Oil Return Control; Conditions For Executing Oil Control - Daikin VRV Inverter K Series Manual

SI-05C.BOOK Page 225 Monday, November 6, 2000 4:13 PM
SiE-05C
4.3

Oil Return Control

In order to recover refrigeration oil, when total compressor operation capacity equals the reference values,
the capacity is increased, all solenoid valves in the system are fully opened and the oil is recovered at each
compressor.
4.3.1

Conditions for Executing Oil Control

Total compressor operating time = point when approx. 8 hours elapses (Differs somewhat according to
operation status.)
<Heat Pump System>
Operating contents
When cooling
When heating
1 minute
elapses
Preparation
for oil return
Upper limit frequency
limited to 38 Hz + ON
Liquid refrigerant collected in
indoor unit returned to receiver
Functions PLUS Series
Step 1: Collected oil is recovered.
INV outdoor unit STD outdoor unit 1
Compressor
(106Hz + ON) +
EEV
2000pls
Outdoor unit fan H + ON
Outdoor unit heat exchanger
Condenser
Solenoid valve for oil discharge
Injection ON + OFF
Hot gas
Outdoor unit suction pipe temp. ≤ Te + 10˚C
at when either 6 min. or 4 min. elapses.
Step 2: Refrigerant is discharged from accumulator.
INV outdoor unit STD outdoor unit 1
Compressor (60Hz + ON)
+
EEV
Outdoor unit fan H + ON
Outdoor unit heat exchanger Condenser
Solenoid valve for oil discharge
Injection
ON + OFF
Hot gas ON at Lp < 1.0 k
Step 1: 4-way valve switched (30 sec. after start)
INV outdoor unit STD outdoor unit 1
Compressor
(38Hz + ON) +
EEV
2000pls
Outdoor unit fan H + ON
Outdoor unit heat exchanger
Condenser
Solenoid valve for oil discharge
Injection ON + OFF
Hot gas
30 seconds elapse
Step 2: Collected oil is recovered.
INV outdoor unit STD outdoor unit 1
Compressor
(106Hz + ON) +
EEV
2000pls
Outdoor unit fan H + ON
Outdoor unit heat exchanger
Condenser
Solenoid valve for oil discharge
Injection ON + OFF
Hot gas
Outdoor unit suction pipe temp. ≤ Te + 10˚C
at when either 6 min. or 4 min. elapses.
Step 3: Refrigerant is discharged from accumulator. (3 minutes)
INV outdoor unit STD outdoor unit 1
Compressor (60Hz + OFF)
+
EEV
Outdoor unit fan H + ON
Outdoor unit heat exchanger
Evaporator
Solenoid valve for oil discharge
Injection ON + OFF
Hot gas ON at Lp < 2.5 k
STD outdoor unit 2
(ON + ON) + (ON + ON)
2000pls 2000pls
H + ON H + ON
Condenser Condenser
OFF
ON + OFF ON + OFF
OFF
STD outdoor unit 2
(ON + OFF) + (ON + OFF)
SH control
H + ON H + ON
Condenser Condenser
ON
ON + OFF ON + OFF
STD outdoor unit 2
(ON + OFF) + (ON + OFF)
2000pls 2000pls
H + ON H + ON
Condenser Condenser
ON
ON + OFF ON + OFF
ON
STD outdoor unit 2
(ON + ON) + (ON + ON)
2000pls 2000pls
H + ON H + ON
Condenser Condenser
ON
ON + OFF ON + OFF
OFF
STD outdoor unit 2
(ON + OFF) + (ON + OFF )
SH control
H + ON H + ON
Evaporator Evaporator
OFF
ON + OFF ON + OFF
: http://splitoff.ru/tehn-doc.html
Outline of Control
2
(k:kg/cm )
3 minutes elapses
or suction
pressure < 1.0
Quit
3 minutes
elapses or
HP > 21k
Quit
(VF107)
225