Oil Control - Panasonic U-8ME1E8E Service Manual

6. Indoor Units Control from the CCU

7. Oil Control

EEPROM setting in main outdoor unit
CODE: 2B
Setting No XX
20
30
40
50
1
60
* The drain pump always operates when the indoor unit is thermostat ON in cooling operation.
* Once the drain pump operates, it keeps operating for 20 minutes.
In the above 2 cases, the drain pump operates by the signal of indoor PCB, not by CCU.
6-5. Discharge air temperature control
For Type F1, M1, E1 indoor units, discharge air temperature is controlled from the CCU to prevent condensation
on duct surface in cooling operation. The CCU monitors and adjusts DTo of indoor unit. The adjustment is made
by compressor capacity and MOV operation in the indoor unit.
* DTo: Cooling (Discharge air temperature) - (Preset discharge air temperature)
Heating (Preset discharge air temperature) - (Discharge air temperature)
Situation in which indoor unit stops by discharge air temperature control
- TDo ≦ -3.5deg, and this condition continues 7 minutes
- TDo ≦ -2.0deg, and this condition continues (20 + XX) minutes
*The above mentioned "XX" is able to set in EEPROM of the main outdoor unit
EEPROM setting in main outdoor unit
CODE: E1
Setting No
-20
-19
-18
0
10
*In heating operation, this function virtually does not work because preset discharge air temperature is 50℃ and
this is sufficiently higher than actual discharge temperature.
For preset discharge air temperature that is set in the indoor unit is able to change, refer to manual for indoor unit.
7-1. Oil Level
Oil level Meaning
2 Suffi cient
1 Slightly low
0 Extremely low
At the time immediately after the oil level changes from 2 to 1, there is a specified amount of oil in the
compressor. Namely, soon after the oil level is changed to 1, the oil in the compressor is sufficient. If the oil level
"0" indication continues for more than 5 to 10 minutes, it seems short of oil in the system. Check valves related to
oil recovery operation, the refrigerant tubing and for any oil leakage.
20 minutes
30 minutes (factory preset mode)
40 minutes
50 minutes
60 minutes
XX
-20
-19
-18
Interval of "1"
0 (factory preset mode)
10
Conditions of oil
The compressor contains suffi cient oil.
There will be a risk of oil shortage soon.
The compressor oil is short against
required level for normal operation.
Control Functions - Outdoor Unit
There is no problem.
Confi rm that oil is returned after
performing the oil recovery control
operation.
Confi rm that oil level is recovered to the
required level after performing the oil
recovery control between systems.
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2WAY SYSTEM
Judgement