Oil Return Cycle - GE ASH220NCDWA Service Manual

Oil Return Cycle

When the compressor is operating at low load
conditions, or the operating frequency has
been below 70Hz continuously for 4 hours,
the system will enter the oil return cycle. This
ensures that oil which may be trapped within
the system at low loads will return to the
compressor crankcase.
If a 4-hour low speed run time has occurred,
the oil return procedure initiates by
automatically ramping up the compressor
speed to at least 85Hz for a pre-set time, up
to a 9-minute maximum. The higher speed
will wick hiding oil into the now faster-moving
refrigerant and deposit it in the compressor
crankcase. To avoid occupant discomfort
when the oil return cycle is active, the indoor
fan shuts off.
Should an error code result in a system
shutdown, the oil return cycle timing will
resume when the error code has been cleared.
If the system stops during an oil return cycle due to an error code, the cycle timing will resume
when the system restarts after the error is cleared.
If there is a switch from heating to cooling, or from cooling to heating during the oil return cycle
Operations
timing, and the system stops due to an error code, the oil return cycle will occur immediately
when the error code is cleared.
Oil Return in Cooling Mode:
Oil Return in Cooling Mode
Send oil return signal
Inverter compressor
auto frequency
running indoor EEV
auto angle
stopped indoor EEV
OFF angle 5(E)
Outdoor motor AUTO
running indoor motor AUTO
stopped indoor motor STOP
4-way valve OFF
Oil Return Exit Conditions, Cooling:
Oil Return Exit Conditions, Cooling:
Oil Return Exit Conditions, Cooling:
＆
OR
OR
Oil Return in Heating Mode
Send oil return signal Max. 10 minutes
Oil Return in Heating Mode
Oil Return in Heating Mode
Oil Return in Heating Mode
Inverter compressor
Send oil return signal
Send oil return signal
Inverter compressor
indicated FQCY
Inverter compressor
indicated FQCY
Outdoor motor
0HZ
Outdoor motor AUTO
Outdoor motor 4-way valve AUTO
4-way valve ON
4-way valve ON
All expansion valves
Indoor fan motor
All expansion valves
auto angle
All expansion valves
auto angle
Indoor fan motor ON
Indoor fan motor ON
Oil Return Exit Conditions, Heating:
OFF
OFF
Oil Return Exit Conditions, Heating:
Oil Return Exit Conditions, Heating:
Max. 9 minutes (E)
OR
OR
＆
OUTDOOR TECHNICAL OVERVIEW
oil return begins
60s
Oil return frequency
350 pulses(E)
80(E)
AUTO (TC or ambient temp. control)
AUTO (set fan speed)
STOP
OFF
1 minute later after oil return is over
Td Tc
‐ ＞86℉（30 ℃）
＆
OR OR Ts Tc2AVE
‐
Tc2AVE＜
1 minute later after oil return is over
Max. 10 minutes
1 minute later after oil return is over
Td Tc
‐ ＞86℉（30 ℃）
＆
Td Tc
‐ ＞86℉（30 ℃）
OR Ts Tc2AVE
＞86℉（30 ℃）
‐
OR Ts Tc2AVE
＞86℉（30 ℃）
‐
Tc2AVE＜ -31℉（-35 ℃）
Tc2AVE＜ -31℉（-35 ℃）
Max. 10 minutes
oil return begins
60s
indicated FQCY oil return FQCY
oil return begins
oil return begins
0HZ
60s
oil return FQCY
5s
60s
oil return FQCY
AUTO
0HZ
AUTO (TC control)
5s
5s
ON
AUTO (TC control)
AUTO (TC control)
OFF
450 pulses
OFF
OFF
auto angle
450 pulses
450 pulses
350 pulses
350 pulses
ON
OFF
Max. 9 minutes (E)
OR OR Td Tc
‐ ＜
to count)
Max. 9 minutes (E)
Ts Tc2AVE
＆ ‐
OR Td Tc 68℉(20 ℃)
‐ ＜
OR Td Tc 68℉(20 ℃) for 30s continuously(5 minutes later, begin
begin to count)
‐ ＜
to count)
to count)
Running for min. 5 minutes
Ts Tc2AVE 59℉(15 ℃)
＆ ‐ ＜
Ts Tc2AVE 59℉(15 ℃)
‐ ＜
begin to count)
begin to count)
Running for min. 5 minutes
Running for min. 5 minutes
oil return over
ref. eliminated 30s
auto frequency
Low frequency
auto angle
120 pulses(E)
OFF angle 5(E)
AUTO
AUTO
STOP
OFF
＞86℉（30 ℃）
-31℉（-35 ℃）
oil return over
60s
oil return over
oil return over
60s soft startup
60s soft startup
0HZ
0HZ
AUTO
AUTO
450 pulses
350 pulses
15s
15s
450 pulses
450 pulses
auto angle
auto angle
Cold air proving mode
Cold air proving mode
Cold air proving mode
68℉(20 ℃) for 30s continuously(5 minutes l
59℉(15 ℃) for 30s continuously(5 min
＜
for 30s continuously(5 minutes later, begin
for 30s continuously(5 minutes later,
for 30s continuously(5 minutes later,
B-15
soft startup
0HZ
AUTO
15s
auto angle