PHV2000 DXE LO
8
5 in.
8
3 in.
P140
VRF PHV2000 DXE HO
4
3
in.
8
3 in.
P200
NOTE: Contact Mitsubishi Electric for recommended pipework lengths, numbers of fittings etc.
The installation must be done in accordance with Mitsubishi Electric Service Manual.
It is intended that refrigerant pipe connections to the air curtain are made using brazed
joints and these must be carried out in a professional and safe manner. If installation
pipe sizes for the discharge (gas) line and liquid line are different from the pipe
connection sizes on the air curtain, suitable pipe reducers must be used for the
connection. R410A refrigerant systems can operate at pressures up to 610 psi (c. 42
Bar). These brazed joints may well be located in a public area and a weakness leading
to an explosion could be extremely dangerous. The air curtain with its coil is
manufactured in accordance with the Pressure Equipment Directive and the installation
must be carried out to a good standard of workmanship. Remove the protective plastic
film on top of the air curtain before starting work. Use a heat sink on the copper pipes
when brazing to reduce the transfer of heat to the inside of the air curtain where
sensitive components are located. Make sure the thermistor (gas) sensor has not been
inserted into its pocket on the gas pipe at the top of the air curtain before brazing.
Remove it if it has or it will burn when the pipe connection is brazed.
For the City Multi system the LEV needs to be brazed into
the liquid line as close as possible to the air curtain (2m
maximum). The picture shows an example of this. On the
VRF PHV2000 DXE HO there are two LEVs to be fitted in
parallel (see Mitsubishi Electric AHU Controller
instructions). If required the LEV(s) can be hidden away in
an adjacent void or above ceiling tiles, or the LEV(s) and
pipework can be hidden inside the optional sheet metal
services covers, see Page 8.
For the City Multi VRF R2 and WR2 Series system, pipework from each air curtain must
connect to one pair of ports on the Mitsubishi Electric BC Controller. The exception to
this is the VRF PHV2000 DXE HO air curtain that requires 2 pairs of ports on the BC
Controller to achieve the correct output. Do not combine pipework from two or more air
curtains together into one set of pipework and then connect this to one pair of ports.
NB:
A maximum P140 Index is possible from 1 pair of ports, contact Mitsubishi Electric.
