15
Contractor’s manual
F15 - F30 Generators
Manual For F15 and F30 - Mill.: 2008 - 11 / Mod. : JPM 05
Page
3
4
2
1
7.4 Connections to the refrigerating
circuit
7.4.1 General topics concerning the liquid and
suction
pipes
Important
Every precaution must be taken to ensure that the
refrigerant piping is clean and free from moisture
and enhances oil return to the compressor.
Concerning the suction pipe, as far as possible the loss of
pressure between the generator and the compressor must
not exceed a value corresponding to a variation of about
1 to 2°C in the temperature of the saturated fl uid.
7.4.2 Generator and refrigerating system
located at the same level
F15 and F30 generators are fi tted with a thermostatic ex-
pansion valve. A heat exchanger is supplied not mounted
with the generator. Install it according to the diagram
below, horizontally and close to the generator.
The diameters of pipes «section 7» can be retained for a
maximum developed length of 6 m.
7.4.3 Generator and refrigerant systems
located at different levels
In the case where the compressor and the generator are
mounted at different levels, certain precautions concerning
the piping must be taken into account.
7.4.3.1 Suction pipe
The suction pipe must be arranged with a slope descend-
ing towards the compressor and any part of the piping that
could constitute a fl uid trap must be avoided.
Wherever the suction piping has to rise, a siphon must be
provided to form an oil trap at the output from the evapora-
tor. It is advisable to install a double siphon three metres
from the rising piping.
Regarding the section of suction piping sloping towards
the compressor, a reverse siphon must be placed at the
top in order to prevent any return behind of oil.
Where the suction piping is very long, it is recommended,
after a section of ascending piping of suffi cient size to en-
sure the correct oil carry-over, that a change is made to a
larger cross section in order to minimise pressure drop.
The suction piping must be thermally insulated in accord-
ance with current technology.
The thermal insulation must have a thickness of at least 13
mm and must tight to vapour migration (this is to prevent
rotting of the insulating material).
7.4.3.2 Liquid pipe
Any gas trap must be avoided, that is any section of pip-
ing in an inverted «U» so as not to interrupt the fl ow of
liquid.
A solenoid valve on the liquid line must shut off the supply
of refrigerant fl uid from the generator in order to avoid any
risk of liquid fl uid fl owing into the compressor.
Where the difference in level is greater than about 5 m, it
is recommended that the liquid pipe is increased in size.
In this case, it is possible that the selection of the expan-
sion valve may have to be reconsidered, no longer taking
into account the condensation pressure but the pressure
existing upstream of the expansion valve.
Connections to the refrigerating circuit
Refer to the section «Safety Concerning Pressu-
rised Equipment».
4 m/s or more
4 m/s or more
8 to 12 m/s
Max
3 m
Max
3 m
10 hour
bulb
Suction
HP Fluid
Insulation
0,5 %
0,5 %
–
Supplied with the
generator
- - -
To be fitted on site
1
Thermostatic
expansion valve
3
Evaporating pressure
regulator
(if required)
2
Heat exchanger
F15 - 7/8 - 3/8
F30 - 1"1/8 - ½
4
Liquid solenoide valve
