Daikin VRV K - Page 28

Functions Si-95
18 Functions Inverter K Series
1.5.3 Pump Down Start
If the compressor stops running with refrigerant still remaining in the accumulator, in order to prevent wet
operation at the next compressor starting, it will perform pump down start with a completely dry
accumulator, then it will operate normally.
Pump down start should be performed if the unit is in any of the conditions given below when pressure
equalizing control has been completed before start.
If R3-1T is less than 95˚C and the unit is in any of the following conditions.
◆ Within 10 minutes of the compressor starting
◆ Defrosting or during oil return
◆ Within 20 minutes of completion of defrost or oil return
◆ Outdoor air temperature (R1T) < 0ºC
◆ Oil temperature (R5T) < Te + 10ºC
Te : Low pressure equivalent saturated temperature
Operation During
Pump Down Start
◆ Y2S: Hot gas bypass solenoid valve
◆ Y3S: Injection solenoid valve
1.5.4 Heating Lay-Up Start
If the compressor hasn’t run for a long time and the refrigerant isn’t circulated, foaming could cause a lack
of oil when the compressor is started at the next time. It should therefore perform heating lay-up start to
keep the low pressure from dropping too low in the following cases.
◆ First starting after being power ON.
◆ Starting after the compressor has been stopped or thermostat OFF for more than continuous 24 hours.
Operation During
Heating Lay-Up
Start
Make the compressor’s upper limit frequency 60Hz (60Hz+OFF) for 10 minutes 20 seconds after the
compressor starts.
∗ If the low pressure becomes < 1.5kg/cm
2
(0.147MPa) within 10 minutes after starting,
Y2S → ON
Outdoor EV → 0 pulses
← 11 min. 30 sec. →
1 min. 5 min. 30 sec. 30 sec. 4 min. 30 sec.
Compressor 42Hz+OFF 42Hz+OFF 30Hz+OFF 116Hz+OFF
Outdoor unit EV 0 pulses 0 pulses 0 pulses 150 pulses
Outdoor unit fan H tap (H+ON) H tap (H+ON) H tap (H+ON) H tap (H+ON)
Y2S ON ON ON OFF ON/OFF
(LP protection
control)
Y3S, Y4S ON ON/OFF
(Td protection control)
ON/OFF
(Td protection control)
ON/OFF
(Td protection control)
SI-95.BOOK Page 18 Friday, March 31, 2000 10:59 AM