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TOP---UPS OF UP TO 20---30% OF THE TOTAL AMOUNT OF
OIL CONTAINED IN THE COMPRESSOR CRANKCASE ARE
PERMITTED; FOR LARGER PERCENTAGES CONTACT THE
TECHNICAL SUPPORT DEPARTMENT.
5.2.1 -- Procedure for oil topping -- up
If there has been any loss of oil then this must be topped up as
follows:
1) Take a clean, dry, transparent container (with volume cal-
ibrations) and fill it with at least twice the amount of oil re-
quired.
2) Isolate the compressor by closing the cock on the liquid line.
6 --- Safety Devices Settings
The water chiller has already been tested and set up by the manufacturer. The following setting values are suggested in the field.
COMPONENT
Low pressure switch (LP)
High pressure switch (HP)
The settings for the safety valves installed on the machine are indicated below:
MODELS
CBH/CLH/CQH 017---020---023---025---028
SBH/SLH 017---020---023---025---028
SQH 017---020---023---025
6.1 --- Setting thermostatic expansion
valve
THIS OPERATION MUST BE PERFORMED BY AN EXPERI-
ENCED REFRIGERATION TECHNICIAN.
Before beginning this adjustment be sure that the refrigerant
charge is correct, checking the the sub ---cooling (3ûC --- 5ûC, as
specified in par. 5.1).
The valve has already been factory ---set and should be reset
when the superheating is not between 5ûC --- 8ûC, as follows:
1) Important:
Ensure that the instructions in par. 5.1 have been carried out.
2) Allow the compressor to operate for 15 mins.
3) Measure the superheating as follows:
a) Connect a manometer to the Schraeder connection lo-
cated on the evaporator outlet tube, and read the mano-
metric temperature on the scale for the refrigerant used
(for the units with R407C refer to the pressure gauge
scale indicated with the initials D.P . = Dew Point).
b) Using a contact thermometer, measure the temperature
on the tube coming out of the evaporator, next to the
socket used for the manometer.
c) The superheating is the difference between the two
readings (b ---a).
4) The superheating must be 5ûC --- 8ûC; if not, set the expan-
sion valve as follows:
3) Connect to the fittings on the compressor body (Schraeder
4) Using a pipe, connect the oil container to the oil service fitting
5) Open the oil service cock, lifting the container, so that the oil
6) Charge the required quantity of oil (make sure the tube al-
7) Stop the oil flow by closing the oil service fitting, open the
SETTING
Operation with R407C/R22
(standard factory setting):
START
: 3.6 bar
DIFF.
: 0.8 bar
STOP
: 2.8 bar
Operation with R407C/R22
(standard factory setting):
STOP
: 26 bar
START
: 20 bar
DIFF.
: 6 bar (fixed)
SETTINGS
29 bar
N.B:
If the superheating is too low, there is a risk of poor lubrication
and consequent breakage of the compressor as a result of pres-
sure shock.
If the superheating is too high the output of the system is limited
and the compressor overheats.
6
valves) and empty it of refrigerant until atmospheric pres-
sure (1 bar) is reached.
on the lower part of the compressor.
flows by gravity.
ways remains below the oil level in the container).
shut---off cock on the refrigerating circuit and restore the
drained refrigerant charge.
reset
a) Remove the protective cover;
b) Turn the adjustment screw to return to the optimum val-
ues, tightening it in a clockwise direction to increase the
superheating, or slackening it to reduce the superheat-
ing.
c) Wait about 10 minutes;
d) Measure the superheating and repeat the operation if
necessary.
NOTES
set
diff.
0.2 1.5
0.5
5
bar
bar
SAFETY VALVE
high pressure side
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