J&E Hall V3 FUSION, Техническое руководство

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Issue: 01.06.2023 Page 8
Adjustment on DNS-D306
•
High Pressure Cut Out: Turning the adjusting screw (8)
clockwise to increase the cut-out pressure setting and
vice versa. Lock the spindle with locking plate after
setting.
•
Low Pressure Cut in : Turning the range adjusting screw
(2) clockwise to decrease the cut-in pressure setting
and vice versa.
•
Low Pressure Differential : Turning the differential
adjusting screw (3) clockwise to increase the
differential pressure setting and vice versa. Lock the
spindle with locking plate after setting.
Figure 7: Adjustment on Danfoss KP17WB
KP17WB has high pressure convertible reset feature. Insert
screwdriver into the slot on the lock disc and turn it to the
desired reset configuration as shown in
Figure 8.
Do not turn the screw on the lock disc as it may damage the
convertible reset mechanism.
Figure 8:
KP17WB:
high pressure reset option
When high pressure trip is changed to auto reset on
KP17WB, the compressor is ready to turn ON when
discharge pressure drops below the setting value of (Cut
Out
– Fixed Differential).
When HP switch cut out mode is changed
from Manual to Auto operation, the fitting of
an ART (anti-recycle timer) is recommended
to protect the compressor.
Table 4: Dual Pressure Switch Manufacturer Setting
Series Model
High (barg) Low (barg)
Cut
Out
Diff.
(Fixed)
Cut
In
Diff (adj)
1,2 DNS-D306 20 7 3 2
3,4,6 KP17WB 18 4 3 2
Pressure switch settings
Both the LP and HP switch settings must be adjusted to
suit application before starting the unit.
Ensure that the
high-pressure setting does not exceed the value shown in
Table 5.
High pressure safety
•
The high-pressure safety switch is required to stop the
compressor should the discharge pressure exceed the
compressor’s high side operating pressure.
•
The high-pressure switch can be set to lower values
depending on the application and ambient conditions.
Low pressure protection
•
The low-pressure protection cut out switch protects the
compressor against deep vacuum operation, a
potential cause of failure due to internal arcing and
operating outside the compressor limits.
•
The low-pressure protection cut out should never be set
lower than the min. LP cut out value in
Table 5 . For
systems without pump-down integrated, the LP switch
signal contact shall be used to energize a low-pressure
safety alarm.
•
If a thermostat is used for room temperature control,
and a pump down feature is not integrated, a low-
pressure control of the manual reset type should be
wired in series with the thermostat to serve as a
protection cut-off in the event of loss of refrigerant
charge or other abnormal conditions which resulting in
low suction pressures.
•
When used for low temperature operational control,
the low-pressure control should be provided with a low
differential for accurate control. For accuracy,
refrigeration gauges must be used in setting cut-in and
cut-out points, since the indicator on the face of the
pressure switch is not sufficiently accurate for control
purposes.
•
Compressor operating pressures should be kept within
the limits in
Table 5 .
Table 5: Compressor operating pressures in barg
Series 1,2 2,3,4,6 1,2 2,3,4
Application M* L*
Compressor
Family
AE/AJ ZB AJ/FH ZF/ZFI
Refrigerant R407A R407A R134a R448A R407A
R407F R407F R449A R407F
R448A R448A R452A R448A
R449A R449A R449A
R452A R452A
Min. LP Cut
Out
1.5 2 0.6 0.1 0.3
Max. HP
Cut Out
27.7 18 27.7
LP Range 1.5~8.3 2.0~7.1 0.6~3.8 0.1~3.3
HP Range 13.2~27.7 6.6~15.8 13.2~27.7
*M: Medium Temperature; L: Low Temperature