3 Installation
Installation manual
6
08CA
ROTEX HPU hybrid outdoor unit
4P344907-1C – 2016.02
3.2.4
To prevent the outdoor unit from falling
over
1
Prepare 2 cables as indicated in the following illustration (field
supply).
2
Place the 2 cables over the outdoor unit.
3
Insert a rubber sheet between the cables and the outdoor unit
to prevent the cable from scratching the paint (field supply).
4
Attach the cable’s ends. Tighten those ends.
3.3
Connecting the refrigerant piping
DANGER: RISK OF BURNING
3.3.1
To connect the refrigerant piping to the
outdoor unit
1
Connect the liquid refrigerant connection from the indoor unit to
the liquid stop valve of the outdoor unit.
a
b
c
a
Liquid stop valve
b
Gas stop valve
c
Service port
2
Connect the gas refrigerant connection from the indoor unit to
the refrigerant stop valve of the outdoor unit.
3.4
Checking the refrigerant piping
3.4.1
To check for leaks
NOTICE
Do NOT exceed the unit's maximum working pressure (see
"PS High" on the unit name plate).
NOTICE
Make sure to use a recommended bubble test solution
from your wholesaler. Do not use soap water, which may
cause cracking of flare nuts (soap water may contain salt,
which absorbs moisture that will freeze when the piping
gets cold), and/or lead to corrosion of flared joints (soap
water may contain ammonia which causes a corrosive
effect between the brass flare nut and the copper flare).
1
Charge the system with nitrogen gas up to a gauge pressure of
at least 200 kPa (2 bar). It is recommended to pressurize to
3000 kPa (30 bar) in order to detect small leaks.
2
Check for leaks by applying the bubble test solution to all
connections.
3
Discharge all nitrogen gas.
3.4.2
To perform vacuum drying
1
Vacuum the system until the pressure on the manifold indicates
−0.1 MPa (−1 bar).
2
Leave as is for 4-5 minutes and check the pressure:
If the pressure…
Then…
Does not change
There is no moisture in the
system. This procedure is
finished.
Increases
There is moisture in the
system. Go to the next step.
3
Evacuate for at least 2 hours to a pressure on the manifold of
−0.1 MPa (−1 bar).
4
After turning OFF the pump, check the pressure for at least
1 hour.
5
If you do NOT reach the target vacuum or cannot maintain the
vacuum for 1 hour, do the following:
▪ Check for leaks again.
▪ Perform vacuum drying again.
NOTICE
Be sure to open the gas stop valve after piping installation
and vacuuming. Running the system with the valve closed,
the compressor may break down.
3.5
Charging refrigerant
3.5.1
To determine the additional refrigerant
amount
If the total liquid
piping length is…
Then…
≤10 m
Do NOT add additional refrigerant.
>10 m
R=(total length (m) of liquid
piping–10 m)×0.020
R=Additional charge (kg)(rounded in units
of 0.1 kg)
