SiBE811001EB
Outline of Functions (Outdoor unit)
CONVENI-PACK
104
&
&
&
&
&
OR
OR
&
&
&
Capacity control
Control by predicted HP
DC step of compressor
3 step down / 15 sec.
(To lowest step)
• When compressor is stopped
• When communication with outdoor unit is normal
• BU_MP < 1.568MPa continues for 3 consecutive min.
• When there is a communication error with outdoor unit
• Predicted booster HP < 1.274MPa continues for 3 consecutive min.
Maintenance of
freezing capacity
• When compressor is stopped
• When communication with outdoor unit is normal
• BU_MP > 1.764MPa
• When there is a communication error with outdoor unit
• Predicted booster HP > 1.568MPa
Freezing capacity control
• To obtain optimal cooling performance relative to the target evaporating temperature (Tst_Bu), compressor frequency is
increased or decreased according to low pressure. Target evaporating temperature (Tst_BU) is the value set with DIP
switches, button switches, or similar. (For details, refer to "Field settings".)
Frequency is increased or decreased 1 step every 30 seconds. However, under low loads, it is increased or decreased
according to thermostat ON/OFF operation.
Lpm = BU_LP - Lpmt_BU
Freezing capacity
DOWN
Maintenance of
freezing capacity
Freezing
capacity UP
• Reduce the speed of the compressor with
1 step (for every 30 seconds).
• INV_STEP > 1
• Lpm < -0.0147MPa
-0.0147MPa
≤
Lpm
≤
0.0147MPa
-0.0147MPa
≤
Lpm
≤
0.0147MPa
• BU_LP < 0.0294MPa
INV_STEP = Min_STEP
• Increase the speed of the compressor with
1 step (for every 30 seconds).
• INV_STEP < 22
(DIP•SW(A3P_DS1-4, Changeable by service mode, 2 - 4)
• Lpm > 0.0147MPa
• HzUP oil recovery conditions met
• Conditions for low booster unit differential pressure met
• BU_LP: Pressure detected by low pressure sensor of booster unit
• BU_MP: Outdoor unit low pressure sent by outdoor unit by transmission
• Predicted HP: High pressure predicted from the current and Hz of booster unit
• Condition for HzUP oil recovery
• INV_STEP < 9 continues for cumulative 30 min. or more
• BU_LP > 0.0588MPa
• Releasing condition for HzUP oil recovery
INV_STEP
≥
9 continues for cumulative 5 min. or more
• Condition for low booster unit differential pressure
• Predicted HP–BU_LP < 0.294MPa
• BU_MP–BU_LP < 0.294MPa
• INV_STEP < 12
• BU_MP < 0.392MPa
• BU_LP > 0.0588MPa
• Releasing condition for low booster unit differential
pressure: Any but those above
&
Lpmt_BU = f(Tst_BU): Saturation pressure corresponding to target evaporating temperature