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User Guide | Optyma™ iCO2
28 | BC408445719305en-000101
© Danfoss | Climate Solutions | 2023.01 | LCA012A030
(3)Prevention of short cycle operation
Short cycle operations (frequent repetitions of start and stop) could cause a short supply of
lubrication oil as a result of excessive oil rise at the time of starting. In addition, if a large start current
flows repeatedly through the built-in motor, the motor may overheat, resulting in motor coil burnout.
To prevent the short cycle operation, it is necessary at the minimum to set such that the pattern as
shown at right will be achieved. Major causes of short cycle operation are as follows
• Unbalanced load and condensing unit capacity
• Clogged suction strainer
• Improper setting of the operating pressure value
In addition to the above, where a unit cooler is used, the temperature sensor of inside compartment
temperature regulator may be misplaced (the temperature sensor is blown directly by cold air from
the unit cooler). Adjust the inlet suction superheating degree of condensing unit at 5 – 40 deg.
Operation
Inside compartment temperature
Room temperature
(
)
Stop
3 min.
or more
4 min.
or more
7 min.
or more
Time
(4) Standard operational data
The figures in the table below are reference values; with change in outside ambient temperatures and/or evaporation temperatures, the operating
conditions will be different from the table below.
Standard data - OP-UPAC015COP04E
Outside
temperature
(˚C)
Evaporation
temperature
(˚C)
Compressor
Rotating rate
(rps)
HP/MP/LP
(bar g)
Td
(˚C)
EEVG
(pulse)
EEVSC
(pulse)
EEVLB
(pulse)
Rated refrigeration
value
32
-10
103
91.5/50.2/26.0
82.5
399
435
0
Rated freezing value
32
-40
102
83.7/29.5/9.0
125
181
86
313
Outside
temperature
(˚C)
Evaporation
temperature
(˚C)
Compressor
Rotating rate
(rps)
HP/MP/LP
(bar g)
Td
(˚C)
EEVG
(pulse)
EEVSC
(pulse)
EEVLB
(pulse)
Refrigeration
overload
42
-10
102
110/58.5/25.8
104.3
399
395
0
Freezing overload
42
-40
100
105/36.5/9.1
130.7
180
80
311
Outside
temperature
(˚C)
Evaporation
temperature
(˚C)
Compressor
Rotating rate
(rps)
HP/MP/LP
(bar g)
Td
(˚C)
EEVG
(pulse)
EEVSC
(pulse)
EEVLB
(pulse)
Refrigeration low
outside temperature
3.2
-10
102
84.9/48.7/26.3
87.9
400
334
0
Freezing low outside
temperature
-5.4
-40
104
86.8/41.3/8.0
109
400
83
0
(2) Prevention of reverse phase operation
Compressor of this equipment runs in one direction only. If it is run in reverse direction, the compressor may fail to operate properly.
To prevent the reverse phase operation, the unit is equipped with the reverse phase prevention relay which checks whether the phase of power supply
is positive or reverse and, if it is in the reverse phase, displays the error code “E32”, inhibiting the compressor start.
In such occasion, check that the primary (power supply side) phase and secondary phase are the same phase.
L1 L2 L3 N
L1 L2 L3 N
Primary side
Secondary
Source power
Note:
Turn power off before replacing the connection for prevention of electric shock.